landslide susceptibility mapping at golestan province iran a comparison between frequency ratio dempster shafer and weights of evidence models abstract the purpose of the present study is to investigate the landslide susceptibility mapping using three statistical models such as frequency ratio dempster shafer and weights of evidence at southern part of golestan province at first landslide locations were identified from the interpretation of aerial photographs and field surveys a total of 392 landslides were mapped in gis out of which 275 70 locations were chosen for the modeling purpose and the remaining 118 30 cases were used for the model validation then layers of the landslide conditioning factors were prepared the relationship between the conditioning factors and the landslides were calculated using three models for verification the results were compared with landslides which were not used during the training of the models subsequently the roc receiver operating characteristic curves and area under the curves auc for three landslide susceptibility maps were constructed and the areas under curves were assessed for validation purpose the validation results showed that the area under the curve for frequency ratio dempster shafer and weights of evidence models are 0 8013 80 13 0 7832 78 32 and 0 7460 74 60 with prediction accuracy 0 7516 75 0 7396 73 and 0 6998 69 respectively the results revealed that frequency ratio model has higher auc than the other models in general all the three models produced reasonable accuracy the resultant maps would be useful for general land use planning

earthquake induced landslide susceptibility mapping using an integrated ensemble frequency ratio and logistic regression models in west sumatera province indonesia an 8 richter scale rs earthquake struck west sumatra on wednesday 30 september 2009 at 17 16 pm which led to huge number of landslides hence a comprehensive landslide susceptibility mapping lsm should be produced in order to reduce the damages to people and infrastructures in the international landslide literature various statistical methods such as frequency ratio fr and logistic regression lr have been widely used individually for lsm but they have some weaknesses fr which is able to perform bivariate statistical analysis bsa assesses the influence of classes of each conditioning factor on landslide occurrence however the correlation between the factors is mostly neglected on the other hand lr is able to analyze the relationship among the factors while it is not capable to evaluate the classes of each landslide conditioning factor this paper aims to propose an ensemble method of fr and lr in order to overcome their weak points for lsm a landslide inventory map with a total of 87 landslide locations was extracted from various sources then the landslide inventory was randomly divided into two datasets 70 for training the models and the remaining 30 was used for validation purpose the landslide conditioning factors consist of altitude curvature river spi rainfall soil type soil texture land use cover lulc peak ground acceleration pga geology slope aspect lineament and topographic wetness index twi four pga of 7 5 8 8 6 and 9 were acquired and pga 8 which was related to the 2009 earthquake was used to generate the model finally the produced landslide susceptibility maps were validated using an area under the roc curve method for the model which was derived by pga 8 the validation results showed 84 and 78 success and prediction rates respectively furthermore the prediction rates for the models made by pga 7 2 8 6 and 9 are 79 78 and 81 respectively the result proved the reasonable efficiency of the proposed method for earthquake induced landslide susceptibility mapping also the proposed ensemble method can be used in other hazard studies as it is capable to produce rapid and accurate assessment for disaster management and decision making

compression behaviour of minerogenic low energy intertidal sediments existing geotechnical approaches that describe volumetric changes in intertidal sediments in response to applied vertical effective stresses are limited by a lack of empirical research into their one dimensional compression behaviour in this paper we address this deficiency by presenting the results of an investigation into the compression behaviour of minerogenic low marsh and tidal flat sediments we have tested samples of these sediment types obtained from greatham creek cowpen marsh tees estuary uk analysis of physical properties and oedometer compression tests demonstrates that contrary to the implicit assumptions of existing models the surface sediments studied are overconsolidated structural variability between samples arises due to sedimentological factors notably variations in organic content we attribute overconsolidation to tidal exposure and falls in groundwater level that permit desiccation and cause capillary suction stresses greater rates of compression with respect to effective stress occur in sediments with higher initial voids ratios and more open unstable initial structures variability in structure decreases with application of higher effective stresses due to the destructuration of the sediments which also creates increased homogeneity of compression behaviour under higher effective stresses we subsequently develop a new conceptual framework to describe compression behaviour in minerogenic intertidal sediments that incorporates overconsolidation we advocate a statistical approach that accounts for structural variability and variations in compression behaviour at effective stresses less than and greater than the yield stress we argue that our conceptual framework is broadly applicable to minerogenic intertidal sediments at different locations and burial depths within holocene stratigraphic sequences providing site specific compression data are collected inter site transfer and application of measured material properties should not be undertaken due to local variations in compression behaviour resulting from varying ecological sedimentological geochemical climatic geomorphic and hydrographic conditions the individual characteristics of different field locations should be carefully considered before the suggested framework is routinely applied

patterns rates and possible causes of saltmarsh erosion in the greater thames area uk the estuary dominated coast of the greater thames in england has experienced rapid lateral erosion and internal dissection of saltmarshes this paper provides an overview of saltmarsh development in this area and re examines the role of environmental and human forcing factors it draws on documentary evidence including historical maps survey data and time series data of forcing factors lateral marsh retreat began in the 19th century in the medway and blackwater estuaries followed by other estuaries in the greater thames region at the beginning of the 20th century the outer estuaries and the wider parts of the inner estuaries especially have experienced erosion erosion has been modest in wave sheltered areas e g the colne and the inner crouch in the 1960s and more widely the 1970s a phase of rapid erosion took place with erosion rates of up to ca 16 ha year 1 per site notably along the open coast of dengie and foulness and in the blackwater and thames estuaries at all sites vertical sediment accretion was well able to keep up with sea level rise over the past century evidence indicates that there may have been several causes for the erosion of saltmarshes these are notably land claim and embankment construction increasing the tidal range and current velocities and a continuous rise of especially high and extreme water levels the latest episode of rapid erosion in the 1970s is largely attributed to changes in the wind wave climate for example erosion at wave exposed sites coincided with a peak in high magnitude waves combined with a high incidence of southeasterly waves the study shows that many factors including natural forcing factors and human activities have to be taken into account when explaining saltmarsh development

late cretaceous palaeocene subduction collision exhumation of a microcontinent along the northern active margin of the southern neotethys evidence from the alanya massif and the adjacent antalya complex s turkey abstract the alanya massif represents a microcontinent that underwent subduction exhumation related to collision with the larger tauride microcontinent to the north during latest cretaceous palaeocene intermediate structural level blueschist melange in the northwest gundogmus area encompasses ductile deformed meta basaltic rocks meta cherts and minor serpentinite in a lower grade meta mudrock matrix the meta basaltic protoliths mainly formed in a subduction influenced setting together with less common oib and e morb late permian platform slope carbonates were intersliced during late stage brittle thrusting and directly over ridden by a lower grade greenschist facies late permian early triassic aged platform unit the blueschist melange is interpreted as an oceanic subduction complex that was obducted southwards related to microcontinental collision intermediate structural level hp lt blueschist ecologites farther south alanya area indicate that the alanya massif represents variably subducted exhumed continental crust both subduction and exhumation took place during the latest cretaceous prior to late palaeocene early eocene marine transgression late precambrian protoliths of eclogitic hp lt rocks and also similar aged amphibolite facies meta basic intrusions farther southeast anamur area are interpreted to have formed in a panafrican cadomian late stage back arc setting late triassic basaltic rocks in the antalya complex structurally beneath and to the north erupted in a rift setting we restore the mesozoic palaeogeography from north to south as tauride microcontinent antalya rift basin alanya micrcontinent s neotethys the subduction exhumation history may serve as a model for similar active margin collisional settings elsewhere

a comparative study of landslide susceptibility mapping using weight of evidence logistic regression and support vector machine and evaluated by sbas insar monitoring zhouqu to wudu segment in bailong river basin china the determining of landslide prone areas in mountainous terrain is essential for land planning and hazard mitigation in this paper a comparative study using three statistical models including weight of evidence model woe logistic regression model lr and support vector machine method svm was undertaken in the zhouqu to wudu segment in the bailong river basin southern gansu china six conditionally independent environmental factors elevation slope aspect distance from fault lithology and settlement density were selected as the explanatory variables that may contribute to landslide occurrence based on principal component analysis pca and chi square test the relation between landslide distributions and these variables was analyzed using the three models and the results then used to calculate the landslide susceptibility ls the performance of the models was then evaluated using both the highly accurate deformation signals produced by using the small baseline subset interferometric synthetic aperture radar technique and receiver operating characteristic roc curve results show more deformation points in areas with high and very high ls levels and also more stable points in areas with low and very low ls levels for the svm model in addition the svm has larger area under the roc curve it indicates that the svm has better prediction accuracy and classified ability for the interpretability the woe derives the class of factors that most contributed to landsliding in the study area and the lr reveals that factors including elevation settlement density and distance from fault played major roles in landslide occurrence and distribution whereas the svm cannot provide relative weights for the variables the outperformed svm could be employed to determine potential landslide zones in the study area outcome of this research would provide preliminary basis for general land planning such as choosing new urban areas and infrastructure construction in the future as well as for landslide hazard mitigation in bailong river basin

petrology of the ispendere malatya ophiolite from the southeast anatolia implications for the late mesozoic evolution of the southern neotethyan ocean

lidar supported prediction of slope failures using an integrated ensemble weights of evidence and analytical hierarchy process the present study investigates a potential application of different resolution topographic data obtained from airborne lidar and an integrated ensemble weight of evidence and analytic hierarchy process woe ahp model to spatially predict slope failures previously failed slopes of the pellizzano italy were remotely mapped and divided into two subsets for training and testing purposes 1 2 5 10 15 and 20 m topographic data were processed to extract nine terrain attributes identified as conditioning factors for landslides slope degree aspect altitude plan curvature profile curvature stream power index topographic wetness index sediment transport index and topographic roughness index landslide slope failure susceptibility maps were produced using a single woe model 1 an ensemble woe ahp model that used all conditioning factors model 2 and an ensemble woe ahp model that only used highly nominated conditioning factors model 3 the validation results proved the efficiency of high resolution 5 m topographic data and the ensemble model particularly when all factors were used in the modeling process model 2 the average success rates and prediction rates for model 2 that used 5 m resolution datasets were 84 26 and 82 78 respectively the finding presented in this paper can aid in planning more efficient lidar surveys and the handling of large datasets and in gaining a better understanding of the nature of the predictive models

evaluation of different machine learning models for predicting and mapping the susceptibility of gully erosion abstract gully erosion constitutes a serious problem for land degradation in a wide range of environments the main objective of this research was to compare the performance of seven state of the art machine learning models svm with four kernel types bp ann rf and brt to model the occurrence of gully erosion in the kashkan poldokhtar watershed iran in the first step a gully inventory map consisting of 65 gully polygons was prepared through field surveys three different sample data sets s1 s2 and s3 including both positive and negative cells 70 for training and 30 for validation were randomly prepared to evaluate the robustness of the models to model the gully erosion susceptibility 12 geo environmental factors were selected as predictors finally the goodness of fit and prediction skill of the models were evaluated by different criteria including efficiency percent kappa coefficient and the area under the roc curves auc in terms of accuracy the rf rbf svm brt and p svm models performed excellently both in the degree of fitting and in predictive performance auc values well above 0 9 which resulted in accurate predictions therefore these models can be used in other gully erosion studies as they are capable of rapidly producing accurate and robust gully erosion susceptibility maps gesms for decision making and soil and water management practices furthermore it was found that performance of rf and rbf svm for modelling gully erosion occurrence is quite stable when the learning and validation samples are changed

a comparison of frequency ratio and fuzzy logic models for flood susceptibility assessment of the lower kosi river basin in india the kosi megafan region of eastern bihar india comprising of eight districts is regularly afflicted by large floods that cause extensive damage mapping the possible inundation susceptible zones in the region accurately is therefore paramount for land resource conservation and livelihood preservation this paper compares the relative efficiency of two flood zonation methods the frequency ratio and fuzzy logic models for flood susceptibility evaluation and delineation flooded extents from two past events were combined to create the training dataset which was then compared individually with respective maps of 12 well documented causal factors of inundation to gauge their relative influence on the flood spread these were merged using the two models to generate the respective flood susceptibility maps which were subsequently validated using the receiver operating characteristics curve and the seed cell area index methods results revealed that an enhanced fuzzy logic model prepared by assigning relative weights to the respective causal factors as obtained from their analysis in the frequency ratio model was more accurate and robust in demarcating flood susceptibility zones as was further ascertained by comparison with a recent flood event thereby providing a novel way to merge these methods the western and southern tracts of the region were found to be more inundation prone with the greatest risk posed along the narrow interfluve between the kosi and ganga rivers prior to their confluence further east the districts most likely to be inundated were identified by computing their respective proportionate areas under the very highly susceptible flood class

