using multiple logistic regression and gis technology to predict landslide hazard in northeast kansas usa abstract landslides in the hilly terrain along the kansas and missouri rivers in northeastern kansas have caused millions of dollars in property damage during the last decade to address this problem a statistical method called multiple logistic regression has been used to create a landslide hazard map for atchison kansas and surrounding areas data included digitized geology slopes and landslides manipulated using arcview gis logistic regression relates predictor variables to the occurrence or nonoccurrence of landslides within geographic cells and uses the relationship to produce a map showing the probability of future landslides given local slopes and geologic units results indicated that slope is the most important variable for estimating landslide hazard in the study area geologic units consisting mostly of shale siltstone and sandstone were most susceptible to landslides soil type and aspect ratio were considered but excluded from the final analysis because these variables did not significantly add to the predictive power of the logistic regression soil types were highly correlated with the geologic units and no significant relationships existed between landslides and slope aspect

evaluation of prediction capability of the artificial neural networks for mapping landslide susceptibility in the turbolo river catchment northern calabria italy abstract landslides are one of the most widespread natural hazards that cause damage to both property and life every year and therefore the spatial distribution of the landslide susceptibility is necessary for planning future developmental activities in this paper the artificial neural network ann technique is tested for developing a landslide susceptibility map in turbolo river catchment north calabria south italy landslides were mapped through air photo interpretation and field surveys by identifying both the landslide depletion zones dzs and accumulation zones azs and relevant geo environmental thematic layers pertaining to landslide predisposing factors were generated using air photo interpretation field surveys and geographic information system gis tools ten predisposing factors were related to the occurrence of landslide lithology faults land use drainage network and a series of topographic factors elevation slope aspect plan curvature topographic wetness index twi and stream power index spi in order to evaluate and validate landslide susceptibility the dzs were divided in two groups using a random partition strategy the first group training set was used to prepare the susceptibility map employing a back propagation learning algorithm in the idrisi taiga software the second group testing set was used to validate the landslide susceptibility model using the confusion matrix and the receiver operating characteristic roc curve the susceptibility map was classified into five susceptibility classes very low low moderate high and very high about 46 of the study area falls in high to very high susceptible classes and most of the dzs mapped 87 3 occur in the same classes the validation results showed satisfactory agreement between the susceptibility map and the dzs locations over 85 of the dzs of the validation set are correctly classified falling in high and very high susceptibility areas also the roc curve had shown an area under curve auc value of 0 90 which demonstrates the robustness and good reliability of the landslide susceptibility model according to these results we conclude that the map produced by the artificial neural network is reliable and the methodology applied in the study produced high performance and satisfactory results which may be useful for land planning policy

tidal rhythmites of the marais vernier seine estuary france and their implications for relative sea level the marais vernier located in the upper reaches of the seine river estuary northern france preserves a thick holocene succession of laminated detrital deposits and peats the spectral analysis of one laminated deposit suggests that tidal processes were largely responsible for supplying sediments to this system two periods 16 and 32 laminae per cycle were identified these cycles can be related to either both the synodic neap spring cycle the so called fortnightly cycle and the anomalistic monthly cycle or both the semiannual and annual tidal cycles the recognition of tidal influence on these deposits provides insight into the likelihood of some relative sea level fluctuations previously inferred from these sediments the depositional rates calculated for the laminated deposits based on the recognition of these tidal cycles suggest that the time interval required to deposit the sediments was far shorter than is implied by considering rates based on regional sea level rise alone

reconstruction of the upper cretaceous chalks removed by dissolution during the cenozoic in the western paris basin during the cenozoic in the western paris basin atmospheric weathering of the chalks with flints of the upper cretaceous led to the creation of clay with flints a reconstitution of the chalks lost to dissolution is proposed and is based on the determination of the age of the parent chalks of the clay with flints and the quantification of the thickness of dissolved chalk the chalks affected by weathering range in age from turonian to maastrichtian thus confirming the deposition of calcareous sediments in the western paris basin up to the maastrichtian chalk weathering took place in situ as indicated by the preservation of the stratigraphic succession of the chalk in the clay with flints profiles weathering led to the dissolution of 20 200 m of chalk with regional variations the weathering rate varies between 2 1 and 14 5 m ma

lithologic column of the arkoma drillhole and its relation to the cajon pass deep drillhole the 1795 m arkoma federal 1 26 well 48 5 m from the cajon pass deep drillhole cpddh provides additional lithologic and structural data pertinent to that project basement surface was encountered 158 m deeper than in the cpddh rock units correlate well between the holes the offset persists to 1128 m below this depth both lithologic unit thicknesses and fault zones correlate between holes on subhorizontal projections a combination of previously unrecognized high angle and low angle faults of several ages are required to explain the structures blind low angle faults may be regionally important

the last millennia history of detrital sedimentation in the lower seine valley normandy nw france review post glacial climate changes and sea level fluctuations have strongly influenced n w european environments and sedimentation to these natural events increasing anthropogenic pressure has to be added forest clearance and agricultural development are the main factors responsible for the erosional processes in northwest europe this article analyses holocene sequences of the lower seine valley lsv paris basin to understand better the origin of detrital and terrigenous input and how much humans have contributed to it three main sectors of the lsv are analysed estuarine fluvial and tributaries since neolithic times there are seven erosional phases that can be identified and essentially linked to human pressure terra nova 00 000 000 2010

a procedure for landslide susceptibility zonation by the conditional analysis method numerous methods have been proposed for landslide probability zonation of the landscape by means of a geographic information system gis among the multivariate methods i e those methods which simultaneously take into account all the factors contributing to instability the conditional analysis method applied to a subdivision of the territory into unique condition units is particularly straightforward from a conceptual point of view and particularly suited to the use of a gis in fact working on the principle that future landslides are more likely to occur under those conditions which led to past instability landslide susceptibility is defined by computing the landslide density in correspondence with different combinations of instability factors the conceptual simplicity of this method however does not necessarily imply that it is simple to implement especially as it requires rather complex operations and a high number of gis commands moreover there is the possibility that in order to achieve satisfactory results the procedure has to be repeated a few times changing the factors or modifying the class subdivision to solve this problem we created a shell program which by combining the shell commands the gis geographical research analysis support system grass commands and the gawk language commands carries out the whole procedure automatically this makes the construction of a landslide susceptibility map easy and fast for large areas too and even when a high spatial resolution is adopted as shown by application of the procedure to the parma river basin in the italian northern apennines

autologistic modelling of susceptibility to landsliding in the central apennines italy in previous research a logistic regression of landslide occurrence on several explanatory variables was fitted and used to map landslide susceptibility for a small area in the central apennines italy here the spatial dependence or spatial correlation in the residuals from the fitted regression model was accounted for by inserting an autocovariate into the model the autocovariate was estimated by applying a gibbs sampler to the susceptibilities for neighbouring pixels as in any landslide susceptibility analysis accuracy was difficult to assess because of the requirement for data on future landslides however by comparing the ordinary logistic model to the autologistic model obtained on the same set of data it was possible to assess the influence of the autocovariate the autocovariate rendered the model simpler because several variables lost their significance and were therefore omitted from the model further areas of high landslide susceptibility estimated from the autologistic model were geographically clustered as one would expect and this may be advantageous in terms of i interpreting the model and ii displaying the results to non experts

landslide susceptibility hazard map in southwest sweden using artificial neural network landslides as major geo hazards in sweden adversely impact on nearby environments and socio economics in this paper a landslide susceptibility map using a proposed subdivision approach for a larg

