remote sensing estimates of glacier mass balances in the himachal pradesh western himalaya india abstract although they correspond to an important fraction of the total area of mountain glaciers 33 000 km2 out of 546 000 km2 himalayan glaciers and their mass balance are poorly sampled for example between 1977 and 1999 the average area surveyed each year on the field was 6 8 km2 only no direct mass balance measurement is available after 1999 to contribute to fill this gap we use remote sensing data to monitor glacier elevation changes and mass balances in the spiti lahaul region 32 2 n 77 6 e himachal pradesh western himalaya india our measurements are obtained by comparing a 2004 digital elevation model dem to the 2000 srtm shuttle radar topographic mission topography the 2004 dem is derived from two spot5 satellite optical images without any ground control points this is achieved thanks to the good on board geolocation of spot5 scenes and using srtm elevations as a reference on the ice free zones before comparison on glaciers the two dems are analyzed on the stable areas surrounding the glaciers where no elevation change is expected two different biases are detected a long wavelength bias affects the spot5 dem and is correlated to an anomaly in the roll of the spot5 satellite a bias is also observed as a function of altitude and is attributed to the srtm dataset both biases are modeled and removed to permit unbiased comparison of the two dem on the 915 km2 ice covered area digitized from an aster image on most glaciers a clear thinning is measured at low elevations even on debris covered tongues between 1999 and 2004 we obtain an overall specific mass balance of 0 7 to 0 85 m a water equivalent depending on the density we use for the lost or gained material in the accumulation zone this rate of ice loss is twice higher than the long term 1977 to 1999 mass balance record for himalaya indicating an increase in the pace of glacier wastage to assess whether these ice losses are size dependant all glaciers were classified into three samples according to their areal extent all three samples show ice loss the loss being higher for glaciers larger than 30 km2 in the case of the benchmark chhota shigri glacier a good agreement is found between our satellite observations and the mass balances measured on the field during hydrological years 2002 2003 and 2003 2004 future studies using a similar methodology could determine whether similar ice losses have occurred in other parts of the himalaya and may allow evaluation of the contribution of this mountain range to ongoing sea level rise

an integrated lightweight ice penetrating radar system we describe a portable low frequency impulse radar system intended for ground based surveys that employs off the shelf hardware integrated with custom designed software the hardware comprises a 1 200 mhz transmitter digitizer computer and gps receiver which together weigh 1 5 kg the entire system including waterproof enclosures and batteries suited for 8 hours of continuous operation weighs 10 kg plus the weight of the antenna housing the system design is flexible permitting hardware components such as the digitizer or navigation device to be exchanged the software includes acquisition parameter control real time visual ice depth rendering and data management capabilities using a hierarchical data format the system described here has been successfully used to sound polythermal ice up to 220 m thick in ski based surveys in the yukon canada and temperate ice up to 550 m thick in machine based surveys in iceland

gis based landslide susceptibility mapping using bivariate statistical analysis in devrek zonguldak turkey devrek town with increasing population is located in a hillslope area where some landslides exist therefore landslide susceptibility map of the area is required the purpose of this study was to generate a landslide susceptibility map using a bivariate statistical index and evaluate and compare the results of the statistical analysis conducted with three different approaches in seed cell concept resulting in different data sets in geographical information systems gis based landslide susceptibility mapping applied to the devrek region the data sets are created from the seed cells of a crowns and flanks b only crowns and c only flanks of the landslides by using ten different causative parameters of the study area to increase the data dependency of the analysis all parameter maps are classified into equal frequency classes based directly on the percentile divisions of each corresponding seed cell data set the resultant maps of the landslide susceptibility analysis indicate that all data sets produce fairly acceptable results in each data set analysis elevation lithology slope aspect and drainage density parameters are found to be the most contributing factors in landslide occurrences the results of the three data sets are compared using seed cell area indexes scai this comparison shows that the crown data set produces the most accurate and successful landslide susceptibility map of the study area

landslide characteristics and slope instability modeling using gis lantau island hong kong steep terrain and high a frequency of tropical rainstorms make landslide occurrence on natural terrain a common phenomenon in hong kong this paper reports on the use of a geographical information systems gis database compiled primarily from existing digital maps and aerial photographs to describe the physical characteristics of landslides and the statistical relations of landslide frequency with the physical parameters contributing to the initiation of landslides on lantau island in hong kong the horizontal travel length and the angle of reach defined as the angle of the line connecting the head of the landslide source to the distal margin of the displaced mass are used to describe runout behavior of landslide mass for all landslides studied the horizontal travel length of landslide mass ranges from 5 to 785 m with a mean value of 43 m and the average angle of reach is 27 7 this gis database is then used to obtain a logistic multiple regression model for predicting slope instability it is indicated that slope gradient lithology elevation slope aspect and land use are statistically significant in predicting slope instability while slope morphology and proximity to drainage lines are not important and thus excluded from the model this model is then imported back into the gis to produce a map of predicted slope instability the results of this study demonstrate that slope instability can be effectively modeled by using gis technology and logistic multiple regression analysis

medium scale earthflow susceptibility modelling by remote sensing and geographical information systems based multivariate statistics approach an example from northeastern turkey the aim of the present study was to produce an earthflow susceptibility map for the city center and environs of the province of rize located at the northeastern part of turkey the study area is the rainiest region of turkey and due to the triggering effect of precipitation earthflows are frequently observed in and around the study area besides this point weathered rock units and steep topography accompany with precipitation for the occurrence of earthflow cases considering this point an earthflow susceptibility mapping was inferred to be a necessity for the area parameters such as lithology slope gradient slope aspect topographical wetness index twi stream power index spi slope curvature and sediment capacity index ls were considered to be earthflow conditioning parameters a multi temporal earthflow inventory map for a period of 4 years 2011 2015 was initially generated by way of remote sensing approach and field surveys earthflow susceptibility map was produced using the logistic regression method after which the produced susceptibility map was validated the mapped earthflows were separated into two groups prior to modelling and validation the first group was for training and the second group was for validation steps the accuracy of the model was measured by fitting them to a validation set of mapped earthflows area under curvature auc approach was applied for validation purposes the prediction capability of the earthflow susceptibility map produced can be regarded as acceptable in accordance with the auc values of 0 62 for the logistic regression model based on these results the obtained earthflow susceptibility map can be used to mitigate hazards related to landslides and to aid in land use planning for the rize city center