recent estuarine sedimentation rates from shallow inter tidal environments in western scotland implications for future sea level trends and coastal wetland development during the mid late holocene large sections of the scottish coastline have been characterized by falling relative sea levels resulting from differential glacio isostatic uplift of this region of northern britain the complex interplay between crustal and sea level movements continues to influence the morphological development of the scottish coast a number of geophysical models predict ongoing uplift of the scottish landmass however a number of recent studies based upon the analysis of satellite altimetry data indicate a late 20th century acceleration in the rate of eustatic sea level rise detailed geochemistry radiometric dating and diatom analysis on selected sediment cores from four mature coastal marsh environments in argyll western scotland provides an opportunity to investigate the linkages between twentieth century crustal movements eustatic sea level rise and recent rates of sedimentation recorded within marsh sediments across the proposed scottish glacio isostatic uplift dome solid phase major and trace element geochemistry has been used to examine the extent to which post depositional physical disturbance and or chemical reactions may have influenced the reliability of the radiometric dating methods geochemical data indicate that the evolution of these marsh environments has not been significantly influenced by physical disturbance and overall the supply of minerogenic material to the marshes has been quite uniform vertical distributions of 210pbexcess and 137cs activity have been measured and used to develop models of recent marsh vertical accretion dating of the cores reveals subtle variations in the rates of sediment accumulation over the last c 70 years between sites for much of the last hundred years or so sedimentation rates have been in good overall agreement with various estimations for sea level rise although at the more easterly sites these estimates are generally exceeded however quasi equilibrium between marsh sedimentation and sea level rise for much of the twentieth century is indicated from the diatom analysis over the most recent period of marsh development 10 years a significant increase in the rate of surface sedimentation is recorded at all sites across the study area diatom analysis of these surface layers reveals an increase in the relative abundance of marine polyhalobous taxa in the near surface sediments this signifies a very recent increase in the rate of regional relative sea level rise indicating that a regional threshold in coastal forcing has now been exceeded these findings provide clear evidence that recent relative sea level rise is now outpacing estimated rates of glacio isostatic adjustment gia across the proposed scottish uplift dome

holocene crustal movements and sea level changes in great britain crustal downwarping has occurred throughout southern and south eastern england and most of wales for at least the last 4000 years but the type of movement in some areas of southern and eastern england is more complicated than simple linear subsidence highest estimated rates of subsidence since 4000 bp are for the thames estuary and norfolk up to 2 mm yr glacio isostatic processes have resulted in uplift in northern england and mainland scotland the rates of uplift have decreased throughout the holocene estimates for the present range from zero in south lancashire and the tees estuary to over 1 mm yr though less than 2 mm yr in central scotland over 400 sea level index points from the databank of 904 cases collected for igcp project 200 are grouped into 15 main areas and used to investigate the nature of crustal movements in great britain since 8800 bp but there are significant deficiencies in available data which constrain the analysis

a portable electrical based percussion coring system for use in deep water this article describes a sediment coring system that can be used in deep water 30 to 60 m with no aid from divers the system is light and compact enough to be operated by three persons and transported in a small boat and or in a small airplane a core tube penetrates into sediments with the force caused by percussion of a water proof electric hammer driven by a generator on the boat with this device four sand cores were retrieved from a lagoon floor at depths ranging from 40 m to 58 m a flexible vinyl tube is used as a core liner and it provides an exact measure of core recovery

landslide susceptibility mapping by comparing the wlc and wofe multi criteria methods in the west crete island greece in the current research the weighted linear combination wlc and the weights of evidence wofe methods were applied for landslide susceptibility zonation mapping in the chania prefecture of crete island greece several thematic maps representing various landslide conditioning factors such as geology formations faults proximity altitude slope gradient aspect curvature rivers proximity precipitation roads proximity and land use types have been generated in a gis environment three landslide susceptibility maps were created one for each method and a combined one by applying the logistic regression approach to the wlc and wofe susceptibility maps the maps were evaluated and validated using the efficiency rate curve the receiver operator curve and the spatially agreed areas methods the resulting landslide susceptibility maps have uncertainties introduced due to the subjective knowledge of experts in the case of wlc method and to the quality of the recorded landslides sample in the case of the wofe method nevertheless the performance of the three approaches was found to be almost equal with all methods to produce quite satisfactory results besides the comparison of the applied methods the current study contributes to the risk management of the area providing the first landslide susceptibility maps for chania prefecture

shear sense criteria in the antalya and alanya thrust system southwestern turkey evidence for a southward emplacement abstract a northern as opposed to a southern origin of the antalya and alanya nappes in turkey has been a contentious issue among geologists the two hypotheses are essentially supported by contrasting geometrical and sedimentary arguments to introduce new information into the debate we have been analyzing for shear sense criteria in thrust contacts these data give clear evidence for a south directed vergence these results suggest that both the antalya and alanya nappes were derived from the same oceanic basin and continental margin as the other tauric nappes whose northern origin has long been recognized

groundwater potential mapping at northeastern wasit and missan governorates iraq using a data driven weights of evidence technique in framework of gis in this study a data driven weights of evidence woe technique was used to demarcate groundwater potential zones at northeastern missan and wasit governorates iraq using geographic information system gis platform in the first step borehole location inventory map consisting of 143 with relatively high yield 8 l s was prepared then eight influencing groundwater factors namely altitude slope geology land use land cover distance to roads distance to faults aquifer type and depth of wells were prepared and integrated into spatial database the spatial association between borehole locations and each influencing groundwater factors were analyzed and discussed for the analysis of groundwater productivity the studentised contrast c s c of each groundwater factors were spatially overlaid and weighted summed to produce groundwater potential index gwpi map the resulting map was classified into four categories low moderate high and very high according to natural break classification scheme the low gwpi zone covers 30 2 215 km2 the moderate high and very high cover 32 2 349 km2 23 1 649 km2 and 15 1 075 km2 of the total study area respectively the high and very high zones cover approximately 40 of the study area indicating moderate productivity of the aquifer system in the study area the results of the analysis were validated using receiver operating characteristic roc technique the areas under the roc curve auc for success and prediction rates were 0 81 and 0 80 respectively indicating the high capability of woe for modeling groundwater potentiality in the study area result of this study could be used as guide to manage aquifers in these areas and serve as indicator for sustainable management of aquifer systems

ultra high pressure metamorphism and orogenesis an alpine perspective article i nfo the pressure temperature time deformation evolution of the high to ultra high pressure units of the western alps has been progressively refined in the last 40 years leading to several paradigm shifts in the understanding of orogenesis this set of information combined with cretaceous tertiary plate kinematic reconstructions and mesozoic palaeogeography indicates that the western alps represent the amalgamation of a cretaceous and an eocene orogen which developed at the expense of the adriatic and european rifted margins respectively in the cretaceous nne directed drift of the adriatic plate parallel to the inherited jurassic structural trends led to the development of a highly oblique subduction boundary in this setting the canavese zone and parts of the sesia zone derived from the hyper extended adriatic margin underwent deformation and metamorphism at conditions ranging from sub greenschist to eclogite facies a lower eocene switch to nnw directed motion perpendicular to the rift related jurassic structural trends culminated in the collision between the proto alps and the brianconnais block at ca 44 ma as a result the brianconnais domain and parts of its hyper extended margin preserved in the u hp piemonte units were accreted to the orogen continued convergence was subsequently accommodated by subduction of the more external valaisan basin and of the thinned european margin the arrival of thick european continental crust at the subduction zone at ca 35 30 ma marked the onset of the final continental collision to a first order the orogen grew through the progressive episodic accretion of units located towards north westerly positions accretion of subducting units at the front of the orogen was coeval with kinematic reworking of tectonic contacts in the hangingwall units locally resulting in renewed deformation metamorphism

granulometric characterization and evaluation of annually banded mid holocene estuarine silts welsh severn estuary uk coastal change sea level and climate abstract holocene silts salt marshes and highest intertidal supratidal peats are superbly exposed on a 15 km coastal transect which reveals two laterally extensive units of annually banded silts beds 3 7 associated with three transgressive regressive silt peat cycles early sixth early fourth millennium bc bed 3 in places is concordantly and gradationally related to peats above and below but in others transgresses older strata bed 7 also grades up into peat but everywhere overlies a discordance the banding in bed 3 at three main and two minor sites was resolved and characterized texturally at high resolution 2 5 5 mm contiguous slices using laser granulometry ls230 with pids and a comprehensive scheme of data assessment most of bed 3 formed very rapidly at peak values of several tens of millimetres annually in accordance with modelled effects of sea level fluctuations on mature marshes bed concordant and gradational and on marshes growing up after coastal erosion and retreat bed with discordant base using data from the modern severn estuary the textural contrast within bands and its variation between bands points to a variable but overall milder mid holocene climate than today the inter annual variability affected marsh dynamics as shown by the behaviour of the finely divided plant tissues present given local calibration the methodology is applicable to other tidal systems with banded silts in britain and mainland northwest europe

landslide susceptibility mapping in injae korea using a decision tree a data mining classification technique can be applied to landslide susceptibility mapping because of its advantages a decision tree is one popular classification algorithm although hardly used previously to analyze landslide susceptibility because the obtained data assume a uniform class distribution whereas landslide spatial event data when represented on a grid raster layer are highly class imbalanced for this study of south korean landslides a decision tree was constructed using quinlan s algorithm c4 5 the susceptibility of landslide occurrence was then deduced using leaf node ranking or m branch smoothing the area studied at injae suffered substantial landslide damage after heavy rains in 2006 landslide related factors for nearly 600 landslides were extracted from local maps topographic including curvature slope distance to ridge and aspect forest providing age type density and diameter and soil texture drainage effective thickness and material for the quantitative assessment of landslide susceptibility the accuracy of the twofold cross validation was 86 08 accuracy using all known data was 89 26 based on a cumulative lift chart a decision tree can therefore be used efficiently for landslide susceptibility analysis and might be widely used for prediction of various spatial events

petrology of the tekirova antalya ophiolite southern turkey evidence for diverse magma generations and their tectonic implications during neotethyan subduction the sw antalya complex is an assemblage of mesozoic carbonate platform margin and ophiolitic rocks which record the formation and tectonic emplacement of a small mesozoic ocean basin the late cretaceous ophiolitic rocks are located at two localities namely the relatively intact tekirova ophiolite to the east of kemer zone and the dismembered godene ophiolite to the west of kemer zone the tekirova antalya ophiolite comprises harzburgitic tectonites ultramafic to mafic cumulates isotropic gabbros and sheeted dikes numerous isolated dikes ranging in thickness from 5 cm to 10 m intruded the crustal rocks at different structural levels the isotropic gabbros are represented by gabbro diorite and quartz diorite rocks with granular to ophitic subophitic textures the isolated dikes are characterized by dolerite diabase and microdiorite with ophitic intersertal and microgranular textures these rocks exhibit tholeiitic to alkaline compositions new geochemical data presented in this paper from the isolated dikes and isotropic gabbros suggest that there are three main types of parental basic magmas that form the oceanic crustal rocks of the tekirova antalya ophiolite these are 1 iat series which can be referred to the group i isolated dikes and isotropic gabbros 2 low ti boninitic series characterized by the group ii isolated dike and isotropic gabbros and 3 oib type including the group iii isotropic gabbros the geochemical evidence suggests that the crustal rocks of the tekirova antalya ophiolite were generated from a progressive source depletion from island arc tholeiites iat to boninites therefore a fore arc tectonic setting seems likely for the generation of the crustal rocks from the tekirova antalya ophiolite in the southern branch of neotethys during the late cretaceous the oib type alkaline isotropic gabbros are thought to have resulted from either 1 a late stage magmatic activity fed by melts that originated within an asthenospheric window due to slab break off or 2 subduction of a ridge system which generated oib source across the asthenospheric window that has been no influence of fluids from the subducted slab into the overlying mantle wedge shortly before the emplacement of the tekirova antalya ophiolite onto the tauride platform