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

investigating transport properties and turbidity dynamics of a karst aquifer using correlation spectral and wavelet analyses in many places throughout the world drinking water is frequently contaminated by turbidity such turbidity however as representative of particle transport can be used as to trace certain features of particle transport properties in order to investigate the relation between particle and dissolved species transport and hydrodynamics in karst systems correlation and spectral analyses were performed on time series of rainfall input signal and water level specific conductance and turbidity output signals at a karst spring system in the chalk aquifer of the lower seine valley france this system is composed of a spring connected to a sinkhole on the chalk plateau where a small creek enters the subsurface the autocorrelation functions for water level and turbidity showed a short memory effect demonstrating the short duration of the influence of flood events on these two parameters whereas specific conductance representing less mineralized storm derived water had a much longer memory effect these results were interpreted as reflecting the rapid reactivity of the spring to rain events with storage of water in the fissured chalk explaining the longer memory effect for specific conductance than for particles energy spectra computed by fast fourier transform of autocorrelation functions showed a strong structure in the output signals whereas the input signal rainfall was random thus allowing assessment and comparison of system behaviour regarding dissolved and solid transport as well as hydraulics cross correlation functions which allow an assessment of impulse response functions confirmed the low inertia of the system for water level and turbidity and the much higher inertia for specific conductance in addition to the main peak two secondary peaks in the cross correlation functions suggest the existence of additional flowpaths that might involve the contribution of other point source recharge and or delayed infiltration through the clayey surficial formation and solution pipes which could act as epikarst analysis using continuous wavelet spectra allowed a better investigation of the rainfall signal structure and highlighted a strong relationship between turbidity and rainfall which could not be deduced from the energy spectra specific spectral components in water level were isolated and a time domain reconstruction using inverse wavelet transform allowed separation of quick flow and slow flow components

influence of paleotopography base level and sedimentation rate on estuarine system response to the holocene sea level rise the example of the marais vernier seine estuary france the response of coastal systems to allogenic forcing factors is of interest to diverse research communities including those interested in global change sequence stratigraphy and modelling quaternary systems are of particular interest because they provide analogues for ancient rock records to understand the processes responsible for the sedimentary evolution of estuarine systems it is necessary to study as many fluvial systems as possible the objective of this review of the sedimentary evolution of a coastal marsh is to describe the influence of glacial paleotopography on the record of climatic and sea level changes the marais vernier located at the interface between the marine and fluvial parts of the estuary is a part of the lower seine valley wetland network which formed after the last glacial maximum previous studies have described the holocene filling which is composed of peat and detrital material deposited following climatic and sea level changes to understand the sedimentary evolution a paleotopographical based on drillings and electromagnetic surveys and a chronological framework based on radiocarbon dates for the southern peat marsh were defined the peat marsh paleotopography has three erosional surfaces the s1 surface is the oldest and also the highest topographically the s2 surface is younger wider and incised below the s1 surface the s3 surface the youngest of the three is narrow and deeply incised radiometric ages were considered on the basis of their geographical position in relation to the s3 surface prior to 7 5 ka cal bp sediments accumulated only above the narrow area described by the s3 surface at a rate of 5 5 mm yr 1 after 7 5 ka cal bp shortly after the flooding of the seine estuary sediments accumulated as peat deposits over the entire peat marsh at a rate of 3 mm yr 1 in response to the sea level rise the paleotopography delimits the area of deposition during the holocene and thus plays a critical role in determining the vertical accretion rate expressed as a thickness prior to 7 5 ka cal bp the vertical accretion rate 5 5 mm yr 1 was less than that observed for the seine estuary 6 8 mm yr 1 however rate of sea level rise and sediment supply which also affects sediment accumulation rates vary in northwestern europe during the holocene therefore although the marais vernier is a good illustration of paleotopographic influence the effects of autocompaction sea level and sediment supply complicate efforts to quantify the degree to which it controls sediment accumulation

predicting gully occurrence at watershed scale comparing topographic indices and multivariate statistical models abstract in this study the ability of five topographic indices to predict the gully trajectories observed in two adjacent watersheds located in sicily italy was evaluated two of these indices named mspi and mtwi as far as we know have never been employed to this aim they were obtained by multiplying the stream power index spi and the topographic wetness index twi respectively by the convergence index ci the predictive ability of the topographic indices was measured by using both cut off independent auc area under the receiver operating characteristic curve and dependent statistics cohen s kappa index sensitivity specificity these statistics were calculated also for 100 mars multivariate adaptive regression splines and 100 lr logistic regression model runs which used as predictors the topographic variables i e contributing area slope steepness plan curvature and convergence index combined into the five indices performance statistics of both topographic indices and statistical models were calculated using 100 random samples of 2 m grid cells which were extracted only from flow concentration lines this was done in order to focus the validation process on where gully erosion is more likely to occur mspi achieved the best predictive skill auc 0 93 0 71 among the topographic indices and exhibited similar and better accuracy than local i e trained and validated in the same watershed and transferred i e trained in one watershed and tested in the other one lr models respectively on the other hand mspi performed similarly to transferred mars runs auc 0 92 0 71 but slightly worse than local mars runs auc 0 95 0 77 based on the results of this experiment it can be inferred that i including ci helps in detecting hollow areas where gullies are more likely to occur and ii mpsi can be a valid alternative to a data driven approach for mapping gully erosion susceptibility in areas where a gully inventory is not available which is necessary to calibrate statistical models

comparison of bivariate and multivariate statistical approaches in landslide susceptibility mapping at a regional scale abstract landslide susceptibility assessment was undertaken for the waikato region new zealand landslide inventory data were extracted from a pre existing database that included few landslides in the region 1 4 of area and is limited in terms of completeness of record and location uncertainty this database is in contrast to those normally used for research which are derived for the research project and are complete and accurate but is representative of those that may exist within government bodies this paper applies statistical methods to derive a meaningful predictive map for planning purposes from such a relatively poorly defined database susceptibility maps for both logistic regression and weights of evidence were derived and evaluated using success prediction and roc curves both statistical methods gave models with fair predictive capacity for validation samples from the original database with areas under roc curves auc of 0 71 to 0 75 an independent set of landslide data compiled from observations made in google earth showed lower overall prediction quality with the logistic regression method giving the best prediction auc 0 71 for this regional assessment categorical data proved a major constraint on the application of logistic regression as the area considered has complex geology and geomorphology as a result the large number of categories required led to a complex and unwieldy statistical model whereas division into fewer categories meant that real variability in the area could not be adequately represented this limited the result to a model with two continuous variables slope and mean monthly rainfall the incomplete record in the database proved of little concern for the logistic regression method as the model was able to generalise landslide locations from the known sites well giving a similar auc value for the original and independent data the same was not true for the weights of evidence method which was not successful at predicting landslides outside those in the original data

near surface attenuation and site effects from comparison of surface and deep borehole recordings abstract near surface attenuation and site effects are investigated using the seismograms of 17 local earthquakes recorded at depths of 0 0 3 1 5 2 5 and 2 9 km in the cajon pass borehole southern california the borehole penetrates 500 m of miocene sandstone and then crystalline granitic basement rock previous estimates of site response have been limited to shallower holes where the surface reflection interferes with the upgoing direct wave and the deepest sensor is not below the severe near surface effects in bedrock spectral ratios of the direct p and s waves for each earthquake between the different recording levels are well modeled with frequency independent q and amplification at the borehole q p 27 8 and q s 21 7 in the upper 2 9 km increasing from q p 26 and q s 15 in the upper 300 m to q p 133 and q s 47 between 1 5 and 3 km one event was also recorded at a surface granite site less than 1 5 km from the wellhead comparison of the 2 9 km recording with that at this granite site gives q p 50 and q s 23 the similarity of these values with those of previous studies at a wide range of sites suggests that q is very low in the near surface independent of rock type near surface amplification appears considerably more site dependent at the wellhead the amplifications at 1 hz of the direct p and s waves are 12 7 and 13 7 respectively these values include the free surface effect and are in reasonable agreement with the impedance contrast from the borehole logs at the granite site amplification of both p and s waves is less than four direct wave amplification at the wellhead is therefore at least three times that of the granite site the spectra of the direct and coda waves of the one earthquake recorded at both the wellhead and granite sites are compared with the corresponding 2 9 km recording coda wave amplification is in good agreement with the direct wave at the rock site but at the borehole the coda wave amplification factor overestimates the direct wave amplification by a factor of 3

gis techniques and statistical models in evaluating landslide hazard geographical information systems gis and numerical cartography may greatly facilitate the development and use of statistical models for the assessment of regional landslide hazard from a small drainage basin located in central italy relevant geological and geomorphological factors were collected and processed by applying gis technology in particular modules were used which both generate high fidelity digital terrain models and automatically partition the terrain into main slope units the resulting information was then analysed by discriminant analysis which enabled landslide hazard and risk to be evaluated in each slope unit although not lacking drawbacks the method proved to be a feasible and cost effective approach to landslide susceptibility assessment and mapping