assessing landslide potential using gis soil wetness modeling and topographic attributes payette river idaho this study utilizes gis modeling to determine if the location of 559 landslides in the 875 km2 catchment of the middle fork of the payette river idaho can be predicted based on topographic attributes and a wetness index generated by the dynwet model slope and elevation were significantly related to landslide occurrence at this landscape scale aspect was also retained as a variable for further analysis because despite a non significant chi square relation to landslide occurrence graphical analysis suggested a relation between aspect and mass wasting chi square analysis indicated that plan and profile curvature flow path length upslope contributing area and the dynwet based moisture index were not significantly related to landsliding a bayesian probability model based on combinations of elevation slope aspect and wetness indicates that elevation exhibits the closest relation to landsliding followed by slope but that neither aspect nor wetness index values help in prediction the bayesian probability model using elevation and slope generates a map of relative landslide risk that can be used to direct activities away from mass wasting prone areas the association between elevation and landslides is perplexing but is perhaps due to the location of logging road at specific elevations roads could not be included in the input data for analysis because they have not been adequately mapped the lack of explanation provided by the dynwet wetness index was also surprising and may be due to the 30 m digital elevation model dem and the soils data having resolutions too coarse to adequately portray local variations key to mass wasting we believe the inadequacy of data to drive the models is typical of the majority of catchment scale setting for now the ability of researchers to effectively model landscape scale landsliding is more limited by the type resolution and quality of available data than by the quality of the landslide models

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

interactive statistical analysis of predisposing factors for earthquake triggered landslides a case study of the 2013 lushan china ms7 0 earthquake remote sensing data and field investigations indicate that at least 3 878 landslides were induced by the 2013 lushan china ms7 0 earthquake this study selects a square area of 100 km 100 km around the epicenter to make an interactive statistical analysis to these landslides percentages of landslide number and landslide concentration are calculated based on a gis platform so as to find out the relationship between the distribution of landslides and six predisposing factors including elevation slope angle slope aspect slope curvature geologic ages of underlying bedrocks and peak ground acceleration pga in general the correlations from interactive statistical analysis show a good consistency with the results from the bivariate statistics however several abnormal values are observed for example the relationship between slope aspect and co seismic landslides is more easily influenced in the areas of slope angles larger than 40o or with the pga value range of 0 36 0 44 g the correlation between slope angle and co seismic landslides is stronger in areas with underlying bedrocks of the triassic age interactive statistical analysis of co seismic landslides controlled by the factors in this study can effectively compensate the results from bivariate statistical analysis which allows us to better understand spatial distribution patterns of earthquake triggered landslides

a distributed temperature index ice and snowmelt model including potential direct solar radiation hourly melt and discharge of storglaciaren a small glacier in sweden were computed for two melt seasons applying temperature index methods to a 30 m resolution grid for the melt component the classical degree day method yielded a good simulation of the seasonal patient of discharge but the pronounced melt induced daily discharge cycles were not captured modelled degree day factors calculated for every hour and each gridcell from melt obtained from a distributed energy balance model varied substantially both diurnally and spatially a new distributed temperature index model is suggested attempting to capture both the pronounced diurnal melt cycles and the spatial variations in melt due to the effects of surrounding topography this is accomplished by including a radiation index in terms of potential clear sky direct solar radiation and thus without the need for other data besides air temperature this approach improved considerably the simulation of diurnal discharge fluctuations and yielded a more realistic spatial distribution of melt rates the incorporation of measured global radiation to account for the reduction in direct solar radiation due to cloudiness did not lead to additional improvement in model performance

recent volume and area changes of kaskawulsh glacier yukon canada recent surface elevation changes of kaskawulsh glacier yukon canada are quantified by comparing an air photo derived dem from 1977 and airborne lidar measurements from 1995 2000 and 2007 surface area changes are assessed using historical aerial photography from 1956 and satellite imagery from 1977 to 2007 combined these measurements provide some of the first detailed records of volume change of a large yukon glacier between 1977 and 2007 kaskawulsh glacier underwent a decrease in area of 1 53 and a decrease in volume of 3 27 5 94 km 3 w e the terminus also retreated by 655 m over the period 1956 2007 there was relatively minor volume change over the period 1977 95 0 01 km 3 w e a 1 while over the periods 1995 2000 and 2000 07 volume losses occurred at a relatively constant rate of 0 51 and 0 50 km 3 a 1 w e respectively since 1995 thinning has been prominent throughout the ablation zone while relative stability and even slight thickening has occurred in the accumulation zone these findings are similar to those recently observed at other nearby alaskan glaciers

sediment transport mechanisms on soil mantled hillslopes landscape evolution is modeled widely using a simple creep law for complex processes of sediment transport here field data show how a new transport model combined with an exponential soil production law better captures spatial variations of soil thick ness on hillslopes we combine parameterizations of simple and depth dependent creep with overland flow to predict soil thickness and suggest how soil distribution evolves in response to climatic and tectonic forcing we present an empirical expression for the response time of the system to external forcing that shows strong dependence on relief and is independent of soil production rate we suggest that this parameterization may be used to quantify upland carbon storage and removal and predict impacts of defor estation or rapid climatic changes