artificial neural networks applied to landslide susceptibility assessment abstract landslide hazard mapping is often performed through the identification and analysis of hillslope instability factors usually managed as thematic data within geographic information systems gis in heuristic approaches these factors are rated by the attribution of scores based on the assumed role played by each of them in controlling the development of a sliding process other more refined methods based on the principle that the present and the past are keys to the future have also been developed thus allowing less subjective analyses in which landslide susceptibility is assessed by statistical relationships between past landslide events and hillslope instability factors the objective of this research is to define a method with the ability to forecast landslide susceptibility through the application of artificial neural networks anns the riomaggiore catchment a subwatershed of the reno river basin located in the northern apennines italy was chosen as an ideal test site as it is representative of many of the geomorphological settings within this region in the present application two different anns used in classification problems were set up and applied one belonging to the category of multi layered perceptron mlp and the other to the probabilistic neural network pnn family the hillslope factors that have been taken into account in the analysis were the following a lithology b slope angle c profile curvature d land cover and e upslope contributing area these factors have been classified on nominal scales and their intersection allowed 3342 homogeneous domains unique condition unit ucu to be singled out which correspond to the terrain units utilized in this analysis the model vector used to train the anns is a subset of that derived from the production of unique condition units and consists of 3342 records organized in input and output variable vectors in particular the hillslope factors once classified on nominal scales as binary numbers represent the 19 input variables while the presence absence of a landslide in a given terrain unit is assumed to be the output variable the comparison between the most up to date landslide inventory of the riomaggiore catchment and the hazardous areas as predicted by the anns showed satisfactory results with a slight preference for the mlp for this reason this is an encouraging preliminary approach towards a systematic introduction of ann based statistical methods in landslide hazard assessment and mapping

sedimentary response of pagham harbour southern england to barrier breaching in ad 1910 this paper examines the evolution of pagham harbour southern england following storm induced breaching of a protective barrier in ad 1910 stratigraphic studies of sediments collected from intertidal areas show the presence of a distinct stratigraphic horizon in the northeast of pagham harbour at ca 0 to 1 0 m ordnance datum od radiometric data indicate that this horizon is a reclamation surface formed after land claim in ad 1846 following marine flooding in ad 1910 sediment has accreted relatively rapidly at a broadly constant rate of between 4 and 8 mm a 1 wave and or tidal energy have decreased and extensive marshes have developed an asymptotic reduction in sediment accretion rate through time as predicted in various theoretical models of salt marsh accretion is not observed over the entire pagham harbour area the period between ad 1948 and ad 1986 has seen an average marsh loss of 0 0087 km2 a 1 which is relatively small in comparison with other more exposed sites in the local area historically breached sites such as pagham harbour are common around european coasts and these provide important natural laboratories within which the medium term decadal to centennial coastal response to barrier breaching and to managed realignment coastal protection schemes can be assessed

blueschist metamorphism in an active subduction zone the high pressure low temperature metamorphic rocks known as blueschists have long been considered to form in subduction zones where the descent of a relatively cold slab leads to the occurrence of unusually low temperatures at mantle pressures until now however the link between blueschist facies rocks and subduction zones has been indirect relying on a spatial association of blueschists with old subduction complexes and estimates of the geothermal gradients likely to exist in subduction zones here we strengthen this link by reporting the discovery of blueschist facies minerals lawsonite aragonite sodic pyroxene and blue amphibole in clasts from a serpentinite seamount in the forearc of the active mariana subduction zone the metamorphic conditions estimated from the mineral compositions are 150 250 c and 5 6 kbar 16 20 km depth the rocks must have been entrained in rising serpentine mud diapirs and extruded from mud volcanoes onto the sea floor further study of these rocks may provide new insight into the tectonics of trench forearc systems and in particular the processes by which blueschist facies clasts come to be associated with forearc sediments in ancient subduction complexes

a landslide susceptibility model using the analytical hierarchy process method and multivariate statistics in perialpine slovenia abstract landslides cause damage to property and unfortunately pose a threat even to human lives good landslide susceptibility hazard and risk models could help mitigate or even avoid the unwanted consequences resulted from such hillslope mass movements for the purpose of landslide susceptibility assessment the study area in the central slovenia was divided to 78 365 slope units for which 24 statistical variables were calculated for the land use and vegetation data multi spectral high resolution images were merged using principal component analysis method and classified with an unsupervised classification using multivariate statistical analysis factor analysis the interactions between factors and landslide distribution were tested and the importance of individual factors for landslide occurrence was defined the results show that the slope the lithology the terrain roughness and the cover type play important roles in landslide susceptibility the importance of other spatial factors varies depending on the landslide type based on the statistical results several landslide susceptibility models were developed using the analytical hierarchy process method these models gave very different results with a prediction error ranging from 4 3 to 73 as a final result of the research the weights of important spatial factors from the best models were derived with the ahp method using probability measures potentially hazardous areas were located in relation to population and road distribution and hazard classes were assessed

digital terrain modelling a review of hydrological geomorphological and biological applications the topography of a catchment has a major impact on the hydrological geomorphological and biological processes active in the landscape the spatial distribution of topographic attributes can often be used as an indirect measure of the spatial variability of these processes and allows them to be mapped using relatively simple techniques many geographic information systems are being developed that store topographic information as the primary data for analysing water resource and biological problems furthermore topography can be used to develop more physically realistic structures for hydrologic and water quality models that directly account for the impact of topography on the hydrology digital elevation models are the primary data used in the analysis of catchment topography we describe elevation data sources digital elevation model structures and the analysis of digital elevation data for hydrological geomorphological and biological applications some hydrologic models that make use of digital representations of topography are also considered

seasonal changes in surface level of a salt marsh creek nineteen surveys were carried out over a two year period to determine the surface height of a salt marsh creek located on the north side of the river esk cumbria england an aga 112 electromagnetic distance measurer mounted on a wild ti theodolite was used in conjunction with acrylic reflectors to follow the form of the ground the results showed that there were no significant net trends in surface level although seasonal variations of the order of 2 cm occurred vegetated areas responded in similar fashion to bare surfaces it is thought that the elevational changes were attributable to the swelling of clay particles during the winter months rather than the effects of erosion and accretion

temporal variation of accumulation rates on a natural salt marsh in the 20th century the impact of sea level rise and increased inundation frequency abstract salt marshes are potentially threatened by sea level rise if sediment supply is unable to balance the rising sea a rapid sea level rise is one of the pronounced effects of global warming and global sea level is at present rising at an elevated rate of about 3 4 mm y 1 on average this increasing rate of sea level rise should make it possible to study the effect of rapidly rising sea level on salt marsh accumulation however such an understanding is generally hampered by lack of available data with sufficient precision here we present a high precision dataset based on detailed radiometric measurements of 137cs in 10 sediment cores retrieved at a natural and unmanaged micro tidal salt marsh two distinct 137cs peaks were found in all cores one peak corresponding to the 1963 maximum caused by testing of nuclear weapons in the atmosphere and the other to the chernobyl accident in 1986 salt marsh accretion has generally kept pace with sea level rise since 1963 but comparison of the accumulation rates of minerogenic material in the period 1963 1986 and 1986 2003 revealed a slight decrease in accumulation with time in spite of an observed increase in inundation frequency the observed decrease in sediment deposition is significant and gives reason for concern as it may be the first sign of a sedimentation deficiency which could be threatening this and other salt marshes in the case of a rapidly rising sea level our work demonstrates that the assumption of a constant relationship between salt marsh inundation and sediment deposition is not necessarily valid even for a salt marsh that receives most of its allocthonous sediment from the adjacent sea the apparent decrease in sediment deposition indicates that the basic assumption of sufficient sediment supply used in contemporary models dealing with salt marsh accretion is most probably not valid in the present case study and it may well be that this is also the case for many other salt marshes especially if sea level continues to rise rapidly as indicated by some climate change scenarios

quantitative assessment of landslide susceptibility along the xianshuihe fault zone tibetan plateau china the xianshuihe fault xsf zone is a sinistral slip fault system on the eastern margin of the tibetan plateau with high quaternary activity and frequent historic earthquakes large landslides along the fault zone have caused substantial damage and are the second most important regional hazard after earthquakes a landslide inventory in a 7339 km2 area along the xsf zone documented 415 landslides and evaluated landslide distribution characteristics using frequency ratio fr and weight of evidence woe models to map landslide susceptibility a total of 11 variables were analyzed as input variables slope angle slope aspect altitude planform curvature topographic wetness index distance from active faults lithology annual rainfall distance from rivers distance from roads and the ndvi of the study area among these factors the distance from active faults altitude slope angle aspect lithology and rainfall were the dominant influencing factors assessment of six susceptibility mapping schemes with fr and woe models using the roc method showed that while all six of the model schemes produced good results on the whole the fr model performed better than the woe model the landslide susceptibility map of the fr model with six variables performed as well as the woe model with the full 11 variables inclusion of more variables did not necessarily translate into a better predictive capability several factors typically associated with susceptibility to rainfall triggered landslides topographic convergence rainfall and topographic wetness index either did not follow expected patterns rainfall or were not good general predictors of landslide locations topographic convergence and wetness index in contrast distance to active faults slope aspect and topographic divergence were the best predictors as measured by the fr method this combination points to earthquakes rather than rainfall as the dominant landslide triggering mechanism in the study area

improving landslide susceptibility mapping using morphometric features in the mawat area kurdistan region ne iraq comparison of different statistical models abstract susceptibility mapping provides information about vulnerable locations and thus helps to potentially decrease infrastructure damage due to mass wasting during the past decades expansion of settlements into areas prone to landslides in iraq has highlighted the importance of accurate landslide susceptibility studies the main goal of this research is to implement selected morphometric parameters to improve prediction of landslide susceptibility in the zagros mountain region we used the mawat area in the kurdistan region ne iraq to test the added value of morphometric indicators sixteen morphometric factors mainly derived from a digital elevation model dem extracted using the stereo ability of the advanced spaceborne thermal emission and reflection radiometer aster satellite as well as geological and environmental predictive factors were appraised we evaluated and compared frequency ratio fr weight of evidence woe logistic regression lr and probit regression pr approaches in combination with morphometric indices to determine the landslide susceptibility ls the areas under the curve auc of the prediction rate curve prc relative landslide density index r index and true positive percentage tpp for the four models show that all models perform similarly and the focus should be on careful selection of the predictive factors which is far more important than the methods used results indicate that lithology and slope aspects are the more dominant factors that lead to detect possible occurrence of landslides furthermore this work demonstrates that the hypsometric integral performs better than the commonly used slope curvature as a predictor and thus increases the prediction accuracy of the susceptibility map we argue that the use of adequate morphometric parameters can increase the efficiency of the ls mapping in other regions of the world

landslide susceptibility assessment in lianhua county china a comparison between a random forest data mining technique and bivariate and multivariate statistical models abstract landslides are an important natural hazard that causes a great amount of damage around the world every year especially during the rainy season the lianhua area is located in the middle of china s southern mountainous area west of jiangxi province and is known to be an area prone to landslides the aim of this study was to evaluate and compare landslide susceptibility maps produced using the random forest rf data mining technique with those produced by bivariate evidential belief function and frequency ratio and multivariate logistic regression statistical models for lianhua county china first a landslide inventory map was prepared using aerial photograph interpretation satellite images and extensive field surveys in total 163 landslide events were recognized in the study area with 114 landslides 70 used for training and 49 landslides 30 used for validation next the landslide conditioning factors including the slope angle altitude slope aspect topographic wetness index twi slope length ls plan curvature profile curvature distance to rivers distance to faults distance to roads annual precipitation land use normalized difference vegetation index ndvi and lithology were derived from the spatial database finally the landslide susceptibility maps of lianhua county were generated in arcgis 10 1 based on the random forest rf evidential belief function ebf frequency ratio fr and logistic regression lr approaches and were validated using a receiver operating characteristic roc curve the roc plot assessment results showed that for landslide susceptibility maps produced using the ebf fr lr and rf models the area under the curve auc values were 0 8122 0 8134 0 7751 and 0 7172 respectively therefore we can conclude that all four models have an auc of more than 0 70 and can be used in landslide susceptibility mapping in the study area meanwhile the ebf and fr models had the best performance for lianhua county china thus the resultant susceptibility maps will be useful for land use planning and hazard mitigation aims