constraints on the geometries of structures within the sedimentary rocks at the cajon pass scientific drillsite california an analysis of downhole geophysical logs and their relation to surface geological data constrain the structure in the first 700 m of the cajon pass scientific drillhole several angular folds mapped in a small canyon 150 m to the southeast of the drillsite are associated with a steep northeast dipping reverse fault at depth this fault is inferred to cut the scientific drillhole in basement at 700 m and to intercept a nearby oil exploration well arkoma federal 1 26 within the sediments at 350 m the folds mapped at the surface are thought to have developed in late miocene to early pliocene time during the squaw peak thrusting event the inferred reverse fault offsets the sediment basement contact 180 m between the two holes

hydrological responses of the chalk aquifer to the regional climatic signal piezometric variability was investigated using monthly time series from 40 piezometers in different areas across the upper normandy region over the 1968 2009 period the piezometers were classified according to their hydrological behaviour this paper aimed at characterising the dominant modes explaining piezometric variability and at investigating the causes of this variability significant components in the piezometric signals were identified the annual cycle and an interannual mode 4 12 years with different variances for each observation borehole group the influence of the morphostructural organisation of the upper normandy chalk plateau on the modalities of the water level variability in the chalk aquifer was defined the relative contributions and standard deviations of each component found in the signal time series of the groundwater level was estimated the highest values were recorded in the northern study area and clay with flints and aquifer thicknesses influence the transfer on an annual scale while the loess thickness influences the transfer on a multi year scale

prediction of debris avalanches and flows triggered by a tropical storm by using a stochastic approach an application to the events occurred in mocoa colombia on 1 april 2017 abstract landslides are among the most dangerous natural processes debris avalanches and debris flows in particular have often caused casualties and severe damage to infrastructures in a wide range of environments the assessment of susceptibility to these phenomena may help policy makers in mitigating the associated risk and thus it has attracted special attention in the last decades in this experiment we assessed susceptibility to debris avalanche and flow landslides by using a stochastic approach two different modeling techniques were employed i multivariate adaptive regression splines mars and ii logistic regression lr both mars and lr allow for calculating the probability of landslide occurrence by building statistical relationships between a set of environmental variables and the target variable i e presence absence of the landslide event the target variable was extracted from an inventory of debris avalanche and flow landslides which were triggered by the tropical storm that hit the area of mocoa colombia on 1 april 2017 as predictor variables we employed nine terrain attributes derived from a 5 m resolution dem i e elevation slope angle northness eastness upslope slope angle convergence index topographic position index valley depth and topographic wetness index in addition to lithology distance from faults and presence absence of soil creep processes in our experiment we used three different landslide datasets which contain i the highest point of each recognized landslide crown lines dataset lip ii the highest 10 of cells of each landslide area dataset source and iii the entire landslide areas which include initiation and accumulation zones dataset mass in order to evaluate their predictive ability lr and mars models were submitted to k fold spatial cross validation strategy which consists in extracting random training and test subsets from k spatially disjoint sub areas the results of model validation expressed in terms of area under the roc curve auc demonstrate better predictive performance of mars models with respect to lr models for all the three landslide datasets the mean auc values calculated for the datasets lip source and mass of the mars models are 0 776 0 788 and 0 768 respectively whereas auc values of the lr models are 0 748 0 751 and 0 703 respectively model validation also shows that the predictive skill of the models is better when landslide data are sampled from the highest portions of the landslides dataset source maps of susceptibility to debris avalanche and flow landslides for the mocoa area were produced by using both lr and mars and the three landslide datasets the analysis of the distribution of events versus the susceptibility classes of the maps confirm that mars and the dataset source provide the best ability to discriminate between event and non event cells

holocene millennial to centennial carbonate cyclicity recorded in slope sediments of the great bahama bank and its climatic implications a 38 m long sediment core md992201 retrieved from a water depth of 290 m from the leeward margin of the great bahama bank gbb 25 53 49 n 79 16 34 w has been investigated for changes in aragonite content the core covers the mid to late holocene the past 7230 yr sediment lightness l values was used as a proxy for aragonite content based on a high linear correlation r 0 93 between the x ray diffraction derived aragonite content and l values the resulting time resolution of the l values derived aragonite content ranges from 1 yr at the base of the core to 4 yr at the top detailed time series analysis using monte carlo singular spectrum analysis and spectral analysis lomb scargle fourier transform identifies the presence of seven signals with varying amplitudes and wavelengths that could be traced throughout the past 5500 yr during the first 1600 yr of sedimentation the aragonite record is dominated by the initial flooding of the flat topped gbb superimposed on a multimillennial signal related to holocene sea level changes a millennial scale fluctuation and five quasi periodic oscillations were detected 1 3 2 kyr 500 600 yr 380 yr 260 yr 200 yr and 100 yr period comparisons with other proxies e g tree ring 14c 10be and 18o in ice cores provides information on the origin and dynamics of the individual signals the analysis shows that the 200 yr and 100 yr signals can be attributed to solar forcing the 260 yr 380 yr and the 500 600 yr quasi periodic signals are found to be of climatic origin whereas the millennial scale fluctuations remain enigmatic although solar forcing mechanisms seem likely the data show that variability of solar output as well as past oceanographic and atmospheric changes have modulated the mid to late holocene climate which in turn controlled sediment input variations found in the holocene wedge leeward of the gbb although these periplatform sediments have a rather uniform appearance they still contain a large variety of subtle sedimentary variations

analysis of shear waves with respect to splitting near the san andreas fault summary shear wave recordings acquired by vertical seismic profiling in the cajon pass deep scientific drillhole california have been investigated with respect to shear wave splitting using various methods the methods used should enable detection of possible anisotropy induced ai shear wave splitting consistent with a system with hexagonal symmetry and a horizontally oriented axis of symmetry careful investigation of the direct shear waves leads to the conclusion that a1 shear wave splitting consistent with this simple model cannot be observed with the methods applied the lack of such a1 shear wave splitting is probably partly caused by the low difference between the maximum and minimum principal stress in the area which is probably too modest to vertically align cracks and microcracks to any significant degree the propagation and polarization of the shear waves in this area is thus probably more controlled by factors related to the complex geology rather than to the current stress field the lack of detected a1 shear wave splitting does not however imply that the medium is isotropic the polarization diagrams show clear evidence of shear wave splitting which most likely indicates the presence of an anisotropy of higher order

elemental and mineralogical analyses using geochemical logs from the cajon pass scientific drillhole california and their preliminary comparison with core analyses estimates of elemental and mineralogical abundances from geochemical logs are compared to preliminary chemical and modal analyses from cores in the cajon pass scientific drillhole accuracies of log computed weight percent oxide and mineralogy determinations range from 10 to 30

the influence of forest cover on landslide occurrence explored with spatio temporal information abstract multi temporal landslide inventories in widely forested landscapes are scarce and further studies are required to face the challenges of producing reliable inventories in woodland areas an elaboration of valuable empirical relationships between shallow landslides and forest cover based on recent remote sensing data alone is often hampered due to constant land cover changes differing ages of landslides within a landslide inventory and the fact that usage of different data sets for mapping might lead to various systematic mapping biases within this study we attempted to overcome these difficulties in order to explore the effect of forest cover on shallow landslide occurrences thus forest dynamics were examined on the basis of 9 orthophoto series from 1950s to 2015 distinguishing 3 forest classes based on the wood type these classes were furthermore distinguished in 12 subclasses considering stand density and age a multi temporal landslide inventory was compiled for the same period based on the aerial photography 2 airborne lidar imageries 8 field surveys and archive data we derived topographical parameters slope topographical positioning index and convergency index from the digital elevation model for areal correction and accounting for topographical confounders within a logistic regression model empirical relationships were assessed by means of a areal changes of forests and logged areas b spatio temporal distribution of shallow translational landslides c frequency ratios and d logistic regression analysis the findings revealed that forests increased by 16 2 from 1950s to 2015 311 landslides of 351 in total that where mapped in total could be assigned to the observed time series and were considered for our analyses frequency ratios and odds ratios indicated a stabilising effect of all forest classes on landslide occurrences odds ratios observed for the models based on aggregated data sets 3 forest classes indicated provided evidence that forest was constantly estimated to be less prone to slope failure than their non forested counterparts the chances for forest classes to be affected by shallow landslides were estimated to be considerably lower whenever topographic predictors were as well included in the model a detailed inspection of the statistical results suggests that the obtained empirical relationships should be interpreted with care challenges in the mapping procedures of forests and landslides implications of the applied methods and potential pitfalls are discussed