the 17 march 2005 kuzulu landslide sivas turkey and landslide susceptibility map of its near vicinity landslides are common natural hazards in the seismically active north anatolian fault zone of turkey although seismic activity heavy rainfall channel incisions and anthropogenic effects are commonly the main triggers of landslides on march 17 2005 a catastrophic large landslide in sivas northeastern of turkey the kuzulu landslide was triggered by snowmelt without any other precursor the initial failure of the kuzulu landslide was rotational following the rotational failure the earth material in the zone of accumulation exhibited an extremely rapid flow caused by steep gradient and high water content the agnus creek valley where kuzulu village is located was filled by the earth flow material and a landslide dam was formed on the upper part of agnus creek the distance from the toe of the rotational failure down to the toe of the earth flow measured more than 1800 m with about 12 5 million m3 of displaced earth material the velocity of the kuzulu landslide was extremely fast approximately 6 m s the main purposes of this study are to describe the mechanism and the factors conditioning the kuzulu landslide to present its environmental impacts and to produce landslide susceptibility maps of the kuzulu landslide area and its near vicinity for this purpose a detailed landslide inventory map was prepared and geology slope aspect elevation topographic wetness index and stream power index were considered as conditioning factors during the susceptibility analyses the conditional probability approach was used and a landslide susceptibility map was produced the landslide susceptibility map will help decision makers in site selection and the site planning process the map may also be accepted as a basis for landslide risk management studies to be applied in the study area

assessing susceptibility to landslides using models to understand observed changes in slopes abstract a map of landslide susceptibility is a necessary tool for proper planning and selection of sites for agriculture infrastructure and other human developments the paonia mcclure pass area of colorado usa is well known for active mass movements large losses of property and risks to people highlight the need to accurately map susceptibility to shallow landslides and to identify safe locations for infrastructure and residential development we mapped 735 active mass movements and 17 factors about each one the weights of evidence frequency ratio of landslides and fuzzy logic method were used to create an optimum map of landslide susceptibility weights of the evidence were used to categorize continuous factor data frequency ratios of shallow landslides were used to assign the membership values for the categories of the factors and the fuzzy logic method was used to integrate the membership values four models from the fuzzy inference network of mapping susceptibility to shallow landslides were developed based on the combination of factors using five types of fuzzy operators the first inference network model was comprised of the combination of factors which are independent of each other the second third and the fourth inference network models were developed such that factors are not necessarily independent of each other these models combine all dependent and independent factors based on the expert s knowledge intermediate steps in the second third and fourth models were developed by combining the fuzzy factors in the first step by fuzzy or fuzzy and and fuzzy or plus fuzzy and operations respectively all models predicted similar percentages of observed shallow landslides with the fuzzy gamma operation although the prediction capabilities of all the models are not significantly different the fourth model is the best because it is the only model that accommodates the under sampled and missed landslide data and the effect of increasing and decreasing gamma values the first and third models create a problem if a category of a factor has a 0 membership value because of the absence or under sampling of shallow landslides the second model incurs the highest increasing effect of gamma values and the third model incurs the highest decreasing effect of gamma values the approaches described in this paper reduce the uncertainties associated with the categorization of continuous data determination of fuzzy membership values and the combination of factors that causes shallow landslides

integrating multidisciplinary science modelling and impact data into evolving syn event volcanic hazard mapping and communication a case study from the 2012 tongariro eruption crisis new zealand abstract new zealand s tongariro national park volcanoes produce hazardous eruptions every few years to decades on 6 august 2012 the te maari vent of tongariro volcano erupted producing a series of explosions and a fine ash of minor volume which was dispersed rapidly to the east this manuscript presents a summary of the eruption impacts and the way these supported science communication during the crisis particularly in terms of hazard map development the most significant proximal impact was damage from pyroclastic surges and ballistics to the popular and economically important tongariro alpine crossing track the only hazard to affect the medial impact zone was a few mms of ashfall with minor impacts field testing indicated that the te maari ash had extremely low resistivity when wetted implying a very high potential to cause disruption to nationally important power transmission networks via the mechanism of insulator flashover this was not observed presumably due to insufficient ash accumulation on insulators virtually no impacts from distal ashfall were reported post event analysis of pm10 data demonstrates the additional value of regional air quality monitoring networks in quantifying population exposure to airborne respirable ash while the eruption was minor it generated a high level of public interest and a demand for information on volcanic hazards and impacts from emergency managers the public critical infrastructure managers health officials and the agriculture sector meeting this demand fully taxed available resources we present here aspects of the new zealand experience which may have wider applicability in moving towards improved integration of hazard impact information mapping and communication these include wide use of a wiki technical clearinghouse and email listservs a focus on multi agency consistent messages and a recently developed environment of collaboration and alignment of both research funding and technical science advice hazard maps were integral to science communication during the crisis but there is limited international best practice information available on hazard maps as communication devices as most volcanic hazard mapping literature is concerned with defining hazard zones we propose that hazard maps are only as good as the communications framework and inter agency relationships in which they are embedded and we document in detail the crisis hazard map development process we distinguish crisis hazard maps from background hazard maps and ashfall prediction maps illustrating the complementary nature of these three distinct communication mechanisms we highlight issues that arose and implications for the development of future maps