discovery of the late triassic middle carnian rhaetian radiolarians in the volcano sedimentary sequences of the kocali complex se turkey correlation with the other tauride units abstract the kocali complex in se turkey includes pelagic sediments pelagic limestones cherts etc basic volcanic rocks of oceanic crust origin together with platform derived sediments its depositional age was previously assigned as late jurassic early cretaceous in order to study the radiolarian contents of volcano sedimentary sequences in this complex six stratigraphic sections have been measured mainly at the ne and nw adiyaman city radiolarian faunas from these stratigraphic sections reveal that the age of these sequences ranges from middle carnian to rhaetian based on these data the depositional age of the complex is older than the previously assigned lithological characteristics widespread triassic basic volcanic rocks associated with pelagic sediments and radiolarian contents of these sequences have close similarities with the sequences of the alakircay nappe of the antalya nappes in western and central taurides based on taxonomic studies 99 taxa have been determined of which one genus adiyamanium and four species monocapnuchosphaera kocaliensis paronaella speciosa ferresium okuyucui and adiyamanium crassum are described as new

cross application used to validate landslide susceptibility maps using a probabilistic model from korea a study of landslides in youngin janghung and boeun korea using the geographic information system gis validates a spatial probabilistic model for landslide susceptibility analysis locations were identified from aerial photographs satellite images and field surveys topography soil type forest cover and land cover maps were constructed from spatial data sets landslide occurrence is influenced by 13 factors evidence for which was extracted from the database with the frequency ratio of each factor computed landslide susceptibility maps use frequency ratios derived not only from data for each area but also ratios one from the probabilistic model calculated from the other two areas nine maps in all as a cross check of method validity for validation analytical results were compared in each study area with actual landslide locations boeun based on its frequency ratio showed the best accuracy 82 49 whereas janghung based on the boeun frequency ratio showed the worst 69 53

estimating shallow subsidence in microtidal salt marshes of the southeastern united states kaye and barghoorn revisited abstract simultaneous measurements of vertical accretion and change in surface elevation relative to a shallow 3 5 m subsurface datum were made in selected coastal salt marshes of louisiana florida and north carolina to quantitatively test kaye and barghoorn s contention that vertical accretion is not a good surrogate for surface elevation change because of autocompaction of the substrate rates of subsidence of the upper 3 5 m of marsh substrate were calculated for each marsh as the difference between vertical accretion and elevation change measured with feldspar marker horizons and a sedimentation erosion table surface elevation change was significantly lower than vertical accretion at each site after 2 years indicating a significant amount of shallow subsidence had occurred ranging from 0 45 to 4 90 cm the highest rate of shallow subsidence occurred in the mississippi delta results confirm kaye and barghoorn s contention that vertical accretion is not generally a good surrogate for elevation change because of processes occurring in the upper few meters of the substrate including not only compaction but also apparently shrink swell from water storage and or plant production decomposition at some sites indeed surface elevation change was completely decoupled from vertical accretion at the florida site the assumption of a 1 1 relationship between vertical accretion and surface elevation change is too simplistic a generalization of the complex interactions between accretionary and substrate processes consequently the potential for coastal marsh submergence should be expressed as an elevation deficit based on direct measures of surface elevation change rather than accretion deficits these findings also indicate the need for greater understanding of the influence of subsurface and small scale hydrologic processes on marsh surface elevation

landslide susceptibility assessment using weights of evidence applied to a study area at the jurassic escarpment sw germany a gis based model for the assessment of the landslide susceptibility in a selected area of the jurassic escarpment in the swabian alb sw germany is described using the weights of evidence method a quantitative model applied to landslides and their causative factors was created and illustrated in susceptibility maps while previous research work in this area concentrated on large scale investigations the present study was carried out at a regional level with a target scale of 1 150 000 the method is based on the assumption that future landslides will occur under the conditions similar or equal to those of past comparable landslides of the same type therefore the analysis was limited to one single type of landslides where the causative factors can be assumed as stable over a period of time due to uncertainties in the model mainly because of variances of the weights assigned to the causative factors the derived probability values representing the susceptibility for future landslides have to be considered relative however potential susceptible areas can be delineated and landslide indicators can be identified from the available data set slopes with angles from 11 to 26 composed of the oxford limestone marls as well as strongly argillaceous and silty colluvial material such as solifluction layers and colluvial cones are susceptible the main soil type of the escarpment and the other steep slopes of the swabian alb valleys are rendzinas formed in solifluction layers rendzina profiles including rock debris and clay which are superimposed on marl debris were also identified as landslide indicators these findings are in agreement with previous geomorphological studies in the same area the methodology seems to have widespread applicability beyond this local research area with the limitation that the knowledge of past landslides input to the model affects the absolute value of the final probability

origin and emplacement of the late cretaceous baer bassit ophiolite and its metamorphic sole in nw syria abstract the baer bassit ophiolite of inferred late cretaceous age was emplaced from the south tethys ocean onto the leading edge of the arabian continental margin in latest cretaceous maastrichtian time dismembered sequences in different thrust sheets can be correlated to produce a complete ophiolite sequence with a metamorphic sole at the base overlain in turn by upper mantle tectonite rare cumulates massive and layered gabbros localized high level plagiogranites sheeted dykes basic extrusives and minor fe mn sediments umbers the restored ophiolite sequence is similar to that of the more intact troodos and hatay ophiolites but dissimilar to oman the baer bassit extrusives are magnesian and strongly depleted comparable to primitive island arc tholeiites and some boninitic lavas which favours a subduction related origin a well developed metamorphic sole is divisible into high grade amphibolite facies assemblages in the north and lower grade greenschist facies assemblages in the centre of the region but no complete inverted metamorphic gradient is preserved in any one local area the protoliths of both the high grade amphibolites and lower grade rocks greenschists are interpreted as alkali basalts and pelagic sediments including chert similar to the volcanic rocks in an underlying unmetamorphosed melange the metamorphic fabrics progressively evolved from ductile to brittle during tectonic transport towards the southeast most of the metamorphic fabrics evolved during intense shearing but some of the alkaline metabasites apparently were metamorphosed under relatively static strain conditions the apparent absence of preserved inverted metamorphic gradients in baer bassit may reflect a complex deformation history during emplacement alternatively differing p t conditions may be recorded at different depths at the base of the over riding mantle wedge during emplacement the front of the ophiolite was tectonically imbricated and overthrust by the main ultramafic slab bassit massif the thickest massif baer is underlain by a high grade metamorphic sole and was internally shortened but without thrust duplication of the entire ophiolite sequence following covering by late maastrichtian palaeogene marine calcareous sediments the area was subjected to mid tertiary regional folding this was followed by neogene dominantly left lateral strike slip deformation along the african eurasian plate boundary extending from south of cyprus to the dead sea transform fault as a result the originally emplaced thrust sheets were dissected into three main composite units baer bassit and the southeastern units separated by strongly faulted and sheared ophiolitic blocks and unmetamorphosed volcanic sedimentary melange

susceptibility assessments of shallow earthflows triggered by heavy rainfall at three catchments by logistic regression analyses abstract sometimes regional meteorological anomalies trigger different types of mass movements in may 1998 the western black sea region of turkey experienced such a meteorological anomaly numerous residential and agricultural areas and engineering lifelines were buried under the flood waters besides the reactivation of many previously delineated landslides thousands of small scale landslides mostly the earthflow type occurred all over the region the earthflows were mainly developed in flysch type units which have already presented high landslide concentrations in this study three different catchments namely agustu egerci and kelemen were selected because they have the most landslide prone geological units of the region the purposes of the present study are to put forward the spatial distributions of the shallow earthflows triggered to describe the possible factors conditioning the earthflows and to produce the shallow earthflow susceptibility maps of the three catchments the unique condition units ucu were employed during the production of susceptibility maps and during statistical analyses the unique condition units numbered 4052 for the agustu catchment 13 241 for the egerci catchment and 12 314 for the kelemen catchment the earthflow intensity is the highest in the agustu catchment 0 038 flow ucu and lowest in the egerci catchment 0 0035 flow ucu logistic regression analyses were also employed however during the analyses some difficulties were encountered to overcome the difficulties a series of sensitivity analyses were performed based on some decision rules introduced in the present study considering the decision rules the proper ratios of ucu free from earthflow 0 ucu including the earthflow 1 for the agustu egerci and kelemen catchments were obtained as 3 6 and 5 respectively also a chart for the proper ratio selection was developed the regression equations from the selected ratios were then applied to the entire catchment and the earthflow susceptibility maps were produced the landslide susceptibility maps revealed that 15 of the agustu catchment 8 of the egerci catchment and 7 of the kelemen catchment have very high earthflow susceptibility and most of the earthflows triggered by the may 1998 meteorological event were found in the very high susceptibility zones

autocompaction of shallow silty salt marsh clay abstract empirically derived algorithms are suggested by means of which it is possible to evaluate relations between physical properties in silty salt marsh clay a relation between loss on ignition sand content and bulk dry density in the topmost 5 cm was found to explain 84 of the variation of the latter the bulk dry density in the topmost 0 5 m was found to vary as a logarithmic function of depth below the surface controlled by two constants directly dependent on the bulk dry density in the topmost 5 cm integration of this function illustrates that mass depth msd z down core can be directly related to the bulk dry density of the surface layer for sediments with a surface bulk dry density between 400 kg m 3 and 800 kg m 3 the porosity was found to vary 10 with msd z as another logarithmic function the results allow for an evaluation of the use of marker horizons in the topmost layers right after such a layer has been spread on the surface sedimentation measured in length per time accretion will be significantly larger than for subsequent periods using marker horizons it is therefore not trivial to know the level of the marker as deeper located markers will indicate successively smaller accretion rates with the same sediment input

present and near future global sea level changes abstract values between 1 0 and 1 5 mm yr often quoted in the literature for the present day rate of eustatic sea level rise have been obtained in many cases by averaging records of tide gauge stations after having omitted areas of glacio isostatic or tectonic uplift though including areas of subsidence this approach results in an overestimation of the sea level rise which is increased by the fact that for geological reasons and human induced factors subsidence is expected to occur more frequently than uplift in oceanic and coastal areas in the absence of absolutely stable areas in the world a new approach is proposed which shows that on the atlantic coasts of europe when land movements are removed the sea level rise during the last century has been only 4 6 cm i e two to three times smaller than the estimation claimed by most authors this value is consitent with current computations of the recent effects on sea level of the thermal expansion of the ocean water 2 5 cm and of the melting of small glaciers 1 4 5 cm estimations of possible sea level changes during the next century diverge with different authors varying from a sea level drop of 7 cm to a sea level rise of over 3 5 m there are some problems however with the assumptions made and some feedback phenomena have not yet been taken into account in addition the relationship between the atmospheric co2 content temperature and sea level is far from being demonstrated for the recent past

biophysical controls on accretion and elevation change in caribbean mangrove ecosystems abstract habitat stability of coastal ecosystems such as marshes and mangroves depends on maintenance of soil elevations relative to sea level many such systems are characterized by limited mineral sedimentation and or rapid subsidence and are consequently dependent upon accumulation of organic matter to maintain elevations however little field information exists regarding the contribution of specific biological processes to vertical accretion and elevation change this study used biogenic mangrove systems in carbonate settings in belize bz and southwest florida fl to examine biophysical controls on elevation change rates of elevation change vertical accretion benthic mat formation and belowground root accumulation were measured in fringe basin scrub and dwarf forest types plus a restored forest elevation change rates mm yr 1 measured with surface elevation tables varied widely bz dwarf 3 7 bz scrub 1 1 fl fringe 0 6 fl basin 2 1 bz fringe 4 1 and fl restored 9 9 root mass accumulation varied across sites 82 739 g m 2 yr 1 and was positively correlated with elevation change root volumetric contribution to vertical change mm yr 1 was lowest in bz dwarf 1 2 and fl fringe 2 4 intermediate in fl basin 4 1 and bz scrub 4 3 and highest in bz fringe 8 8 and fl restored 11 8 sites surface growth of turf forming algae microbial mats or accumulation of leaf litter and detritus also made significant contributions to vertical accretion turf algal mats in fringe and scrub forests accreted faster 2 7 mm yr 1 than leaf litter mats in basin forests 1 9 mm yr 1 but similarly to microbial mats in dwarf forests 2 1 mm yr 1 surface accretion of mineral material accounted for only 0 2 3 3 of total vertical change those sites with high root contributions and or rapid growth of living mats exhibited an elevation surplus 2 to 8 mm yr 1 whereas those with low root inputs and low or non living mat accumulation showed an elevation deficit 1 to 5 7 mm yr 1 this study indicates that biotic processes of root production and benthic mat formation are important controls on accretion and elevation change in mangrove ecosystems common to the caribbean region quantification of specific biological controls on elevation provides better insight into how sustainability of such systems might be influenced by global e g climate atmospheric co2 and local e g nutrients disturbance factors affecting organic matter accumulation in addition to relative sea level rise