machine learning and fractal theory models for landslide susceptibility mapping case study from the jinsha river basin abstract the quality of non landslide negative samples may result in unreasonable prediction results for machine learning ml models the aim of this study is to improve the performance of ml models by perfecting the quality of non landslide samples in landslide susceptibility modelling so as to produce more reliable susceptibility maps the middle and lower reaches of jinsha river basin mlrjb were chosen as the study area and the elevation slope aspect curvature lithology distance to faults slope of slope slope of aspect precipitation land use and ndvi were considered as predisposing factors for landslide susceptibility mapping firstly three non landslide samples are randomly selected from the low slope area landslide free area and very low susceptibility area based on fractal theory ft model generation and then three sample scenarios are constructed with 4445 landslide positive samples next the performance of cross application of three sample scenarios in the support vector machines svm and naive bayes nb models are compared and evaluated based on the statistical indicators such as accuracy recall precision receiver operating characteristic roc curve and area under the roc curve auc the evaluation results show that the non landslide negative samples generated on the basis of ft model are more reasonable and that the hybrid method supported by ft and ml models exhibits the highest prediction efficiency around 94 overall accuracy produced by scenario ft followed by scenario ss 87 and scenario rs 65 finally with the validation of landslide and unstable slopes data the landslide susceptibility map produced by the hybrid method composed of ft model and the svm model is the ultimate output product for landslide prevention

landslide hazard evaluation a review of current techniques and their application in a multi scale study central italy in recent years growing population and expansion of settlements and life lines over hazardous areas have largely increased the impact of natural disasters both in industrialized and developing countries third world countries have difficulty meeting the high costs of controlling natural hazards through major engineering works and rational land use planning industrialized societies are increasingly reluctant to invest money in structural measures that can reduce natural risks hence the new issue is to implement warning systems and land utilization regulations aimed at minimizing the loss of lives and property without investing in long term costly projects of ground stabilization government and research institutions worldwide have long attempted to assess landslide hazard and risks and to portray its spatial distribution in maps several different methods for assessing landslide hazard were proposed or implemented the reliability of these maps and the criteria behind these hazard evaluations are ill formalized or poorly documented geomorphological information remains largely descriptive and subjective it is hence somewhat unsuitable to engineers policy makers or developers when planning land resources and mitigating the effects of geological hazards in the umbria and marche regions of central italy attempts at testing the proficiency and limitations of multivariate statistical techniques and of different methodologies for dividing the territory into suitable areas for landslide hazard assessment have been completed or are in progress at various scales these experiments showed that despite the operational and conceptual limitations landslide hazard assessment may indeed constitute a suitable cost effective aid to land use planning within this framework engineering geomorphology may play a renewed role in assessing areas at high landslide hazard and helping mitigate the associated risk

holocene evolution of a wetland in the lower seine valley marais vernier france estuaries like that of the seine river in nw europe developed in incised fluvial valleys after the last glacial maximum since the 1940s several authors have studied the largest wetland of the seine estuary the marais vernier to understand depositional environments during holocene infilling we reinterpret previous research based on new and published data for example fill thickness and material source to 1 describe facies and depositional environments 2 reconstruct palaeoenvironmental evolution 3 show the influence of local and global forcing on depositional environments before 7000 6000 cal bc terrestrial material was deposited because of catchment erosion related to changes in climate just before 7000 6000 cal bc estuarine material began to be deposited in low lying areas in response to sea level rise while terrestrial material still settled at higher elevations after this but before 5850 5710 cal bc estuarine material areas began to accumulate at both high and low elevations this marked a general flooding of the marais vernier synchronous with that at the seine estuary mouth soon after peat accumulated over a wide area as a response to a local change in accommodation and a worldwide drop in sea level a tidal channel developed to the west of the marais vernier providing minerogenic material after 1130 900 cal bc human influence becomes increasingly clear in the record this record of regional change during the holocene can serve as a reference for further studies in the area

investigating the effects of different landslide positioning techniques landslide partitioning approaches and presence absence balances on landslide susceptibility mapping the ziarat watershed located in the south of the golestan province iran has witnessed several destructive landslide episodes prompting a number of researchers to aspire to improve landslide susceptibility modeling lsm techniques we constructed three scenarios focusing on landslide positioning techniques pixel based centroid crown and toe training test sampling strategies mahalanobis distance md and random sampling rs with alternative landslide non landslide data balances 1 1 1 2 and 1 3 the data mining boosted regression trees brt model was used for the landslide susceptibility modeling using landslide data and 13 landslide controlling factors for the ziarat watershed the performance of the scenarios was assessed using the areas under the success and prediction rate curves ausrc and auprc a combination of pixel based md 1 2 showed the highest learning capability and goodness of fit with an ausrc value of 0 87 and the highest predictive power and generalization capacity with an auprc value of 0 79 conversely centroid based 1 3 rs crown based 1 3 rs and toe based 1 3 rs performed less well comparatively the pixel based md and 1 2 data balance scenarios surpassed their counterparts and outperformed the other models the results indicated a high spatial differentiation with a significant chi square value of 4549 46 at 95 confidence level moreover 15 21 of the study area containing almost 50 of the landslides was found to have a high susceptibility to landslides according to the premier scenario pixel based md 1 2 lithological formation distance from roads and ndvi with respective contributions of 31 4 12 9 and 12 are the main spatial controlling factors leading to landslide occurrences in the study area

landslide inventory maps new tools for an old problem landslides are present in all continents and play an important role in the evolution of landscapes they also represent a serious hazard in many areas of the world despite their importance we estimate that landslide maps cover less than 1 of the slopes in the landmasses and systematic information on the type abundance and distribution of landslides is lacking preparing landslide maps is important to document the extent of landslide phenomena in a region to investigate the distribution types pattern recurrence and statistics of slope failures to determine landslide susceptibility hazard vulnerability and risk and to study the evolution of landscapes dominated by mass wasting processes conventional methods for the production of landslide maps rely chiefly on the visual interpretation of stereoscopic aerial photography aided by field surveys these methods are time consuming and resource intensive new and emerging techniques based on satellite airborne and terrestrial remote sensing technologies promise to facilitate the production of landslide maps reducing the time and resources required for their compilation and systematic update in this work we first outline the principles for landslide mapping and we review the conventional methods for the preparation of landslide maps including geomorphological event seasonal and multi temporal inventories next we examine recent and new technologies for landslide mapping considering i the exploitation of very high resolution digital elevation models to analyze surface morphology ii the visual interpretation and semi automatic analysis of different types of satellite images including panchromatic multispectral and synthetic aperture radar images and iii tools that facilitate landslide field mapping next we discuss the advantages and the limitations of the new remote sensing data and technology for the production of geomorphological event seasonal and multi temporal inventory maps we conclude by arguing that the new tools will help to improve the quality of landslide maps with positive effects on all derivative products and analyses including erosion studies and landscape modeling susceptibility and hazard assessments and risk evaluations