response of debris covered glaciers in the mount everest region to recent warming and implications for outburst flood hazards abstract in areas of high relief many glaciers have extensive covers of supraglacial debris in their ablation zones which alters both rates and spatial patterns of melting with important consequences for glacier response to climate change wastage of debris covered glaciers can be associated with the formation of large moraine dammed lakes posing risk of glacier lake outburst floods glofs in this paper we use observations of glaciers in the mount everest region to present an integrated view of debris covered glacier response to climate change which helps provide a long term perspective on evolving glof risks in recent decades debris covered glaciers in the everest region have been losing mass at a mean rate of 0 32 m yr 1 although in most cases there has been little or no change in terminus position mass loss occurs by 4 main processes 1 melting of clean ice close to glacier elas 2 melting beneath surface debris 3 melting of ice cliffs and calving around the margins of supraglacial ponds and 4 calving into deep proglacial lakes modelling of processes 1 and 2 shows that everest region glaciers typically have an inverted ablation gradient in their lower reaches due to the effects of a down glacier increase in debris thickness mass loss is therefore focused in the mid parts of glacier ablation zones causing localised surface lowering and a reduction in downglacier surface gradient which in turn reduce driving stress and glacier velocity so the lower ablation zones of many glaciers are now stagnant model results also indicate that increased summer temperatures have raised the altitude of the rain snow transition during the summer monsoon period reducing snow accumulation and ice flux to lower elevations as downwasting proceeds formerly efficient supraglacial and englacial drainage networks are broken up and supraglacial lakes form in hollows on the glacier surface ablation rates around supraglacial lakes are typically one or two orders of magnitude greater than sub debris melt rates so extensive lake formation accelerates overall rates of ice loss most supraglacial lakes are perched above hydrological base level and are susceptible to drainage if they become connected to the englacial drainage system speleological surveys of conduits show that large englacial voids can be created by drainage of warm lake waters along pre existing weaknesses in the ice roof collapses can open these voids up to the surface and commonly provide the nuclei of new lakes thus by influencing both lake drainage and formation englacial conduits exert a strong control on surface ablation rates an important threshold is crossed when downwasting glacier surfaces intersect the hydrological base level of the glacier base level lakes formed behind intact moraine dams can grow monotonically and in some cases can pose serious glof hazards glacier termini can evolve in different ways in response to the same climatic forcing so that potentially hazardous lakes will form in some situations but not others additionally the probability of a flood is not simply a function of lake volume but depends on the geometry and structure of the dam and possible trigger mechanisms such as ice or rockfalls into the lake satellite based measurements of glacier surface gradient and ice velocities allow probable future locations of base level lakes to be identified a base level lake has begun to grow rapidly on ngozumpa glacier west of mount everest and could attain a volume of 10 8 m 3 within the next 2 or 3 decades unless mitigation efforts are undertaken this lake could pose considerable glof hazard potential

presenting regional shallow landslide movement on three dimensional digital terrain abstract a storm can trigger numerous shallow landslides on hilly terrains this paper presents a distributed cell model for presenting regional shallow landslide movement on a three dimensional digital terrain the model consists of five components namely a digital terrain module a spatial rainfall distribution module an infiltration analysis module a slope stability evaluation module and a movement prediction module the locations and volumes of landslides are analyzed first through rainfall infiltration and slope stability analyses the detached material is assumed to move along the steepest path from one cell to a lower cell empirical equations that are developed based on local landslide inventories are adopted as a landslide movement cessation criterion the effect of landslide size on travel distance is considered by grouping unstable cells that are bounded at least at one side or corner the uncertainties in soil shear strength parameters and the landslide movement process are considered in determining the possible bounds of travel distance the movement analysis method is applied to a 164 5 km 2 hilly terrain in the wenchuan earthquake zone to test its performance in presenting regional shallow landslide movement the method predicts the volume of landslides reasonably well the observed and computed movement traces and deposition locations of the detached material also agree reasonably well the volume of individual landslide and travel distance may be substantially underestimated if the size effect is not considered

gis based landslide susceptibility mapping using analytical hierarchy process and bivariate statistics in ardesen turkey comparisons of results and confirmations abstract the ardesen area is prone to landslides because of the climate conditions geologic and geomorphologic characteristics of the region as in previous years in 2001 due to heavy rainfall there were many landslides resulting in damage and human casualties there is still a great danger of further landslides in the region therefore it is vitally important to prepare a landslide susceptibility map of the region in this study the analytical hierarchy process ahp the statistical index wi and weighting factor wf methods were used to produce and later compare three susceptibility maps for this purpose thematic layers including landslide inventory lithology weathering slope aspect land cover distance to stream drainage density and distance to road were used in this study area 98 of landslides occurred in highly or completely weathered units lithology weathering land cover and slope data layers were found to be important factors in the study area to confirm the practicality of the three susceptibility maps were compared with a landslide activity map containing 16 active landslide zones the outcome was that the active landslide zones do not completely fit into the high and very high susceptibility classes but 81 3 of these landslide zones fall into the high and very high susceptibility zones of the ahp method while this is 62 5 in the case of wi method and 68 8 with the wf method in spite of the results obtained in this study the development of a susceptibility map is usually determined by the needs and available resources the results showed that the ahp method gave a more realistic picture of the actual distribution of landslide susceptibility than the wi and wf methods

regional scale landslide activity and landslide susceptibility zonation in the nepal himalaya landslide susceptibility zonation mapping is a fundamental procedure for geo disaster management in tropical and sub tropical regions recently various landslide susceptibility zonation models have been introduced in nepal with diverse approaches of assessment however validation is still a problem additionally the role of various predisposing causative parameters for landslide activity is still not well understood in the nepal himalaya to address these issues of susceptibility zonation and landslide activity about 4 000 km2 area of central nepal was selected for regional scale assessment of landslide activity and susceptibility zonation mapping in total 655 new landslides and 9 229 old landslides were identified with the study area with the help of satellite images aerial photographs field data and available reports the old landslide inventory was blind landslide database and could not explain the particular rainfall event responsible for the particular landslide but considering size of the landslide blind landslide inventory was reclassified into two databases short duration high intensity rainfall induced landslide inventory and long duration low intensity rainfall induced landslide inventory these landslide inventory maps were considered as proxy maps of multiple rainfall event based landslide inventories similarly all 9 884 landslides were considered for the activity assessment of predisposing causative parameters for the nepal himalaya slope slope aspect geology and road construction activity anthropogenic cause were identified as most affective predisposing causative parameters for landslide activity for susceptibility zonation multivariate approach was considered and two proxy rainfall event based landslide databases were used for the logistic regression modelling while a relatively recent landslide database was used in validation two event based susceptibility zonation maps were merged and rectified to prepare the final susceptibility zonation map and its prediction rate was found to be more than 82 from this work it is concluded that rectification of susceptibility zonation map is very appropriate and reliable the results of this research contribute to a significant improvement in landslide inventory preparation procedure susceptibility zonation mapping approaches as well as role of various predisposing causative parameters for the landslide activity