vegetation change and surface elevation dynamics in estuarine wetlands of southeast australia vertical accretion and surface elevation trends were studied in mangrove and saltmarsh wetlands in southeast australia a total of 69 surface elevation tables each associated with three feldspar marker horizons was deployed in 10 wetlands across 7 estuaries and monitored for three years saltmarsh and mangrove vegetation distributions were mapped for the same estuaries and elevation characteristics of the wetlands were modelled rates of vertical accretion were found to correlate with tidal range no relationship was found between rates of vertical accretion and surface elevation increase a positive relationship was demonstrated between contemporary rates of saltmarsh surface elevation change and longer term rates of mangrove encroachment into saltmarsh we conclude that landward mangrove encroachment may be facilitated by local factors contributing to saltmarsh compaction during drought conditions

random forests and evidential belief function based landslide susceptibility assessment in western mazandaran province iran in many parts of the world landslide susceptibility remains inadequately mapped due to the lack of both data and suitable methods for widespread implementation iran is one of those countries with extensive landslide problems with nearly 4900 large landslides occurring between 1993 and 2007 at the same time landslide susceptibility has not been assessed for the country random forest rf has recently been shown to be a suitable tool for such mapping in this study we further coupled the rf method with an evidential belief function ebf approach and tested the suitability for landslide susceptibility mapping for variable terrain and data conditions in the west of mazandaran province northern iran locations of earlier landslides were identified by interpreting aerial photographs and through extensive field surveys eleven conditioning factors were used in the rf model the spatial relationship between landslide occurrence and conditioning factors was then assessed using the data driven ebf model and ebf values paired to each map finally the ebf maps were used for running the rf model finally the efficiency of the rf ebf model was tested using the area under the curve to measure the success and prediction rates of the incorporated data this resulted in a success rate of 85 2 and a prediction rate of 81 8 the most important conditioning factors identified were lithology altitude distance from roads and land use respectively based on the overall assessment the combined rf and ebf approach was found to be objective and an applicable estimator that improves the predictive accuracy and controls for overfitting and thus useful for landslide susceptibility mapping at regional scales

gis based landslide susceptibility for arsin yomra trabzon north turkey region the purpose of this study is to assess the susceptibility of landslides around yomra and arsin towns near trabzon in northeast of turkey using a geographical information system gis landslide inventory of the area was made by detailed field surveys and the analyses of the topographical map the landslide triggering factors are considered to be slope angle slope aspect distance from drainage distance from roads and the weathered lithological units which were called as geotechnical units in the study idrisi and arcgis packages manipulated all the collected data logistic regression lr and weighted linear combination wlc statistical methods were used to create a landslide susceptibility map for the study area the results were assessed within the scope of two different points a effectiveness of the methods used and b effectiveness of the environmental casual parameters influencing the landslides the results showed that the wlc model is more suitable than the lr model regarding the casual parameters geotechnical units and slopes were found to be the most important variables for estimating the landslide susceptibility in the study area

new evidence and model on the evolution of the southeast anatolian orogen this paper describes the orogenic evolution of the southeast anatolian orogenic belt based mostly on new geologic data collected from its constituent tectonic units in the course of new mapping programs of the past decade the southeast anatolian orogenic segment of the alpides may be divided into three approximately east west trending zones from south to north they are the arabian platform followed by a zone of imbrication and then a zone of nappes the arabian platform includes a mostly marine sedimentary succession deposited from early cambrian to middle miocene time the zone of imbrication is a narrow belt sandwiched between the arabian platform and the zone of nappes it consists of imbricated thrust slices emplaced onto a late cretaceous to early miocene sequence the zone of nappes is the highest tectonic unit consisting of two stacks of nappes simply designated the lower and upper nappes the lower nappe is represented by the slices of a polyphase metamorpbic ophiolitic assemblage and the maden group the upper nappe rests on the lower nappe and is represented by the bitlis and poturge metamorphic massifs southeastern anatolia underwent two major episodes of alpide deformation the first occurred during the late cretaceous period when ophiolite was emplaced on the arabian platform this event was not the consequence of a continental collision the ophiolite obduction onto the arabian platform was followed by a regionwide extension and a new marine transgression over the platform immediately after the ophiolite obduction the second episode of deformation occurred during middle eocene miocene time in two distinct stages as a result of the progressive elimination and complete closure of the ocean s which led to the collision between the zone of nappes located to the north being a part of eurasia and the arabian plate the maden marginal basin formed north of the subduction zone that eliminated the ocean between eurasia and arabia along the southern margin of the taurus belt and abutted the arabian plate much later during the final collision the second episode of deformation formed the present orogenic segment leading to the amalgamation of different tectonic units these amalgamated nappes collided with the arabian plate and welded onto it at the latest stage of the orogenic evolution during the miocene epoch

delineation of landslide hazard areas on penang island malaysia by using frequency ratio logistic regression and artificial neural network models this paper summarizes findings of landslide hazard analysis on penang island malaysia using frequency ratio logistic regression and artificial neural network models with the aid of gis tools and remote sensing data landslide locations were identified and an inventory map was constructed by trained geomorphologists using photo interpretation from archived aerial photographs supported by field surveys a spot 5 satellite pan sharpened image acquired in january 2005 was used for land cover classification supported by a topographic map the above digitally processed images were subsequently combined in a gis with ancillary data for example topographical slope aspect curvature drainage geological litho types and lineaments soil types and normalized difference vegetation index ndvi data and used to construct a spatial database using gis and image processing three landslide hazard maps were constructed on the basis of landslide inventories and thematic layers using frequency ratio logistic regression and artificial neural network models further each thematic layer s weight was determined by the back propagation training method and landslide hazard indices were calculated using the trained back propagation weights the results of the analysis were verified and compared using the landslide location data and the accuracy observed was 86 41 89 59 and 83 55 for frequency ratio logistic regression and artificial neural network models respectively on the basis of the higher percentages of landslide bodies predicted in very highly hazardous and highly hazardous zones the results obtained by use of the logistic regression model were slightly more accurate than those from the other models used for landslide hazard analysis the results from the neural network model suggest the effect of topographic slope is the highest and most important factor with weightage value 1 0 which is more than twice that of the other factors followed by the ndvi 0 52 and then precipitation 0 42 further the results revealed that distance from lineament has the lowest weightage with a value of 0 this shows that in the study area fault lines and structural features do not contribute much to landslide triggering

landslide susceptibility assessment in mountainous area a case study of sichuan tibet railway china in the southeastern tibetan plateau with complex geological conditions the frequent and disastrous geological hazards have posed a severe challenge to the construction and operation safety of the planning sichuan tibet railway based on the remote sensing and field investigation the detailed landslide inventory of jiacha langxian segment of sichuan tibet railway was established after analyzing the general development characteristics of landslides a total of seven causative variables were selected as input parameters to evaluate landslide susceptibility using the weight of the evidence model combined with the probability prediction map and field validation the landslide susceptibility was classified into four categories very high high moderate and low susceptibility based on the landslide susceptibility assessment map the very high and high susceptibility zones are mainly distributed on the both sides of the yarlung zangbo river and its tributaries and the moderate and low susceptibility zones are located 5 km north to the river considering the terrain and landslide disaster prone situation in this region the planning railway line in tunnel on the north bank of the yarlung zangbo river is considered to be reasonable as for the subgrade and bridge section of the railway especially for tunnel entrance necessary slope reinforcement should be carried out considering the objective safety threat from landslides to the railway we hold the opinion that it is necessary to compare the scheme of changing route and taking engineering protection measures in the langzhen langxian segment

mapping landslide susceptibility with frequency ratio statistical index and weights of evidence models a case study in northern iran the main objective of this study is to investigate potential application of frequency ratio fr weights of evidence woe and statistical index si models for landslide susceptibility mapping in a part of mazandaran province iran first a landslide inventory map was constructed from various sources the landslide inventory map was then randomly divided in a ratio of 70 30 for training and validation of the models respectively second 13 landslide conditioning factors including slope degree slope aspect altitude plan curvature stream power index topographic wetness index sediment transport index topographic roughness index lithology distance from streams faults roads and land use type were prepared and the relationships between these factors and the landslide inventory map were extracted by using the mentioned models subsequently the multi class weighted factors were used to generate landslide susceptibility maps finally the susceptibility maps were verified and compared using several methods including receiver operating characteristic curve with the areas under the curve auc landslide density and spatially agreed area analyses the success rate curve showed that the auc for fr woe and si models was 81 51 79 43 and 81 27 respectively the prediction rate curve demonstrated that the auc achieved by the three models was 80 44 77 94 and 79 55 respectively although the sensitivity analysis using the fr model revealed that the modeling process was sensitive to input factors the accuracy results suggest that the three models used in this study can be effective approaches for landslide susceptibility mapping in mazandaran province and the resultant susceptibility maps are trustworthy for hazard mitigation strategies

delineation of potential exploration targets based on 3d geological modeling a case study from the laoangou pb zn ag polymetallic ore deposit china abstract the laoangou pb zn ag polymetallic ore deposit lag is a hydrothermal vein type deposit in the east qinling polymetallic metallogenic belt which is controlled by nw ne and nearly sn trending faults and mainly hosted in the dolomite marble of meiyaogou and baishugou formations within the luanchuan ore district lod although district scale metallogenic prediction related to the pb zn ag deposits in the lod has been attempted there have been no studies to formulate a detailed deposit scale metallogenic prediction of the pb zn ag deposit in 3d space here we selected the lag to formulate a metallogenic prediction model for pb zn ag deposit based on data from 1 10 000 scale geological map and 66 boreholes and 39 sections of exploration lines on 1 1000 scale to extract the salient spatial features of the deposit we apply ordinary weights and weighted weights of evidence followed by boosted weights of evidence logistic regression and information entropy for integrating the features of the ore deposit for exploration targeting the c v fractal method is applied to classify the probabilities accordingly three levels of exploration targets are delineated the first level targets are mainly distributed in the periphery of known orebodies m2 m3 ii 3 and vi which are also located in the ore controlling strata and fault zones the second level targets are located in the region of known orebodies indirectly confirming that the prediction result is reliable and the third level targets which are mainly located at the contact between ore controlling strata and metagabbro bodies offer new targets for exploration in this ore district combining our results obtained in this study with those in previous studies we provide some guidelines for exploration targets in the pb zn ag deposits in the lod which might help in more effectively delineating the target zones

landslide susceptibility mapping using index of entropy and conditional probability models in gis safarood basin iran abstract landslide susceptibility mapping is essential for land use planning and decision making especially in the mountainous areas the main objective of this study is to produce landslide susceptibility maps at safarood basin iran using two statistical models such as an index of entropy and conditional probability and to compare the obtained results at the first stage landslide locations were identified in the study area by interpretation of aerial photographs and from field investigations of the 153 landslides identified 105 70 locations were used for the landslide susceptibility maps while the remaining 48 30 cases were used for the model validation the landslide conditioning factors such as slope degree slope aspect altitude lithology distance to faults distance to rivers distance to roads topographic wetness index twi stream power index spi slope length ls land use and plan curvature were extracted from the spatial database using these factors landslide susceptibility and weights of each factor were analyzed by index of entropy and conditional probability models finally the roc receiver operating characteristic curves for landslide susceptibility maps were drawn and the areas under the curve auc were calculated the verification results showed that the index of entropy model auc 86 08 performed slightly better than conditional probability auc 82 75 model the produced susceptibility maps can be useful for general land use planning in the safarood basin iran