the neogene and quaternary clay with flints north and south of the english channel comparisons of distribution age genetic processes and geodynamics weathered residual accumulations termed clay with flints argiles a silex overlying cretaceous deposits are widespread in southern england and northwestern france geological and pedological studies and some field surveys indicate their distribution nature age and origin in france the microfaunas preserved in the hollow flints of the clay with flints demonstrate the preservation of the parent chalk stratigraphy in the sections studied i e the clay with flints corresponds to in situ weathering profiles however in england and in france an important part of the clay component is derived from a thin veneer of basal tertiary sediment overlying sub tertiary marine erosion surfaces of various palaeogene transgressions in england as in france the youngest generation of clay with flints can be dated from late pliocene to quaternary it formed after removal of different cenozoic deposits on many plateaus and during the downcutting of pleistocene rivers the most visible effect of subsequent weathering profile development is irregular dissolution of the underlying chalk to produce deep karstic pipes into which the clay with flints has slumped other pedological processes include rubification clay illuviation and cryoturbation clay with flints also provides evidence of quaternary palaeoenvironments cenozoic continental palaeosurfaces and their vertical deformation copyright 2003 john wiley sons ltd

how subsoil morphology and erodibility influence the origin and pattern of late holocene tidal channels case studies from the belgian coastal lowlands abstract this paper aims at a better understanding of the late holocene re entrance of the tidal system in the belgian coastal plain after a 2 3 ka years long period of peat growth the re entrance was associated with the development of deeply incised tidal channels the initial cause of the re entrance still a missing link in the understanding of the late holocene coastal change is investigated by focusing on the specific location of the young tidal channels the research though based in the western belgian coastal plain is relevant to the lowlands of the southern north sea and english channel the investigation combines stratigraphic radiocarbon and sedimentological data together with maps showing the morphology of the pre holocene surface the distribution of the holocene deposits and the erosional surface produced by the late holocene channels it appears that the young channels re occupied the same position as their early and mid holocene predecessors the re entrance of the tidal system began by a removing of the upper part of the older channels which originated from the mainland once the channels were cleaned of sediment tidal waters could re enter and rework the easily erodable sand of the older channels and pleistocene deposits

lithostratigraphy determined from discriminant analysis of geochemical well logs from the cajon pass scientific drillhole california geochemical well logs recorded in the cajon pass scientific drillhole provide an estimate of the elemental concentrations of si al fe ca k th ti s and the hree gd the continuous geochemical profiles were used to define a lithostratigraphy in the cystalline basement from 501 to 1 829 m the interval between the faulted top of basement and a thrust fault at 689 m consists of six alternating slivers of granite and granodiorite interlayered granitic and granodioritic units were then encountered to another fault at 1290 m whereas gneisses of granitic to tonalitic composition were logged in the basal portion of the hole linear discriminant analysis of major element chemistry as well as variations in gd th ti and s were used to demonstrate that each of the major lithostratigraphic units is chemically distinct different trace element signatures and variable degrees of metamorphism indicate a complex thermal and hydrological history for the basement rocks encountered in the cajon pass well

comparing models of debris flow susceptibility in the alpine environment abstract debris flows are widespread in val di fassa trento province eastern italian alps where they constitute one of the most dangerous gravity induced surface processes from a large set of environmental characteristics and a detailed inventory of debris flows we developed five models to predict location of debris flow source areas the models differ in approach statistical vs physically based and type of terrain unit of reference slope unit vs grid cell in the statistical models a mix of several environmental factors classified areas with different debris flow susceptibility however the factors that exert a strong discriminant power reduce to conditions of high slope gradient pasture or no vegetation cover availability of detrital material and active erosional processes since slope and land use are also used in the physically based approach all model results are largely controlled by the same leading variables overlaying susceptibility maps produced by the different methods statistical vs physically based for the same terrain unit of reference grid cell reveals a large difference nearly 25 spatial mismatch the spatial discrepancy exceeds 30 for susceptibility maps generated by the same method discriminant analysis but different terrain units slope unit vs grid cell the size of the terrain unit also led to different susceptibility maps almost 20 spatial mismatch maps based on different statistical tools discriminant analysis vs logistic regression differed least less than 10 hence method and terrain unit proved to be equally important in mapping susceptibility model performance was evaluated from the percentages of terrain units that each model correctly classifies the number of debris flow falling within the area classified as unstable by each model and through the metric of roc curves although all techniques implemented yielded results essentially comparable the discriminant model based on the partition of the study area into small slope units may constitute the most suitable approach to regional debris flow assessment in the alpine environment

middle to upper palaeolithic site formation processes at the bordes fitte rockshelter central france transformation in technological patterns associated with the middle to upper palaeolithic transition between 50 and 40 ka in western europe and their relationship with the neanderthal and anatomically modern human populations and behaviors are issues that continue to stimulate heated debate in this article we use the middle and early upper palaeolithic archaeo stratigraphic record from the bordes fitte rockshelter les roches d abilly site central france a bayesian analysis of the ages obtained by accelerator mass spectrometry radiocarbon on ultrafiltered collagen and by luminescence on quartz and feldspar grains to establish a timeline for material culture and sedimentary dynamic changes during the middle to upper palaeolithic transition technology refitting studies and taphonomy of lithic artifacts recovered in the geoarchaeological field units d1 and d2 permit to characterize 3 reduction strategies levallois discoidal and ch telperronian blade that took place between the cold heinrich events 5 and 4 we discuss the implications of the results to characterize the end of the middle palaeolithic and for distinguishing anthropogenic and non anthropogenic factors in middle to upper palaeolithic assemblage s variability

object based gully feature extraction using high spatial resolution imagery abstract gully erosion is responsible for a substantial amount of soil loss and is generally considered an indicator of desertification hence mapping these gully features provides essential information needed on sediment production identification of vulnerable areas for gully formation land degradation and environmental and socio economical effects this paper investigates the use of object oriented image analysis ooa to extract gully erosion features from satellite imagery using a combination of topographic spectral shape geometric and contextual information obtained from ikonos and geoeye 1 data a rule set was developed and tested for a semi arid to sub humid region in morocco the percentage of gully system area indicated negligible overestimations between the reference area and the ooa area in two sub watersheds 0 03 and 1 77 we also observed that finer gully related edges within the complex gully systems were better identified semi automatically than was possible by manual digitization suggesting higher detection accuracy ooa based gully mapping is quicker and more objective than traditional methods and is thus better suited to provide essential information for land managers to support their decision making processes and for the erosion research community

introduction to proceedings from 6th international conference on tidal sedimentology this volume of marine geology is the outgrowth of the 6th international conference on tidal sedimentology tidalites 2004 held at department of geography university of copenhagen in august 2004 this series of conferences on tidal sedimentology is organized with the purpose of bringing together sedimentologists who work with tide dominated depositional systems the conferences are planned with an interval of four years and deal with various aspects of modern and ancient tidal or tide influenced sedimentation and related physical geomorphological biological geochemical and geotechnical studies in clastic carbonate and or mixed settings the first meeting was held in utrecht the netherlands in august 1985 de boer et al 1988 the second in calgary canada in august 1989 smith et al 1991 the third in wilhelmshaven germany in august 1992 flemming and barthloma 1995 the fourth in savannah georgia usa in may 1996 alexander et al 1998 and the fifth in seoul south korea in june 2000 park and davis 2001

predicting the landslides triggered by the 2009 96e ida tropical storms in the ilopango caldera area el salvador ca optimizing mars based model building and validation strategies the main topic of this research was to evaluate the effect in the performance of stochastic landslide susceptibility models produced by differences between the triggering events of the calibration and validation datasets in the caldera ilopango area el salvador mars multivariate adaptive regression splines based susceptibility modeling was applied using a set of physical environmental predictors and two remotely recognized landslide inventories one dated at 2003 1503 landslides which was the result of a normal rainfall season and one which was produced by the combined effect of the ida hurricane and the 96e tropical depression in 2009 2237 landslides both the event inventories included shallow debris flow or slide landslides which involved the weathered mantle of the pyroclastic rocks that largely outcrop in the study area to this aim different model building and validation strategies were applied self validation forward and backward chrono validations and their performances evaluated both through cutoff dependent and independent metrics all of the tested models produced largely acceptable auc area under curve values albeit a loss in the predictive performance from self validation to chrono validation was observed besides in terms of positive negative predictions some critical differences arose using the 2009 extreme landslide inventory for calibration resulted in higher sensitivity but lower specificity conversely using the 2003 normal trigger landslide calibration inventory led to higher specificity but lower sensitivity with relevant increase in type ii errors these results suggest the need for investigating the extent of such effects taking multitrigger intensities inventories as a standard procedure for susceptibility assessment in areas where extreme events potentially occur