major natural hazards in a tropical volcanic island a review for mayotte island comoros archipelago indian ocean abstract mayotte is a french overseas territory of the comoros archipelago since the 1980 mayotte has developed quickly its population has multiplied by four in less than 30 years infrastructure expanded rapidly in lowlands and slums developed in steep areas through deforestation or close to riverbeds this development urgently required steps to ensure the safety of urban areas from 2002 to 2006 a major programme of natural hazards evaluation and zonation was conducted by the french geological survey in the 17 districts of mayotte the programme resulted in the publication of the first single hazard zonation maps for mayotte at 1 25 000 scale in rural areas and at 1 10 000 scale in urban areas hazard maps regarding landslides and rock falls stream floods seismic lithological and topographical amplification potential liquefaction potential and cyclonic marine submersion were produced for mayors and land planners these atlases also included prevention guidelines to minimize risks associated with land use or urbanization within hazard prone areas this article presents the main achievements of the programme whose main problems were the absence of archives of previous studies and the original volcanic geology of the island of mayotte the atlases highlight areas with numerous landslides zones susceptible to flash floods sectors likely to be submerged by storm surges and areas subject to seismic site effects due to thick volcanic weathered formations this programme emphasizes the fundamental role in such tropical volcanic islands of a good knowledge of the weathered formations for the assessment of most natural hazards this initial hazard mapping represented the first step to achieve specific regulatory risk prevention plans for an efficient land use risk mitigation and reduction policy in mayotte

artificial neural network ensembles applied to the mapping of landslide susceptibility abstract this study proposes a comprehensive methodology to the application of an artificial neural network ensemble anne for the mapping of landslide susceptibility the identification of susceptible areas was performed on the basis of landslide inventory databases and seven parameters from three classes geomorphological elevation aspect slope topographic moisture index profile curvature geological lithology and environmental land use studies are presented for two major cities in brazil porto alegre and rio de janeiro as the main result we show that the susceptibility maps generated by the anne feature higher accuracy than those published by official organs such as the brazilian geological survey and geotechnical institute foundation geo rio this indicates that the proposed methodology can be an effective tool to assist the development of reliable landslide susceptibility maps in an efficient and agile manner

a comparison of the gis based landslide susceptibility assessment methods multivariate versus bivariate the purpose of this study is to evaluate and to compare the results of multivariate logical regression and bivariate landslide susceptibility methods in geographical information system gis based landslide susceptibility assessment procedures in order to achieve this goal the asarsuyu catchment in nw turkey was selected as a test zone because of its well known landslide occurrences interfering with the e 5 highway mountain pass

landslide hazard mapping using an expert system and a gis this paper presents a rule based expert system used to create landslide warning and alert maps using as input change of landuse data from earth observation as well as geological rainfall and earthquake data stored in a geographic information system the difference with other systems is in the use of change differential input data the system is tested with 16 documented landslides it can predict 11 of the 16 landslides to be among the 10 most at risk pixels in the area of study which covers 100 km2

geotechnical and landslide aspects in weathered granitoid rock masses serre massif southern calabria italy abstract the weathering processes produce important chemical and physical transformations in rock masses producing a decay of their strength and then stability in this study different methodologies were employed to define the physical mechanical properties and the minero petrographical changes at each grade of weathering useful to determine a geological model of the weathered granitoids involved in mass movements the paper focuses on a multidisciplinary research on the weathering profiles of the paleozoic granitoid rocks surrounding the village of fabrizia located in the serre massif southern calabria italy fabrizia lies on an old erosion surface composed of basement rocks made up of weathered granitoids belonging to the serre massif granitoid complex and overlain by thin eluvial colluvial deposits the tectonic uplift of the area combined with mediterranean climatic conditions both active at least since the quaternary are the main causes of the deep weathering of the plutonic rocks the weathered profiles of the granitoid complex have been studied through field observations borehole explorations with geotechnical tests and seismic surveys coupled to minero petrographical analysis and laboratory tests weathered profiles are mainly composed by rock masses varying from completely weathered and residual soil classes v vi to moderately weathered rocks class iii characterized by a progressive increase of geotechnical properties e g seismic wave velocity rock quality designation internal friction angle uniaxial compressive strength with a decrease of weathering the weathered rocks display a wide variety of mass movement landslide types are rockfalls for the fresher rocks class iii translational slides occur between different weathering degrees classes iv and v and rotational slides dominate at the top of the slopes and generally involve the weathering grades from class iv to classes v vi the shallow horizons are composed of thin eluvial colluvial deposits and more weathered granitoids classes v vi that may generate dangerous debris flows or debris avalanches during intense and prolonged rainfall the landslide surface is usually at a depth lower than 2 m in the debris flow type while deeper landslides depth 2 m are rotational and translational types with sliding surfaces occurring mainly in the transition between the classes iv and v the field survey coupled to geotechnical geophysical and minero petrographical data allowed the recognition of the different weathered horizons and relative geotechnical properties useful to the reconstruction of the reliable geological model the model represents an important support for the study of the landslide processes and for a sustainable management of the territory the used approach provided results to set a general reference framework for establishing more precise correlations between mass movement phenomena and weathering processes

static mass balance sensitivity of arctic glaciers and ice caps using a degree day approach the purpose of this study is to enhance our understanding of the response of glaciers to climate change global sea level is affected by changes in glacier ice volume and melt water from glaciers is a principal water source in many regions this study applies glacier mass balance modelling with varying complexity and spatial resolution ranging from individual glaciers to regional and global assessments of glacier mass losses glaciers located in maritime environments generally show considerably higher mass balance sensitivities than those in continental settings on average an assumed increase in annual precipitation of 10 tends to offset the effect of an annual temperature change of 1 k by roughly 20 two case studies at storglaciaren sweden and hofsjokull iceland involve model results of future mass balance change and glacier melt induced changes in runoff applying a temperature and precipitation scenario for iceland in 2050 results in increased total runoff from hofsjokull by roughly one third and results emphasize the role of the firn layer in delaying water flow through glaciers yielding a redistribution of discharge within the year based on a global gridded data set of glacierized area the sea level equivalent from all mountain glaciers and ice caps outside the ice sheets in greenland and antarctica during 1961 2004 caused by changes in temperature and precipitation is estimated to be 0 58 0 34 mm a 1 the mountain glaciers and ice caps around antarctica alone contribute almost 40 of the global estimate and hence their contribution is considerably larger than previously assumed