gis based frequency ratio and index of entropy models to landslide susceptibility mapping daguan china the main goal of this study is to produce landslide susceptibility maps by frequency ratio fr and index of entropy ioe models based on geographic information system gis for the daguan county of yunnan province china at first landslide locations were identified by earlier reports and aerial photographs as well as by carrying out field surveys and a total of 194 landside locations were constructed from various sources then the landslide inventory map was randomly split into a training dataset 70 136 landslide locations for training the fr and ioe models and the remaining 30 58 landslides locations were used for validation purposes fifteen landslide conditioning factors were constructed in gis the susceptibility maps produced using fr and ioe models were divided into five different susceptibility classes such as very low low moderate high and very high finally the validation of landslide susceptibility maps was carried out based on training dataset and the validation data using the area under the curve auc method the success rate curve showed that the area under the curve for fr and ioe models were 0 8191 and 0 8109 accuracy respectively similarly the validation result showed that the prediction accuracy of the two models was 81 75 for fr model and 81 44 for ioe model respectively the maps produced by both models exhibits better satisfactory properties the landslide susceptibility maps may be useful for planning purposes for environmental protection and natural hazard mitigation studies in the near future

metallogenesis on a mesozoic passive continental margin antalya complex southwest turkey abstract a variety of fe mn and trace metal enriched mesozoic pelagic sediments are associated with the tectonically emplaced antalya complex in southwestern turkey palaeotectonic settings represented within the complex comprise a continental platform passing laterally through a mesozoic passive margin into a zone of marginal oceanic crust formed during the early stages of continental separation the origins of the metalliferous sediments are elucidated using mineralogical major trace element and ree data and comparisons with oceanic and ophiolite related sediments late triassic deposition during the initial continental separation was mostly terrigenous including detrital carbonate derived from adjacent reef complexes during the jurassic and early cretaceous the passive margin underwent accumulation of fine grained terrigenous matter and biogenic silica in deep water below the carbonate compensation depth argillaceous mudstones deposited during a regional hiatus at the end of the upper triassic show unusual fe and trace metal enrichment together with a marked positive ce anomaly indicative of slow hydrogenous accumulation the marginal oceanic crustal zone also shows dominantly terrigenous and siliceous biogenic deposition but with the addition of an important hydrothermal component represented by fe mn deposits these occur within and immediately above the upper triassic lavas of the oceanic crust and as intercalations in the overlying lower cretaceous radiolarian chert sequence most of these sediments show strong fe mn fractionation several show a negative ce anomaly implying rapid incorporation of the rees from seawater the upper triassic fe mn deposits associated with the lavas are relatively trace element depleted and record rapid localised precipitation from relatively high temperature hydrothermal solutions by contrast the more manganiferous and trace element enriched metalliferous horizons in the jurassic to lower cretaceous chert sequences represent more dilute low temperature hydrothermal discharge regional comparisons suggest that dominantly manganiferous deposits free of sulphides are characteristic of the early formed mesozoic ocean crust compared with well established spreading axes like the troodos massif cyprus

geology geochemistry and geodynamic implications of the mafic ultramafic rocks from the northern part of the antalya complex sw turkey abstract the antalya complex in the isparta angle area sw turkey includes allochthonous mesozoic rock assemblages occuring as nappe stacks or disrupted tectonic units formed in response to different melange forming processes the allochthonous rock assemblages in the northern part of the antalya complex are mainly characterized by slope basin deposits associated with the late triassic volcanic rocks varying in composition from alkali basalt to fractionated trachyandesite the late jurassic early cretaceous tholeiitic volcanic rocks in composition from basaltic to rhyolitic and morb type volcanic rocks most likely in cretaceous age that spatially associated with olistostromal and subophiolitic tectonic melange whole rock chemistry of the egridir kizil dag peridotites and the isolated diabasic dykes intruding the peridotites the mineral chemistry of the harzburgitic spinels points to depleted residual mantle peridotite character and two tectonic settings supra subduction zone and ocean ridge environments a characteristic feature of forearc setting extensive geological field investigations and previous studies from the antalya complex and the mamonia complex sw cyprus have led to a conclusion that the late triassic alkaline volcanic rocks are associated with continental rift related deposits in the apex of the isparta angle interbedded with thin pelagic limestone layers to the south and overlain by the late triassic reefal limestones and pelagic deposits in the mamonia complex suggesting progressive deepening and widening in ocean basin towards the south during the late triassic time moreover the triassic lavas of the southern part of the isparta angle and the mamonia complex range from wpb type to transitional and morb type suggesting rapid rifting and drifting in the southern part of the antalya ocean giving rise to evolution of northward narrowing wedge shaped ocean basin constrains on the geological and geochemical characteristics of the mesozoic volcanic rocks associated with the allochthonous assemblages between the apex of the isparta angle and the mamonia complex suggest a continental rifting in the isparta angle area that was followed by nearly northward propagated opening and wedge shaped ocean basin evolution with morb type oceanic crust and evolution of supra subduction type ophiolite with forearc affinity within the same ocean basin

a comparative study of dempster shafer and fuzzy models for landslide susceptibility mapping using a gis an experience from zagros mountains sw iran abstract a catchment area at the zagros mountains nw shiraz iran is selected as a test site to comparing the output results of the dempster shafer d s and fuzzy models in landslide hazard mapping lithology slope angle slope aspect land cover and soil depth were considered as landslide causal factors the factor maps were input into a gis and a modified landslide hazard evaluation factor mlhef rating and fuzzy membership functions as well as belief function values were assessed for each class of the factor maps the fuzzy sum product and gamma combination approaches were examined and output maps were assessed based on the known landslides the outputs of fuzzy sum and product combination rules were not reasonable because these approaches classified the area into very high or very low susceptibility zones respectively which were not compatible to the field and factor maps criteria a value of 0 94 yielded the most reliable susceptibility for landslides overlay of the known landslides with the output favorability map showed that the identified landslides were located in the high and very high susceptible zones the output results of the dempster shafer model plausibility belief and uncertainty images were also evaluated based on the known landslides the results of this approach revealed that although it was expected that most of the known landslides correspond the plausibility or the belief map only a few of them supported the case and some landslides were coincided into the disbelief or uncertainty maps it is concluded that in comparison to the fuzzy model the d s model obtains less reliable results for landslide hazard mapping since the belief functions were assigned based on the fuzzy membership functions this might be due to the integration equations used by the model or the number of evidence maps used as input layers

the application of gis based logistic regression for landslide susceptibility mapping in the kakuda yahiko mountains central japan as a first step forward in regional hazard management multivariate statistical analysis in the form of logistic regression was used to produce a landslide susceptibility map in the kakuda yahiko mountains of central japan there are different methods to prepare landslide susceptibility maps the use of logistic regression in this study stemmed not only from the fact that this approach relaxes the strict assumptions required by other multivariate statistical methods but also to demonstrate that it can be combined with bivariate statistical analyses bsa to simplify the interpretation of the model obtained at the end in susceptibility mapping the use of logistic regression is to find the best fitting function to describe the relationship between the presence or absence of landslides dependent variable and a set of independent parameters such as slope angle and lithology here an inventory map of 87 landslides was used to produce a dependent variable which takes a value of 0 for the absence and 1 for the presence of slope failures lithology bed rock slope relationship lineaments slope gradient aspect elevation and road network were taken as independent parameters the effect of each parameter on landslide occurrence was assessed from the corresponding coefficient that appears in the logistic regression function the interpretations of the coefficients showed that road network plays a major role in determining landslide occurrence and distribution among the geomorphological parameters aspect and slope gradient have a more significant contribution than elevation although field observations showed that the latter is a good estimator of the approximate location of slope cuts using a predicted map of probability the study area was classified into five categories of landslide susceptibility extremely low very low low medium and high the medium and high susceptibility zones make up 8 87 of the total study area and involve mid altitude slopes in the eastern part of kakuda mountain and the central and southern parts of yahiko mountain

landslide susceptibility mapping for a part of tectonic kelkit valley eastern black sea region of turkey considering damage to man made structures by natural hazards in turkey landslides are the second most important hazard after earthquakes for this reason a large scale study titled turkish landslide inventory project has been carried out since 1998 during this project some special susceptibility hazard and risk assessments have been performed in this study a landslide susceptibility map of a part of tectonic kelkit valley in the north of central turkey was produced employing binary logistic regression analyses to achieve the most appropriate results some sensitivity analyses were also carried out for this purpose four different data sets were constructed considering conditioning factors used and sampling strategies applied for the training data sets in this study as a consequence of the analyses the most proper outcomes were obtained by using the data set in which continuous topographical parameters and lithological dummy variables were implemented together and 50 of training data set was taken from seed cells at random correct classification percentage and root mean square error rmse values for the validation data for that case were estimated as 84 16 and 0 36 respectively this prediction capability shows that the landslide susceptibility map produced in this research paper can be used for the planning of protective and mitigation measures in the region

evaluation of anfis and lr models for seismic rockfalls susceptibility mapping a case study of firooz abad kojour iran earthquake 2004 seismic rockfall is one of the prevalent geohazards that cause huge losses in the earthquake stricken areas in the present research a model is developed to map susceptibility occurrence probability of seismic rockfalls in a regional scale using logistic regression lr and adaptive neuro fuzzy inference system anfis techniques in this research firooz abad kojour earthquake of 2004 was introduced as the benchmark and the model base the susceptible zones predicted by lr and anfis methods were compared with the database distribution map of seismic rockfalls by which the results revealed a good overlapping between the susceptible zones predicted by the anfis and the field observation of rockfalls triggered by this earthquake besides for the statistical evaluation of results obtained by lr and anfis models the verification parameters with high accuracy such as density ratio dr quality sum qs and receiver operating characteristic curve roc were used by analyzing the susceptibility maps and considering the qs index obtained by lr 21 04184 and anfis 26 75592 it could be found that the qs of anfis is higher than that of lr moreover based on the obtained value of the area under the curve auc from lr 0 972 and anfis 0 984 methods anfis provided a higher accuracy in zonation and susceptibility mapping of rockfalls triggered by firooz abad kojour earthquake of 2004 compared to the lr method

spatial modelling of gully erosion in mazandaran province northern iran abstract gully erosion is one of the most severe environmental problems in large areas of iran the spatial distribution of gully erosion and its susceptibility zonation was studied using different bivariate statistical models such as frequency ratio fr weights of evidence wofe and index of entropy iofe for this purpose 109 gully erosion locations were identified and divided into training 70 and validating 30 datasets effective factors including elevation slope aspect slope degree slope length ls topographical wetness index twi plan curvature profile curvature land use lithology distance from river drainage density and distance from road were selected to develop maps of gully erosion susceptibility the spatial relationship between gully erosion and each effective factor was calculated by the mentioned models the relative operating characteristic roc curve was implemented for evaluating the accuracy of the applied predictive models results indicated that frequency ratio model had better performance 80 4 than the weight of evidence 79 5 and index of entropy 79 models the produced gully erosion susceptibility maps can be helpful to make decisions for soil and water planning and management and finally sustainable development in the valasht watershed

landslide susceptibility mapping using geographically weighted principal component analysis landslide susceptibility mapping lsm documents the extent of probable landslide events in a region to investigate the distribution pattern recurrence and statistics of slope failure and consequent mass movement similar to other analyses of quantitative sources of spatial data lsm sometimes uses principal component analysis pca a form of multivariate statistical analysis this approach helps identify susceptibility by grouping locations or by measuring the variation between groups the present study outlines the principles and examines the capability of the proposed methodology for landslide mapping considers optimized shapes for spatial units estimates an efficient kernel size using alternating least squares als analysis confirmed by cross validation and uses geographically weighted principal component analysis gwpca to calculate landslide susceptibility using a fuzzy gamma operator rmse and pbias statistical estimators were then used to assess operational efficiency of all lsms using fuzzy gamma operators 0 1 to 0 9 roc curves were drawn for the best result for lsm using a landslide inventory containing 82 landslide points with an area under curve of 0 889 the new tools can improve the quality of landslide related analyses including erosion studies and landscape modeling susceptibility and hazard assessments and risk evaluation