geological impacts on coastal wetland landscapes some general effects of sediment autocompaction in the holocene of northwest europe a simulation model is described providing general insights into autocompaction effects in stratigraphic sequences formed on coastal mudflats and marshes over uneven basements lithological units and buried landscapes are progressively displaced and distorted the synthetic sequences resembling bedding geometries described from the northwest european holocene autocompaction also promotes local deposition rates that may greatly exceed the rates at which accommodation space is created transgressive silts are associated with especially large deposition rates because of the high compressibility of underlying peats the experimental relationships between apparent rates of sea level rise and bed thickness resemble empirical trends for the holocene the latter are however reinforced by an intrinsic lithology related effect not included in the model

improving transferability strategies for debris flow susceptibility assessment application to the saponara and itala catchments messina italy abstract debris flows can be described as rapid gravity induced mass movements controlled by topography that are usually triggered as a consequence of storm rainfalls one of the problems when dealing with debris flow recognition is that the eroded surface is usually very shallow and it can be masked by vegetation or fast weathering as early as one two years after a landslide has occurred for this reason even areas that are highly susceptible to debris flow might suffer of a lack of reliable landslide inventories however these inventories are necessary for susceptibility assessment model transferability which is based on calibrating a susceptibility model in a training area in order to predict the distribution of debris flows in a target area might provide an efficient solution to dealing with this limit however when applying a transferability procedure a key point is the optimal selection of the predictors to be included for calibrating the model in the source area in this paper the issue of optimal factor selection is analysed by comparing the predictive performances obtained following three different factor selection criteria the study includes i a test of the similarity between the source and the target areas ii the calibration of the susceptibility model in the training source area using different criteria for the selection of the predictors iii the validation of the models both at the source self validation through random partition and at the target transferring through spatial partition areas the debris flow susceptibility is evaluated here using binary logistic regression through a r scripted based procedure two separate study areas were selected in the messina province southern italy in its ionian itala catchment and tyrrhenian sides saponara catchment each hit by a severe debris flow event in 2009 and 2011 respectively the investigation attested that the best fitting model in the calibration areas resulted poorly performing in predicting the landslides of the test target area at the same time the susceptibility models calibrated with an optimal set of covariates in the source area allowed us to produce a robust and accurate prediction image for the debris flows activated in the saponara catchment in 2011 exploiting only the data known after the itala 2009 event

the f utility to account for pre failure topography in data driven landslide susceptibility modelling abstract the aim of most data driven landslide susceptibility assessments is to generate a map that depicts zones that are prone to future landsliding the underlying algorithms are usually trained on the basis of a dichotomous response i e landslide presences and absences and a predictor set that includes derivatives of a digital terrain model dtm literature indicates that numerous landslide susceptibility studies are built upon topographic variables which were derived from the most recently available dtm thus the available landslide information may mostly refer to events that were triggered before the topographic data was acquired the resultant predictors are therefore likely to depict the archetypal morphometric signature of past landslides i e the post failure topography however landslide susceptible terrain which did not yet fail but may fail in the future may not exhibit such a distinct post landslide topographic footprint the delineation of landslide prone terrain may therefore require an explicit consideration of the pre landslide morphology i e pre failure topography this research aimed to explore differences among landslide susceptibility models that were based on post failure topography and their counterparts associated with an approximated pre failure topographic situation the objective was to ascertain the situations in which pre failure topography should explicitly be considered or can be ignored in this context a particular emphasis was set on elaborating the influence of spatial modelling resolution and landslide dimension the research focused on a 12 km2 test site located in the walgau region vorarlberg austria where a comprehensive shallow landslide inventory was available the methodical framework consisted of pairwise confrontations of models trained on post failure topographies with their counterparts based on approximated pre failure situations mixed effects logistic regression modelling was applied separately for five raster resolutions from 1 to 25 m and two landslide size groups smaller vs larger landslides to assess the associated effects of dtm generalization and landslide size the results were evaluated by interpreting the discriminatory power of predictors modelled associations predictor importance prediction skills and the spatial prediction pattern the findings showed that dissimilarities between post failure models and their pre failure equivalents were controlled by the selected raster resolution and the size of the underlying landslides the highest degree of mismatch was detected among models that were based on a detailed topographic representation i e high raster resolution and landslides which were associated with a larger morphometric footprint i e larger landslides however these differences were observed to diminish systematically with a decreasing raster resolution the results indicate that a consideration of pre failure topography is dispensable whenever the landslide data consists of smaller events whilst modelling is conducted at a comparatively coarse resolution in contrast landslide susceptibility modelling based on larger landslides may benefit from accounting for post failure topography even though obtained prediction skills might indicate a contrary tendency

assessment of susceptibility to earth flow landslide using logistic regression and multivariate adaptive regression splines a case of the belice river basin western sicily italy abstract in this paper terrain susceptibility to earth flow occurrence was evaluated by using geographic information systems gis and two statistical methods logistic regression lr and multivariate adaptive regression splines mars lr has been already demonstrated to provide reliable predictions of earth flow occurrence whereas mars as far as we know has never been used to generate earth flow susceptibility models the experiment was carried out in a basin of western sicily italy which extends for 51 km 2 and is severely affected by earth flows in total we mapped 1376 earth flows covering an area of 4 59 km 2 to explore the effect of pre failure topography on earth flow spatial distribution we performed a reconstruction of topography before the landslide occurrence this was achieved by preparing a digital terrain model dtm where altitude of areas hosting landslides was interpolated from the adjacent undisturbed land surface by using the algorithm topo to raster this dtm was exploited to extract 15 morphological and hydrological variables that in addition to outcropping lithology were employed as explanatory variables of earth flow spatial distribution the predictive skill of the earth flow susceptibility models and the robustness of the procedure were tested by preparing five datasets each including a different subset of landslides and stable areas the accuracy of the predictive models was evaluated by drawing receiver operating characteristic roc curves and by calculating the area under the roc curve auc the results demonstrate that the overall accuracy of lr and mars earth flow susceptibility models is from excellent to outstanding however auc values of the validation datasets attest to a higher predictive power of mars models auc between 0 881 and 0 912 with respect to lr models auc between 0 823 and 0 870 the adopted procedure proved to be resistant to overfitting and stable when changes of the learning and validation samples are performed in conclusion the highly acceptable predictive skill of the statistical models confirms the reliability of the procedure adopted to reconstruct the pre failure topographic conditions such a method solves the conceptual problem arising when post failure elevation data are the only source of topographic information available to model landslide susceptibility furthermore with respect to other solutions proposed in the past which identify as unstable the conditions of landslide surroundings our approach allows for more accurate measurement of those variables e g curvature convergence index topographic position index that depend on the relative position of a cell with respect to its nearby pixels

modelling the occurrence of gullies in rangelands of southwest spain gully erosion has been recognized as an important soil degradation process in rangelands of southwest spain in this paper a relatively new data mining technique called multivariate adaptive regression splines mars was applied to construct a model capable of predicting the location of gullies a large database was used to support the model composed of a target variable presence or absence of gullies and 36 independent variables related to topography lithology soils rainfall land use and vegetation cover the performance of the model was evaluated using the receiver operating characteristic roc curve for five external datasets the model had high predictive power with values for the area under the roc curve of the external validation datasets varying from 0 75 to 0 98 1 0 being perfect prediction the most important variables explaining the spatial distribution of gullies were lithology and soil type finally the model was compiled and implemented into a geographical information system to obtain maps of susceptible areas for gully erosion these maps show that approximately 7 of the study area presents favourable conditions for the development of gullies the results demonstrate that mars constitutes a valuable model in geomorphic research and could also be a useful tool for assessing the impacts of changing climate and land use on gully erosion copyright 2009 john wiley sons ltd