catastrophic mass movement of 1998 monsoons at malpa in kali valley kumaun himalaya india abstract a devastating landslide on 18 august 1998 near malpa village in kali valley of higher kumaun himalaya killed 221 persons the landslide was a complex rock fall debris flow the mass movement generated around one million cubic metres of debris and partially blocked the kali river malpa gad a tributary of kali being blocked completely the rock mass failed primarily due to the near vertical slopes hanging over the valley along joints the formation of structural wedges along the free face the sheared rock mass due to the close proximity of major tectonic planes and the enhanced pore water pressure due to prolonged heavy precipitation in the preceding days the mesoscopic shear zone exhibiting ramp and flat structure in quartzites shows a southward thrust movement that might have generated shear stress in the rocks the slide clearly demonstrates the distressed state of the rock mass in the himalayan region due to the ongoing northward drift of the indian plate

size distribution of loess slides in relation to local slope height within different slope morphologies abstract loess slides are widespread and dangerous gravity induced surface processes on the loess plateau of north central china the local slope height and slope morphology have been considered as important conditioning factors for landslide susceptibility mapping however the quantitative relationship between landslide size and local slope height within different slope morphologies is not very clear in this study an inventory of 155 loess slides was developed based on detailed field investigation and remote sensing image interpretation statistical analysis and gis were applied to find the quantitative relationships between the size of these loess slides and local slope height in different types of slope morphologies the analysis shows that the relationship between the loess slides volume and area exhibits a similar trend within different types of slope morphologies in addition the analysis demonstrated that loess slides are more frequent on local slope height from 40 to 100 m stepped slopes with higher pore water pressure are prone to sliding and approximate 34 19 of total loess slides occur in these stepped slopes moreover the analysis shows that the mean loess slide area and volume rapidly increase with increasing local slope height furthermore the result underlines the fact that both the local slope height and the slope morphology are two fundamental factors that control the occurrence as well as size distribution of loess slides the loess slide size remarkably increases with increasing local slope height within every type of slope morphologies these findings indicate that local slope height can limit the loess slide size and their spatial extent moreover we quantified the correlation between the loess slide size and local slope height using power law form and the scaling exponents of the correlations are different within different slope morphologies

gis based landslide susceptibility mapping for a problematic segment of the natural gas pipeline hendek turkey a segment of natural gas pipeline was damaged due to landsliding near hendek re routing of the pipeline is planned but it requires the preparation of a landslide susceptibility map in this study the statistical index wi and weighting factor wf methods have been used with gis to prepare a landslide susceptibility map of the problematic segment of the pipeline for this purpose thematic layers including landslide inventory lithology slope aspect elevation land use land cover distance to stream and drainage density were used in the study area landslides occur in the unconsolidated to semi consolidated clayey unit and regolith the wf method gives better results than the wi method lithology is found to be the most important aspect in the study area based on the findings obtained in this study the unconsolidated to semi consolidated clayey unit and alluvium should be avoided during re routing agricultural activities should not be allowed in the close vicinity of the pipeline

multi criteria evaluation for landslide hazard zonation by integrating remote sensing gis and field data in north kashmir himalayas j k india landslides are one of the major natural hazards that are experienced in hilly terrains all over the world and himalayas are no exception to this though primarily attributed to natural causes landslides are increasing in frequency and magnitude due to anthropogenic disturbances this has resulted in enormous damage to both life and property hence identification of landslide prone areas is essential for safer strategic planning of future developmental activities a landslide hazard zonation lhz map is generated by multi criteria evaluation mce of various responsible factors like slope drainage land use and land cover lithology soil and aspect which are weighted on the basis of their relative contribution to the occurrence of landslides these weights are normalized such that the sum of normalized weights is equal to unity the study area is divided into five zones based on the deciles of the normalized weights the results reveal that 40 of the area falls under high lhz which needs immediate engineering and agronomic measures the mce model presented in this study could be utilized for other mountainous regions in general and himalayas in particular

geophysical characterization of a landslide site in the himalayan foothill region abstract a combination of electrical resistivity seismic refraction and spectral analysis of surface waves sasw have been used for the characterization of a landslide site in the mohand area of the himalayan foothills near dehradun primary attention was drawn to the determination of the thickness of the landslide body its possible slip surface and evaluation of hydrogeological conditions related to the occurrence of a landslide in the study area this was accomplished by defining the electrical resistivity and seismic wave velocity of the different lithological units validation of geophysical investigations was performed by conducting a geophysical survey near boreholes and subsequently correlating geophysical parameters values with the formation known from borehole data and other geological information available in the himalayan foothills region results obtained from geophysical investigation suggest that the slip surface of the landslide approximately coincides with the top of the saturated gravely soils indicating a change in the hydrogeological conditions at the landslide site after the event the study shows that the electrical resistivity seismic refraction and sasw in combination could be an effective tool for locating a landslip surface

characteristics of rain induced landslides in the indian himalaya a case study of the mandakini catchment during the 2013 flood abstract landslides triggered by monsoon rainfall are a recurring hazard that lead to loss of life and cause enormous property and infrastructure damage in the indian himalaya this study is focused on understanding the role of extreme rainfall and physical factors in causing landslides in the indian himalaya particularly in the mandakini catchment where an enormous landslide and flood disaster occurred in june 2013 following a two day extreme rainfall event results indicate that sub daily extreme rainfall depths causing landslides vary with elevation across the catchment antecedent rainfall six days prior to the extreme rainfall event was found to have substantial depths that could have primed the area for landslides except for aspect of slopes the causative factors including land use land cover lithology elevation slope river network distance to roads and total extreme rainfall as a triggering factor were found to be statistically significant in causing landslides in the catchment the final product of the study is a new landslide susceptibility map that better delineates the landslide prone regions in the disaster prone mandakini catchment after the june 2013 extreme rainfall event the map was prepared using logistic regression that shows medium and high susceptibility zones at upper sections of the catchment as well as along the mandakini river and its tributaries where major sacred shrines tourist spots and human establishments are located