landslide susceptibility mapping for a landslide prone area findikli ne of turkey by likelihood frequency ratio and weighted linear combination models landslides are very common natural problems in the black sea region of turkey due to the steep topography improper use of land cover and adverse climatic conditions for landslides in the western part of region many studies have been carried out especially in the last decade for landslide susceptibility mapping using different evaluation methods such as deterministic approach landslide distribution qualitative statistical and distribution free analyses the purpose of this study is to produce landslide susceptibility maps of a landslide prone area findikli district rize located at the eastern part of the black sea region of turkey by likelihood frequency ratio lrm model and weighted linear combination wlc model and to compare the results obtained for this purpose landslide inventory map of the area were prepared for the years of 1983 and 1995 by detailed field surveys and aerial photography studies slope angle slope aspect lithology distance from drainage lines distance from roads and the land cover of the study area are considered as the landslide conditioning parameters the differences between the susceptibility maps derived by the lrm and the wlc models are relatively minor when broad based classifications are taken into account however the wlc map showed more details but the other map produced by lrm model produced weak results the reason for this result is considered to be the fact that the majority of pixels in the lrm map have high values than the wlc derived susceptibility map in order to validate the two susceptibility maps both of them were compared with the landslide inventory map although the landslides do not exist in the very high susceptibility class of the both maps 79 of the landslides fall into the high and very high susceptibility zones of the wlc map while this is 49 for the lrm map this shows that the wlc model exhibited higher performance than the lrm model

late triassic rifting and jurassic cretaceous passive margin development of the southern neotethys evidence from the adiyaman area se turkey evidence of rifting and continental break up to form the s neotethys is found within the volcanic sedimentary kocali complex this is a folded thrust imbricated succession that includes lavas volcaniclastic sediments pelagic carbonates radiolarites and manganiferous deposits interbedded ribbon cherts contain radiolarians of late triassic to late jurassic age the lower part of the succession of mid late triassic age tarasa formation is dominated by enriched mid ocean ridge basalt e morb the overlying late triassic to mid jurassic interval konak formation is characterised by intercalations of ocean island basalt and e morb taking account of structural position the basalts erupted within the outer part of a continent ocean transition zone continental break up probably occurred during the late triassic carnian norian early to mid jurassic lavas and volcaniclastic sediments record volcanism probably after continental break up in addition the karadut complex is a broken formation that is located at a relatively low structural position just above the arabian foreland pelagic carbonates redeposited carbonates and radiolarites predominate radiolarians are dated as early to mid jurassic and late cretaceous in age the pelagic carbonates include planktic foraminifera of late cretaceous age the karadut complex resulted from the accumulation of calcareous gravity flows pelagic carbonate and radiolarites in a relatively proximal base of slope setting after continental break up morb and ophiolitic rocks formed within the s neotethys further north tectonic emplacement onto the arabian platform took place by earliest maastrichtian time regional interpretation is facilitated by comparisons with examples of triassic rifting and continental break up in the eastern mediterranean region and elsewhere

landslide susceptibility mapping by neuro fuzzy approach in a landslide prone area cameron highlands malaysia this paper presents the results of the neuro fuzzy model using remote sensing data and geographic information system for landslide susceptibility analysis in a part of the cameron highlands areas in malaysia landslide locations in the study area were identified by interpreting aerial photographs and satellite images supported by extensive field surveys landsat tm satellite imagery was used to map the vegetation index maps of the topography lineaments normalized difference vegetation index ndvi and land cover were constructed from the spatial data sets eight landslide conditioning factors such as altitude slope gradient curvature distance from the drainage distance from the road lithology distance from the faults and ndvi were extracted from the spatial database these factors were analyzed using a neuro fuzzy model adaptive neuro fuzzy inference system to produce the landslide susceptibility maps during the model development works a total of five landslide susceptibility models were constructed for verification the results of the analyses were then compared with the field verified landslide locations additionally the receiver operating characteristic curves for all landslide susceptibility models were drawn and the area under curve values were calculated landslide locations were used to validate the results of the landslide susceptibility map and the verification results showed a 97 accuracy for model 5 employing all parameters produced in the present study as the landslide conditioning factors the validation results showed a sufficient agreement between the obtained susceptibility map and the existing data on the landslide areas qualitatively the model yields reasonable results which can be used for preliminary land use planning purposes

sediment transport capacity of sheet and rill flow application of unit stream power theory theoretical equations for calculating the unit stream power of both sheet and rill flow were developed and used to predict the sediment transport capacity of such flows independent data sets from three sources representing both finely aggregated clay soils and coarse textured nonaggregated soils sheet rill and composite sheet rill flow systems and a range of slopes were used to test the utility of the method the results were very good and demonstrated the simplicity and robustness of the method for shallow overland flow the best results were obtained when the critical unit stream power at incipient sediment motion was treated as a constant value that was independent of slope the results also suggest that a unique value of critical unit stream power for rill initiation exists that is independent of soil type for noncohesive loams or fine sands and finely aggregated clay soils the sediment transport capacity can be accurately predicted from a knowledge of the physical characteristics of the soil or bed material alone for aggregated clay soils this requires information on the aggregate size distribution and the effects of soil particle size differentiation as flow rates and unit stream powers increase with the transition from sheet to rill flow

landslide susceptibility delineation in the ar rayth area jizan kingdom of saudi arabia using analytical hierarchy process frequency ratio and logistic regression models mountain areas in the southern western corner of the kingdom of saudi arabia ksa frequently suffer from various types of landsides induced by rainstorms and anthropogenic activities to mitigate these problems landslide susceptibility mapping and classification is important to develop quick and safe mitigation or remediation measures and to help the decision making in future planning by identifying the most vulnerable areas this paper summarizes the findings of a landslide susceptibility analysis in the ar rayth area jizan ksa using an analytical hierarchy process ahp frequency ratio fr and logistic regression lr models with the aid of gis tools and remote sensing data the landslide inventory map was prepared according to historical data interpretation of high resolution satellite images geo eye 0 5 m resolution and quickbird 0 6 m resolution topographic maps 1 10 000 and verified by field investigations an inventory map with 253 landslides locations was extracted from many sources the landslide inventory was randomly divided into two datasets 75 for training the models and 25 for validation an enhanced thematic mapper plus 15 m satellite image acquired in 2006 was used for determining the normalized difference vegetation index a contour map 1 10 000 with a 10 m contour interval was converted to digital elevation model 10 m resolution and subsequently converted to slope slope aspect curvature elevation and drainage networks geological data obtained with the help of satellite images were used to prepare lithological units and lineaments roads were digitized from the high resolution image and a rainfall map was prepared from the rainfall gauges distributed throughout the study area all these data were used to construct a spatial database using gis and image processing three landslide susceptibility maps were constructed one on the basis of a heuristic method using an ahp the other two on the basis of landslide inventories and causative factors using fr and lr furthermore each causative factor s weight was determined according to these three models and landslide susceptibility indices were calculated for verification receiver operating characteristic curves were calculated and the areas under the curve auc for success rate are 0 755 0 828 and 0 749 and for prediction rate are 0 708 0 781 and 0 727 for the ahp fr and lr respectively in addition the percentage of existing training landslides data in high and very high zones of the susceptibility maps is of 73 2 85 31 and 88 59 and for the validation landslides data is 73 2 85 31 and 88 59 for the ahp fr and lr respectively the findings indicated that the values of auc are above 0 7 for both success and prediction rate which indicate these three models are suitable for susceptibility analysis also percent of training and validation landslides data of high and very high zones indicate that lr model is more accurate followed by fr model and ahp model

tidal marsh sedimentation and resilience to environmental change exploratory modelling of tidal sea level and sediment supply forcing in predominantly allochthonous systems abstract the existence and function of tidally dominated and predominantly allochthonous marshes are ultimately contingent upon the operation of hydrodynamic and sedimentary processes within constraints imposed by the available accommodation space and sediment supply this paper re interprets published data relating to contemporary vertical marsh growth and sea level rise in the context of the conceptual model relating elevation sedimentation sea level rise sediment supply and tidal range this analysis is supported by numerical mass balance modelling of the equivalent parameter space and of the sensitivity of marsh hydroperiod and sedimentation to sea level and sediment supply forcing the effect of autocompaction on the translation of sedimentation into elevation change is also considered parameter space modelling provides a framework for the interpretation of field data and affords indicative insights into marsh resilience to change it is argued that the assessment of marsh response to external environmental forcing should be based not on empirical comparisons of sedimentation versus sea level rise but on the estimation of sediment supply and the efficiency with which this is depleted by deposition as metrics of marsh resilience this implies a shift towards more intensive process studies aimed at elucidating more fully the linkages between tidal marshes and adjacent estuarine and coastal systems model results also indicate significant variability in marsh sedimentation associated with 18 6 yr tidal modulation and meteorological processes at short term scales such variability further complicates the interpretation of sedimentation or elevation change data obtained from monitoring programmes of short duration longer term monitoring is of value however as a means of identifying important mechanisms of climate and sediment supply forcing that may contribute to the formation and maintenance of marsh sedimentary sequences

the effect of the sampling strategies on the landslide susceptibility mapping by conditional probability and artificial neural networks this study presented herein compares the effect of the sampling strategies by means of landslide inventory on the landslide susceptibility mapping the conditional probability cp and artificial neural networks ann models were applied in sebinkarahisar giresun turkey digital elevation model was first constructed using a geographical information system software and parameter maps affecting the slope stability such as geology faults drainage system topographical elevation slope angle slope aspect topographic wetness index stream power index and normalized difference vegetation index were considered in the last stage of the analyses landslide susceptibility maps were produced applying different sampling strategies such as scarp seed cell and point the maps elaborated were then compared by means of their validations scarp sampling strategy gave the best results than the point whereas the scarp and seed cell methods can be evaluated relatively similar comparison of the landslide susceptibility maps with known landslide locations indicated that the higher accuracy was obtained for ann model using the scarp sampling strategy the results obtained in this study also showed that the cp model can be used as a simple tool in assessment of the landslide susceptibility because input process calculations and output process are very simple and can be readily understood

landslide susceptibility mapping at central zab basin iran a comparison between analytical hierarchy process frequency ratio and logistic regression models abstract the purpose of this study is to compare the landslide susceptibility mapping models of logistic regression lr analytical hierarchy process ahp and frequency ratio fr applied in the central zab basin west azerbaijan iran eight factors were used for landslide susceptibility mapping including slope aspect land cover precipitation lithology and the distance to roads drainage and faults that affect the occurrence of landslides to get more precision speed and facility in our analysis all descriptive and spatial information was entered into gis system satellite images landsat etm and spot 5 are also used to prepare for land use and landslide inventory mapping respectively landslide events as used as dependant variable and data layers as independent variable making use of the correlation between these two variables in landslide susceptibility the three models are validated using the relative landslide density index r index and the receiver operating characteristic roc curves the predictive capability of each model was determined from the area under the relative operating characteristic curve and the areas under the curves obtained using the lr ahp and fr methods are 0 8941 0 8115 and 0 8634 respectively these results indicate that the lr and fr models are relatively good estimators of landslide susceptibility in the study area the interpretations of the susceptibility map reveal that precipitation lithology and slope played major roles in landslide occurrence and distribution in the central zab basin in general all three models were reasonably accurate the resultant maps would be useful for regional spatial planning as well as for land cover planning

probabilistic landslide susceptibility mapping in the lai chau province of vietnam focus on the relationship between tectonic fractures and landslides this study evaluates the susceptibility of landslides in the lai chau province of vietnam using geographic information system gis and remote sensing data to focus on the relationship between tectonic fractures and landslides landslide locations were identified from aerial photographs and field surveys topographic geological data and satellite images were collected processed and constructed into a spatial database using gis data and image processing techniques a scheme of the tectonic fracturing of crust in the lai chau region was established lai chau was identified as a region with many crustal fractures where the grade of tectonic fracture is closely related to landslide occurrence the influencing factors of landslide occurrence were distance from a tectonic fracture slope aspect curvature soil and vegetative land cover landslide prone areas were analyzed and mapped using the landslide occurrence factors employing the probability frequency ratio model the results of the analysis were verified using landslide location data and showed 83 47 prediction accuracy that emphasized a strong relationship between the susceptibility map and the existing landslide location data the results of this study can form a basis stable development and land use planning for the region