prediction of landslide susceptibility using rare events logistic regression a case study in the flemish ardennes belgium abstract in this article a statistical multivariate method i e rare events logistic regression is evaluated for the creation of a landslide susceptibility map in a 200 km2 study area of the flemish ardennes belgium the methodology is based on the hypothesis that future landslides will have the same causal factors as the landslides initiated in the past the information on the past landslides comes from a landslide inventory map obtained by detailed field surveys and by the analysis of lidar light detection and ranging derived hillshade maps information on the causal factors e g slope gradient aspect lithology and soil drainage was extracted from digital elevation models derived from lidar and from topographical lithological and soil maps in landslide affected areas however we did not use the present day hillslope gradient in order to reflect the hillslope condition prior to landsliding the pre landslide hillslope was reconstructed and its gradient was used in the analysis because of their limited spatial occurrence the landslides in the study area can be regarded as rare events rare events logistic regression differs from ordinary logistic regression because it takes into account the low proportion of 1s landslides to 0s no landslides in the study area by incorporating three correction measures the endogenous stratified sampling of the dataset the prior correction of the intercept and the correction of the probabilities to include the estimation uncertainty for the study area significant model results were obtained with pre landslide hillslope gradient and three different clayey lithologies being important predictor variables receiver operating characteristic roc curves and the kappa index were used to validate the model both show a good agreement between the observed and predicted values of the validation dataset based on a qualified judgement the created landslide susceptibility map was classified into four classes i e very high high moderate and low susceptibility if interpreted correctly this classified susceptibility map is an important tool for the delineation of zones where prevention measures are needed and human interference should be limited in order to avoid property damage due to landslides

investigation of karst hydrodynamics and organization using autocorrelations and t δc curves in karst systems rain events often result in a decrease in conductivity a tracer of dissolved phase transport and an increase in turbidity a tracer of suspended solids transport at wells and springs we investigated the response to rain events at five karst outlets three springs and two wells discharging from the cretaceous chalk aquifer of the haute normandie region france as the input signal rainfall is relatively homogeneous spatially the differences in the responses at the sites provide information on the internal organization of the karst systems and their hydrodynamic functioning we used autocorrelation functions and turbidity conductivity t c hysteresis curves to analyze the responses at short time scales autocorrelation functions allow estimation of the inertia of the conduit flow system the t c curves reflect the processes of deposition resuspension and direct transport of suspended solids within the karst network the results show that i a long memory effect for conductivity indicates storage of water in the karst network and deposition of suspended solids and the transport of the dissolved phase and suspended solids is not the same ii a short memory effect for conductivity indicates that transport of the dissolved phase and suspended solids is synchronous and direct on the basis of the results at the five sites we propose three conceptual models of hydrodynamic functioning

late cenozoic tectonics of the northwestern san bernardino mountains southern california the late cenozoic structural and stratigraphic history of the northwestern san bernardino mountains supports two distinct episodes of uplift in late miocene to earliest pliocene and quaternary time that we hypothesize are related to movements on low angle structures beneath the range in this paper we document the nature distribution and timing of late cenozoic deformation and deposition in the northwestern san bernardino mountains and we illustrate the neotectonic evolution of the area in a series of interpretive paleotectonic block diagrams in the first episode of deformation late miocene to earliest pliocene motion on the south southwest directed squaw peak thrust system disrupted drainage in pre existing miocene nonmarine basins and uplifted the western third of the present range to form the ancestral san bernardino mountains crystalline rocks of the san bernardino mountains were thrust southward across the present site of the san andreas fault between 9 5 and 4 1 ma at a time when the san gabriel fault was the active strand of the san andreas transform system we speculate that the liebre mountain crystalline block at the northern margin of the ridge basin may be the missing upper plate of the squaw peak thrust now offset along the san andreas fault the second episode of deformation began with uplift of the northern plateau of the modern san bernardino mountains on north directed range front thrusts in early pleistocene time between 2 0 and 1 5 ma synchronous uplift of the northern plateau recorded in early pleistocene fanglomerates on the northwestern margin of the range is interpreted to be the result of movement of a relatively coherent crustal block northward up a south dipping detachment ramp beneath the central range in middle pleistocene time activity on the northern range front began to wane and the locus of uplift shifted to a narrow zone of arching and northward tilting adjacent to the san andreas fault which subsequently migrated rapidly northwestward along the san andreas fault from the western san bernardino mountains into the northeastern san gabriel mountains we attribute this pattern of deformation to the passage of a bulge or strike slip ramp attached to the southwest side of the san andreas fault at depth

estimating the quality of landslide susceptibility models we present a landslide susceptibility model for the collazzone area central italy and we propose a framework for evaluating the model reliability and prediction skill the landslide susceptibility model was obtained through discriminant analysis of 46 thematic environmental variables and using the presence of shallow landslides obtained from a multi temporal inventory map as the dependent variable for statistical analysis by comparing the number of correctly and incorrectly classified mapping units it is established that the model classifies 77 0 of 894 mapping units correctly model fitting performance is investigated by comparing the proportion of the study area in each probability class with the corresponding proportion of landslide area we then prepare an ensemble of 350 landslide susceptibility models using the same landslide and thematic information but different numbers of mapping units this ensemble is exploited to investigate the model reliability including the role of the thematic variables used to construct the model and the model sensitivity to changes in the input data by studying the variation of the model s susceptibility estimate the error associated with the susceptibility assessment for each mapping unit is determined this result is shown on a map that complements the landslide susceptibility map prediction skill of the susceptibility model is then estimated by comparing the forecast with two recent event inventory maps the susceptibility model is found capable of predicting the newly triggered landslides a general framework for testing a susceptibility model is proposed including a scheme for ranking the quality of the susceptibility assessment

exploiting maximum entropy method and aster data for assessing debris flow and debris slide susceptibility for the giampilieri catchment north eastern sicily italy this study aims at evaluating the performance of the maximum entropy method in assessing landslide susceptibility exploiting topographic and multispectral remote sensing predictors we selected the catchment of the giampilieri stream which is located in the north eastern sector of sicily southern italy as test site on 1 october 2009 a storm rainfall triggered in this area hundreds of debris flow avalanche phenomena causing extensive economical damage and loss of life within this area a presence only based statistical method was applied to obtain susceptibility models capable of distinguishing future activation sites of debris flow and debris slide which where the main source of failure mechanisms for flow or avalanche type propagation the set of predictors used in this experiment comprised primary and secondary topographic attributes derived by processing a high resolution digital elevation model corine land cover data and a set of vegetation and mineral indices obtained by processing multispectral aster images all the selected data sources are dated before the disaster a spatially random partition technique was adopted for validation generating 50 replicates for each of the two considered movement typologies in order to assess accuracy precision and reliability of the models the debris slide and debris flow susceptibility models produced high performances with the first type being the best fit the evaluation of the probability estimates around the mean value for each mapped pixel shows an inverted relation with the most robust models corresponding to the debris flows with respect to the role of each predictor within the modelling phase debris flows appeared to be primarily controlled by topographic attributes whilst the debris slides were better explained by remotely sensed derived indices particularly by the occurrence of previous wildfires across the slope the overall excellent performances of the two models suggest promising perspectives for the application of presence only methods and remote sensing derived predictors copyright 2016 john wiley sons ltd

exploring the effect of absence selection on landslide susceptibility models a case study in sicily italy abstract a statistical approach was employed to model the spatial distribution of rainfall triggered landslides in two areas in sicily italy that occurred during the winter of 2004 2005 the investigated areas are located within the belice river basin and extend for 38 5 and 10 3 km 2 respectively a landslide inventory was established for both areas using two google earth images taken on october 25th 2004 and on march 18th 2005 to map slope failures activated or reactivated during this interval geographic information systems gis were used to prepare 5 m grids of the dependent variables absence presence of landslide and independent variables lithology and 13 dem derivatives multivariate adaptive regression splines mars were applied to model landslide susceptibility whereas receiver operating characteristic roc curves and the area under the roc curve auc were used to evaluate model performance to evaluate the robustness of the whole procedure we prepared 10 different samples of positive landslide presence and negative landslide absence cases for each area absences were selected through two different methods i extraction from randomly distributed circles with a diameter corresponding to the mean width of the landslide source areas and ii selection as randomly distributed individual grid cells a comparison was also made between the predictive performances of models including and not including the lithology parameter the models trained and tested on the same area demonstrated excellent to outstanding fit auc 0 8 on the other hand predictive skill decreases when measured outside the calibration area although most of the landslides occur where susceptibility is high and the overall model performance is acceptable auc 0 7 the results also showed that the accuracy of the landslide susceptibility models is higher when lithology is included in the statistical analysis models whose absences were selected using random circles showed a significantly better performance when learning and validation samples were extracted from the same area whereas conversely no significant difference was observed when testing the models outside the training area