derivation and analysis of a complete modern date glacier inventory for alaska and northwest canada we present a detailed complete glacier inventory for alaska and neighboring canada using multi sensor satellite data from 2000 to 2011 for each glacier we derive outlines and 51 variables including center line lengths outline types and debris cover we find 86 723 km 2 of glacier area 27 109 glaciers 0 025 km 2 similar to 12 of the global glacierized area outside ice sheets of this area 12 0 is drained by 39 marine terminating glaciers 74 km of tidewater margin and 19 3 by 148 lake and river terminating glaciers 420 km of lake river margin the overall debris cover is 11 with considerable differences among regions ranging from 1 4 in the kenai mountains to 28 in the central alaska range comparison of outlines from different sources on 2500 km 2 of glacierized area yields a total area difference of similar to 10 emphasizing the difficulties in accurately delineating debris covered glaciers assuming fully correlated systematic errors uncertainties in area reach 6 for all alaska glaciers but further analysis is needed to explore adequate error correlation scales preliminary analysis of the glacier database yields a new set of well constrained area length scaling parameters and shows good agreement between our area altitude distributions and previously established synthetic hypsometries the new glacier database will be valuable to further explore relations between glacier variables and glacier behavior

on the damage caused by the chamoli earthquake of 29 march 1999 abstract the moderate magnitude chamoli earthquake which occurred on 29 march 1999 in the alkananda river valley region of garhwal himalaya caused considerable loss to human life and property from a systematic field survey of the damage conducted for five continuous days immediately after the earthquake the following could be noted i the consequences of the damage are most pronounced near the main central thrust mct ii the maximum damage is between chamoli and the 40 km2 area to the its north and was probably caused by major uplift iii distinct radial cracks accompanied by considerable ground subsidence due to this earthquake could be observed north of the completely devastated village of mawana situated 4 km northwest of chamoli iv the intensity of damage in the meisoseismal zone covering approx 580 km2 area suggests a value of 0 2 g for the ground acceleration

interpretation of observed ground level changes due to the 1905 kangra earthquake northwest himalaya the kangra earthquake of 1905 in the northwest himalaya was the first indian earthquake for which coseismic ground elevation changes were measured through repeat precision levelling the levelling une from saharanpur to mussoorie via dehra dun was situated near the southeastern extremity of the nw se trending meizoseismal area maximum uplift of 14 3 cm was measured at a bench mark in dehra dun some details of the levelling data having been published recently data for eight bench marks were considered for interpretation in this study in principle these are sufficient for us to estimate eight parameters of a rectangular rupture buried in a homogeneous poisson solid but because of some uncertainties regarding the bench mark positions and also the relatively small amounts of uplift measured at the bench marks we have preferred to use the data as a means to check the reasonableness of rupture models proposed on other grounds rather than to propose a new model independently the observed elevation changes are not in accord with the view that the kangra earthquake was caused by a single 100 km long rupture along the shahpur mandi sector of the northwest himalaya however the data can be explained if in addition a second smaller rupture extending on either side of the levelling une near dehra dun is assumed the data can also be explained if the rupture during the earthquake had 1 a length of 280 km parallel to the general strike of the himalaya from around kangra up to a short distance about 10 15 km northwest of the levelling une near dehra dun 2 a breadth of 80 km perpendicular to the strike of the himalaya 3 a northeasterly dip of about 5 and 4 a depth of 10 15 km along its sw edge finally the elevation data rule out any role for the main boundary thrust in the occurrence of the kangra earthquake this major tectonic feature demarcating the geological boundary between the outer and the lesser himalaya thus appears to be unimportant in the current seismotectonics of the region and the subduction of the indian lithospheric plate under the mountains

statistical evaluation of the effect of earthquake with other related factors on landslide susceptibility using the watershed area of shihmen reservoir in taiwan as a case study landslide susceptibility evaluation is one of the most important issues in watershed management after an earthquake the landslide susceptibility decreases functionally with increases in the distance from the epicenter under the same rainfall intensity landslides are more likely to occur in an area where earthquakes occur more frequently however the questions of how much an earthquake should be weighted and how to evaluate the effects of an earthquake still need to be studied to understand how earthquakes affect rainfall triggered landslides the horizontal peak ground acceleration pga data from the central weather bureau seismic network is used as the earthquake factor and combined with other factors to determine the weight of earthquakes in landslide susceptibility using logistic regression the results indicate that the ability of landslide prediction is better when considering the earthquake factor this study also proved that although there are no co seismic landslides after earthquakes in the study area the earthquake factor is still required to increase the model accuracy pga has been described as a usable factor in areas with frequent earthquakes and high geological activity when using historical data to evaluate landslide susceptibility the earthquake factor should be taken into consideration to prevent errors

degree day glacier mass balance modelling with applications to glaciers in iceland norway and greenland a degree day glacier mass balance model is applied to three glaciers in iceland norway and greenland for which detailed mass balance measurements are available over a period of several years model results are in good agreement with measured variations in the mass balance with elevation over the time periods considered for each glacier in addition the model explains 60 80 of the year to year variance in the elevation averaged summer season mass balance measurements on the glaciers using a single parameter set for each glacier the increase in ablation on the glaciers due to a warming of 2 c is predicted to range from about 1 m w e year 1 at the highest elevations to about 2 5 m w e year 1 at the lowest elevations predicted changes in the winter balance measured between fixed date are relatively small except at the lowest elevations on the icelandic and norwegian glaciers where the winter balance is significantly reduced equilibrium line altitudes are raised by 200 300 m on the icelandic and norwegian glaciers except at the highest elevations the winter balance of the icelandic and norwegian glaciers is predicted to decrease even if the warming is accompanied by a 10 increase in the precipitation no firm evidence of a climate related variation in the degree day factors or in the temperature lapse rate on the same glacier could be found the model furthermore reproduces large variations in the mass balance with elevation and from year to year on each glacier using the same parameter set we assume therefore that these parameters will not change significantly for the climate scenarios considered here