constraints on measurement of sea level movements from salt marsh accretion rates the use of sediment accretion rates measured on coastal and estuarine salt marshes as a surrogate for rates of sea level change rests on the usually implicit assumption that marsh maturity is unchanged over the measurement period this assumption is inherently difficult to test empirically but a simple mathematical analysis shows that it is true only in a severely restricted case under most practical conditions measured accretion rates either over estimate or under estimate the rate of sea level change under certain circumstances they may indicate an upward trend when the tendency is actually downward a knowledge of marsh history is critical to the evaluation of such measurements sea level movements estimated from accretion rates are theoretically most reliable in the case of relatively old marshes and comparatively short measurement periods

assessment of fractal dimension and geometrical characteristics of the landslides identified in north of tehran iran the aim of the presented study is to assess the fractal dimension d and the geometrical characteristics length and width of the landslides identified in north of tehran iran at first the landslide locations 528 landslides were identified by interpretation of aerial photographs satellite images and field surveys and then to calculate the fractal dimension d we used the computer programming named as fracek in the next step geometrical characteristics of each landslide such as length l and width w were calculated by arcgis software the landslide polygons were digitized from the mentioned landslide inventory map and rotated based on movement direction the fractal dimension for all landslides varied between 1 665 and 1 968 subsequently the relationship between the length width ratios and theirs fractal d values for 528 landslides was calculated the results showed that correlation coefficients r which are different regression models such as exponential linear logarithmic polynomial and power between d and l w ratio are relatively high respectively 0 75 0 75 0 76 0 78 and 0 75 it can be concluded that the fractal dimension values and geometry characteristics of landslides would be useful indices for the management of hazardous areas susceptible slopes land use planning and landslide hazard mitigation

fine sediment sources and sinks around the east anglian coast uk the cliffs of norfolk and suffolk yield an average of 785 000 tonnes t of fine sediments to the coastal zone annually east anglian rivers yield very little 5500 t a 1 but those of the wash produce about 100 000 t a 1 by contrast the region is dominated by 1 4 l0 6 ta 1 input from cliff erosion in holderness accumulation in vertical accretion alone of the coastal marshes of east anglia the wash north lincolnshire and the humber requires 1 12 10 6 t a 1 of fines progradation around the wash probably accounts for another 1 1 10 6 t a 1 the east anglian area including the wash is thus sufficient to trap over half the regional mud input from flamborough head to the north side of the thames estuary and could take it all depending on assumptions involved in calculation

landslide susceptibility mapping for ayvalik western turkey and its vicinity by multicriteria decision analysis this paper presents the results of geographical information system gis based landslide susceptibility mapping in ayvalik western turkey using multi criteria decision analysis the methodology followed in the study includes data production standardization and analysis stages a landslide inventory of the study area was compiled from aerial photographs satellite image interpretations and detailed field surveys in total 45 landslides were recorded and mapped the areal extent of the landslides is 1 75 km2 the identified landslides are mostly shallow seated and generally exhibit progressive character they are mainly classified as rotational planar and toppling failures in all 51 45 and 4 of the landslides mapped are rotational planar and toppling types respectively morphological geological and land use data were produced using existing topographical and relevant thematic maps in a gis framework the considered landslide conditioning parameters were slope gradient slope aspect lithology weathering state of the rocks stream power index topographical wetness index distance from drainage lineament density and land cover and vegetation density these landslide parameters were standardized in a common data scale by fuzzy membership functions then the degree to which each parameter contributed to landslides was determined using the analytical hierarchy process method and the weight values of these parameters were calculated the weight values obtained were assigned to the corresponding parameters and then the weighted parameters were combined to produce a landslide susceptibility map the results obtained from the susceptibility map were evaluated with the landslide location data to assess the reliability of the map based on the findings obtained in this study it was found that 5 19 of the total area was prone to landsliding due to the existence of highly and completely weathered lithologic units and due to the adverse effects of topography and improper land use

relationships among vertical accretion coastal submergence and erosion in a louisiana gulf coast marsh abstract vertical accretion in a southwest louisiana spartina patens brackish marsh has not kept pace with coastal submergence during the past three decades the rate of accretion determined from 137cs dating and the use of artificial marker horizons averaged 0 8 cm yr 1 whereas coastal submergence obtained from tide gauge data averaged 1 2 cm yr 1 conversion from marsh to open water bodies closely paralleled the increase in coastal submergence if the resulting aggradation deficit continues the marsh will likely complete its transformation to an open bay in less than 40 years in view of recent projections of increasing sea level rise the results presented may foreshadow a more widespread phenomenon

evidence from the kyrenia range cyprus of the northerly active margin of the southern neotethys during late cretaceous early cenozoic time sedimentary geology and planktonic foraminiferal biostratigraphy have shed light on the geological development of the northern active continental margin of the southern neotethys in the kyrenia range following regional triassic rifting a carbonate platform developed during jurassic cretaceous time followed by its regional burial deformation and greenschist facies metamorphism the platform was exhumed by late maastrichtian time and unconformably overlain by locally derived carbonate breccias passing upwards into upper maastrichtian pelagic carbonates in places the pelagic carbonates are interbedded with sandstone turbidites derived from mixed continental basic volcanic neritic carbonate and pelagic lithologies in addition two contrasting volcanogenic sequences are exposed in the western central kyrenia range separated by a low angle tectonic contact the first is a thickening upward sequence of campanian lower maastrichtian pelagic carbonates silicic tuffs silicic lava debris flows and thick bedded to massive rhyolitic lava flows the second sequence comprises two intervals of basaltic extrusive rocks interbedded with pelagic carbonates the basaltic rocks unconformably overlie the metamorphosed carbonate platform whereas no base to the silicic volcanic rocks is exposed additional basaltic lavas are exposed throughout the kyrenia range where they are dated as late maastrichtian and late paleocene middle eocene in age in our proposed tectonic model related to northward subduction of the southern neotethys the kyrenia platform was thrust beneath a larger tauride microcontinental unit to the north and then was rapidly exhumed prior to late maastrichtian time pelagic carbonates and sandstone turbidites of mixed largely continental provenance then accumulated along a deeply submerged continental borderland during late maastrichtian time the silicic and basaltic volcanogenic rocks erupted in adjacent areas and were later tectonically juxtaposed the campanian early maastrichtian silicic volcanism reflects continental margin type arc magmatism in contrast the upper maastrichtian and paleocene middle eocene basaltic volcanic rocks erupted in an extensional or transtensional setting likely to relate to the anticlockwise rotation of the troodos microplate

sediment dynamics and morphological stability of estuarine mangrove swamps in sherbro bay west africa abstract the relationship between the circulation of fine suspensions in a mangrove colonised estuarine complex short term mangrove substrate accretion and medium term mangrove swamp geomorphic evolution was studied in sherbro bay an infilling microtidal to mesotidal embayment in southern sierra leone formed behind holocene sandy beach ridge barriers the estuarine reaches of streams debouching into the bay have relatively high suspension concentrations sc of silts and clays that ranged during the survey period in 1991 from 0 8 to 40 g l 1 in association with the constitution of turbidity maxima 5 50 g l 1 at the interface between freshwater drainage and the saltwater intrusion however the surveyed mangrove swamp plots showed much lower suspension concentrations 0 09 0 6 g l 1 and low albeit minimum rates of accretion 1 1 3 mm a 1 monitored between 1980 and 1989 these low rates are attributed mainly to the short duration of tidal flooding due to a high substrate elevation within the tidal range and to the low settling potential of the very fine grained suspensions circulating over the swamps a comparison of two sets of aerial photographs 1954 1960 and 1976 showed that these swamps and their channel networks are also characterised by a remarkable medium term morphodynamic stability this stability and the low accretion suggest that the swamps and their channel networks are largely in equilibrium with the hydrology notably flooding duration and sediment loads settling out of mud from the turbidity zones contributes to higher accretion rates up to 12 mm a 1 not taking into account the effects of shallow subsidence on parts of the mudflats fronting the mangroves which are flooded for longer periods some of the mud is deposited over sandy channel bars in the main bay channel and the rest exported seaward it is tentatively suggested that an increase in the duration of tidal flooding generated by global sea level rise at the presently predicted rates could lead to higher sedimentation in the mangrove swamps thus enhancing accretion and the chances of mangrove survival

landslide susceptibility assessment in the hoa binh province of vietnam a comparison of the levenberg marquardt and bayesian regularized neural networks abstract this study investigates the potential application of artificial neural networks in landslide susceptibility mapping in the hoa binh province of vietnam a landslide inventory map of the study area was prepared by combining landslide locations investigated through three projects during the last 10 years some recent landslide locations were identified based on spot satellite images field surveys and existing literature the images have a spatial resolution of 2 5 m ten landslide conditioning factors were utilized in the multilayer feed forward neural network analysis slope aspect relief amplitude lithology land use soil type rainfall distance to roads distance to rivers and distance to faults two back propagation training algorithms levenberg marquardt and bayesian regularization were utilized to determine synoptic weights using a training dataset relative importance of each landslide conditioning factor was assessed using the above mentioned synoptic weights the final connection weights obtained in the training phase were applied to the entire study area to produce landslide susceptibility indexes the results were then imported to a gis and landslide susceptibility maps were constructed landslide locations not used in the training phase were used to verify and compare the results of the landslide susceptibility maps finally the two landslide susceptibility maps were validated using the prediction rate method subsequently areas under the prediction curves were assessed the prediction accuracy of landslide susceptibility maps produced by the bayesian regularization neural network and the levenberg marquardt neural network were 90 3 and 86 1 respectively these results indicate that the two models seem to have good predictive capability the bayesian regularization network model appears more robust and efficient than the levenberg marquardt network model for landslide susceptibility mapping

diagenesis and very low grade metamorphism of the antalya unit mineralogical evidence of triassic rifting alanya gazipasa central taurus belt turkey the paleozoic lower mesozoic formations of the antalya unit in southern turkey comprise diagenetic sediments shale mudstone shale siltstone sandstone and scarce spiculite together with very low grade metamorphic lithologies slate metamudstone metasiltstone metasandstone and metalimestone these diagenetic and metamorphic lithologies are dominant in the northern demirtas alanya and southern gazipasa parts of the unit respectively the main minerals of the meta sedimentary rocks are phyllosilicates 2m1 1md 1m illite ia chlorite c v c s i s quartz plagioclase calcite and dolomite the cambrian cretaceous units of the antalya unit differ from the devonian cretaceous northern bolkardagi and aladag units with respect to age lithology and phyllosilicate assemblage but show a considerable similarity to the metamorphic permian triassic mahmutlar nappe of the alanya unit in their phyllosilicate paragenesis although the antalya and precambrian tertiary geyikdagi units seem to have similar lithologies and phyllosilicate associations there are some distinct mineralogical differences such as phyllosilicate polytypes and degree of diagenetic metamorphic alteration ophiolitic fragments olistostromal lithologies phyllosilicate parageneses illite polytype variations anchi epimetamorphic illite crystallinity and relatively low b values suggest that the paleozoic lower mesozoic parts of the antalya unit were metamorphosed in anticlockwise p t t paths in a rifting associated extensional basin the grade of diagenetic metamorphic alteration increases from north to south in the antalya unit related to the higher heat flow due to the southward deepening of the basin vertical diagenetic metamorphic inversion between the lower paleozoic and triassic units is related to higher the heat flux which affected the triassic sediments rather than to thrust tectonics

gis based landslide susceptibility mapping for a part of the north anatolian fault zone between resadiye and koyulhisar turkey abstract in the present study landslide susceptibility assessment for a part of the north anatolian fault zone between resadiye and koyulhisar townships has been determined using index of entropy ioe and frequency ratio fr models within geographical information system the landslide inventory map has been created in the study area altogether 91 landslides were mapped and 63 69 were randomly selected for modelling with the remainder 28 31 used for validating the models the landslide conditioning factors including slope degree aspect elevation distance to faults distance to streams distance to road were selected subsequently landslide susceptibility maps were produced using frequency ratio and index of entropy models for verification the receiver operating characteristic roc curves were drawn and the areas under the curve auc were calculated the verification results showed that fr model auc 75 71 provided slightly better predictions than the ioe auc 75 43 model according to the fr about 32 54 of the study area is located within high to very high susceptibility classes of landslides the interpretation of the susceptibility map indicates that distance to streams distance to road and distance to fault play major roles in landslide occurrence and distribution in the study area the landslide susceptibility maps like the one produced in this study should provide a valuable tool for the use of planners and engineers for reorganizing or planning new road and domestic constructions