reliability of lunar orbital periods extracted from ancient cyclic tidal rhythmites abstract ancient tidal periods extracted from the geologic record are useful to constrain and calibrate theoretical models of the evolution of the earth moon system analysis of rocks that contain such tidal periodicities termed cyclic rhythmites have tended to concentrate on long series and have focused on the more obvious periods for example neap spring periods have been the most widely discussed such information can be reliably extracted from bedform thickness series measured within laterally accreted tidal bundles and vertically accreted tidal laminae other lunar orbital data is also encoded in cyclic rhythmites however this additional information has been much less extensively applied to earth moon models herein short segments of well formed cyclic rhythmites are examined to determine how reliably the various tidal periods can be extracted via harmonic analysis rhythmite series analyzed here exhibit well formed neap spring tidal periods and also exhibit a prominent fortnightly inequality or a variation in the height of successive spring tides this inequality is related to the elliptical nature of the lunar orbit anomalistic month and it is demonstrated that this period can also be reliably extracted from cyclic rhythmites tropical periods which reflect the changing lunar declination that occurs during a tropical month have also been reported from cyclic rhythmites unlike synodic and anomalistic periods the apparent tropical periods extracted from some cyclic rhythmites do not always accurately correspond to the expected values in only a few cases can this period be reliably extracted from short segments of cyclic tidal rhythmite data this period is commonly only poorly encoded in rhythmites because 1 it tends to be masked by higher amplitude synodic periods and 2 it is not well expressed within predominantly semidiurnal tidal systems samples selected from the proterozoic and phanerozoic tend to be more common during specific intervals of geologic time these intervals were characterized by glacio eustatic flux and in some cases by unique continental configurations understanding these basic controls on rhythmite occurrences should aid in the discovery of additional examples

spatial statistical modeling of shallow landslides validating predictions for different landslide inventories and rainfall events abstract statistical models that exploit the correlation between landslide occurrence and geomorphic properties are often used to map the spatial occurrence of shallow landslides triggered by heavy rainfalls in many landslide susceptibility studies the true predictive power of the statistical model remains unknown because the predictions are not validated with independent data from other events or areas this study validates statistical susceptibility predictions with independent test data the spatial incidence of landslides triggered by an extreme rainfall in a study area was modeled by logistic regression the fitted model was then used to generate susceptibility maps for another three study areas for which event based landslide inventories were also available all the study areas lie in the northern foothills of the swiss alps the landslides had been triggered by heavy rainfall either in 2002 or 2005 the validation was designed such that the first validation study area shared the geomorphology and the second the triggering rainfall event with the calibration study area for the third validation study area both geomorphology and rainfall were different all explanatory variables were extracted for the logistic regression analysis from high resolution digital elevation and surface models 2 5 m grid the model fitted to the calibration data comprised four explanatory variables i slope angle effect of gravitational driving forces ii vegetation type grassland and forest root reinforcement iii planform curvature convergent water flow paths and iv contributing area potential supply of water the area under the receiver operating characteristic roc curve auc was used to quantify the predictive performance of the logistic regression model the auc values were computed for the susceptibility maps of the three validation study areas validation auc the fitted susceptibility map of the calibration study area apparent auc 0 80 and another susceptibility map obtained for the calibration study area by 20 fold cross validation cross validation auc 0 74 the auc values of the first and second validation study areas 0 72 and 0 69 respectively and the cross validation auc matched fairly well and all auc values were distinctly smaller than the apparent auc based on the apparent auc one would have clearly overrated the predictive performance for the first two validation areas rather surprisingly the auc value of the third validation study area 0 82 was larger than the apparent auc a large part of the third validation study area consists of gentle slopes and the regression model correctly predicted that no landslides occur in the flat parts this increased the predictive performance of the model considerably the predicted susceptibility maps were further validated by summing the predicted susceptibilities for the entire validation areas and by comparing the sums with the observed number of landslides the sums exceeded the observed counts for all the validation areas hence the logistic regression model generally over estimated the risk of landslide occurrence obviously a predictive model that is based on static geomorphic properties alone cannot take a full account of the complex and time dependent processes in the subsurface however such a model is still capable of distinguishing zones highly or less prone to shallow landslides

holocene evolution of the coast of holland abstract the holocene evolution of the coast of holland was controlled by the complex interaction of such diverse parameters as wave and tidal climate the rate of sea level rise and the morphology of the pre transgressional surface the latter in combination with the rate of sea level rise mainly determines the location of sediments sources and sinks while the hydrodynamic parameters mainly determine the rate and direction of sediment transport in the early holocene the low sea level in the shallow southern north sea strongly affected wave climate and tidal regime however the barrier and back barrier sedimentary record since 5000 14c yrs b p gives us no reason to assume major changes in these parameters since then so we conclude that breaks in barrier development are due to variations in rate of sea level rise inl combination with the morphology of the pre transgressional surface the transformation from an open tide dominated to a closed wave dominated coast which occurred in the subboreal period and the concomitant change in barrier movement from transgressive to regressive around 5000 yrs b p are the main events in the development of the coast of holland up to the middle ages the morphology of the pre transgressional surface gives a shoreline in the late atlantic which consists of two protruding headlands separated by a large tidal basin the southern headland is the alluvial plain of the rhine and the meuse the northern headland constitutes the moraines of the texel high the tidal basin in between is connected to the north sea by a large number of inlets the rate of sea level rise at that time 1 m century outran the supply of sediment to the tidal basin after 6000 yrs b p the rate of sea level rise decreased gradually whereas the rate of sediment supply remained constant this led to a gradual decrease in the tidal prisms of the inlets as the tidal basin was filled in with sediment shortly before 5000 yrs b p the first channels silted up and closed the last tidal channel disappeared around 3300 yrs b p leaving two inlets along the coast which were both connected to the river rhine the closure of the first inlets occurred at the same time as the barrier began prograding because 1 the rate of sea level rise diminished considerably 2 not all the sand supplied by longshore and cross shore transport disappeared into the tidal basin but instead could be used for barrier progradation and 3 ebb tidal deltas of the closed inlets provided major sand sources the prograding barrier sequence enclosed between the two headlands roughly forms a closed system using the relationships between tidal prism cross sectional area of inlets and volume of the ebb tidal delta and the results of modelling of longshore transport along the subboreal coast under present day wave conditions a simple sand budget for the coast of holland is given which shows that a large part of the sand now stored in the barrier sequence was obtained by cross shore transport from the north sea

microgranulometric approach to a chalk karst western paris basin france abstract by definition karst is the result of dissolution and if the rock is not completely soluble residues will remain acquired particles these insoluble residues provide a history of karstic activity and can be found in the outflows after a possible storage period in the endokarst a direct connection even if temporary between the endokarst and the surface is reflected by the contribution of particles which are referred to as inherited we have studied the chalk karsts of haut normandie by comparing microgranulometric spectra of suspended matter sm in subterranean waters and in solutions of the main surface formations clay with flints complex cfc and loess and the chalk dissolution products of all local stratigraphic levels based on these microgranulometric spectra we propose a conceptual model for processes occurring in chalk karsts and a classification scheme for karstified systems according to how such systems deal with particles in a closed karst the suspended matter tends to come from the chalk itself while in the case of an open karst the majority of suspended particles comes from surface formations this notion of openness differs from the currently used categorization into allogenic and autogenic systems which depends upon an impermeable cover concentrating the infiltration

quantitative analysis of land surface topography land surface topography significantly affects the processes of runoff and erosion a system which determines slope aspect and curvature in both the down slope and across slope directions is developed for an altitude matrix also the upslope drainage area and maximum drainage distance are determined for every point within the altitude matrix a fortran 66 program performs the analysis

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