landslide susceptibility assessment in the izmir west anatolia turkey city center and its near vicinity by the logistic regression method a landslide susceptibility assessment for izmir city western turkey which is the third biggest city of turkey was performed by a logistic regression method a database of landslide characteristics was prepared using detailed field surveys the major landslides in the study area are generally observed in the field dominated by weathered volcanics and 39 63 of the total landslide area is in this unit the parameters of lithology slope gradient slope aspect distance to drainage distance to roads and distance to fault lines were used as variables in the logistic regression analysis the effect of each parameter on landslide occurrence was assessed from the corresponding coefficients that appear in the logistic regression function on the basis of the obtained coefficients lithology plays the most important role in determining landslide occurrence and distribution slope gradient has a more significant effect than the other geomorphological parameters such as slope aspect and distance to drainage using a predicted map of probability the study area was classified into five categories of landslide susceptibility very low low moderate high and very high whereas 49 65 of the total study area has very low susceptibility very high susceptibility zones make up 11 69 of the area

assessment of shallow landslide susceptibility using artificial neural networks in jabonosa river basin venezuela landslides represent one of the most morphodynamic processes that affect the steep lands and may destroy croplands as well as urban and industrial development landslide risk analysis can help government agencies to select suitable locations for development schemes and plan mitigation measures in unstable landslide prone areas this study describes an approach for assessing the landslide risk potential mainly for shallow landslides with reference to jabonosa river basin in the venezuelan andes using artificial neural networks anns specifically a multilayer perceptron with backpropagation learning algorithm the approach developed uses a wide range of parameters of slope instability derived from digital elevation models dems remote sensing imagery and documentary data around 90 overall accuracy produced by the ann technique were found promising for future studies in landslide susceptibility zonation

use of fuzzy relations to produce landslide susceptibility map of a landslide prone area west black sea region turkey abstract preparation of landslide susceptibility maps is important for engineering geologists and geomorphologists however due to complex nature of landslides producing a reliable susceptibility map is not easy for this reason many procedures have been used to produce such maps in this study a new attempt is tried to produce landslide susceptibility map of a part of west black sea region of turkey to obtain the fuzzy relations for producing the susceptibility map a landslide inventory database is compiled by both field surveys and airphoto studies a total of 266 landslides are identified in the study area and dominant mode of failure is rotational slide while the other mode of failures are soil flow and shallow translational slide the landslide inventory and the parameter maps are analyzed together using a computer program fullsa developed in this study the computer program utilizes the fuzzy relations and produces the landslide susceptibility map automatically according to this map 9 6 of the study area is classified as very high susceptibility 10 3 as high susceptibility 8 9 as moderate susceptibility 27 5 as low susceptibility and 43 8 as very low susceptibility or nonsusceptible areas the prediction performance of the susceptibility map is checked by considering actual landslides in the study area for this purpose strength of the relation rij and the root mean square error rmse values are calculated as 0 867 and 0 284 respectively these values show that the produced landslide susceptibility map in the present study has a sufficient reliability it is believed that the approach employed in this study mainly prevents the subjectivity sourced from the parameter selection and provides a support to improve the landslide susceptibility mapping studies

landslide susceptibility mapping along kolli hills ghat road section india using frequency ratio relative effect and fuzzy logic models this article emphasizes landslide susceptibility mapping along ghat road of kolli hills tamil nadu india using frequency ratio relative effect and fuzzy gamma operator models with the help of remote sensing data and gis technique the purpose of the study is to generate compare and validate landslide susceptibility zones landslide inventory was done with data collected from the state highways department there are nine landslide influencing parameters such as slope gradient slope aspect slope curvature relief lithology land use and land cover proximity to road proximity to drainage and proximity to lineament analyzed with help of topo map existing geology map and satellite data to produce landslide susceptibility maps landslide susceptibility maps were generated by calculating relationship between the landslide influencing factors with past landslide locations using frequency ratio relative effect and fuzzy gamma operator models these landslide susceptibility maps were verified and compared using the existing landslide inventory data the prediction accuracy of frequency ratio model was 87 93 for fuzzy gamma operator model was 87 33 and for relative effect model it was 85 26 out of which the frequency ratio model provide maximum prediction accuracy on landslide susceptibility

terrain based mapping of landslide susceptibility using a geographical information system a case study this paper deals with the development of a technique for mapping landslide susceptibility using a geographical information system gis with particular reference to landslides on natural terrain the method has been applied to lantau island the largest outlying island within the territory of hong kong landslide susceptibility in the study area is related to a number of terrain variables viz lithology slope gradient slope aspect elevation land cover and distance to drainage line multiple correspondence analysis mca was carried out to generate the principal axes that are linear combinations of these terrain variables using occurrence data of landslides and terrain variables a gis is used to project the values of the principal axes and subsequently to relate these principal axes to landslide susceptibility by logistic regression modeling the spatial landslide susceptibility response in the study area can then be obtained by applying this logistic regression model to the study area the results from this study indicate that such a gis based model is useful and suitable for the scale adopted in this study

validation of high resolution grace mascon estimates of glacier mass changes in the st elias mountains alaska usa using aircraft laser altimetry we acquired center line surface elevations from glaciers in the st elias mountains of alaska northwestern canada using aircraft laser altimetry during 2000 05 and compared these with repeat measurements acquired in 2007 the resulting elevation changes were used to estimate the mass balance of 32 900 km 2 of glaciers in the st elias mountains during september 2003 to august 2007 yielding a value of 21 2 3 8gta 1 equivalent to an area averaged mass balance of 0 64 0 12 m a 1 water equivalent w e high resolution 2 arc degrees spatial and 10 day temporal gravity recovery and climate experiment grace mass balance estimates during this time period were scaled to glaciers of the st elias mountains yielding a value of 20 6 3 0 gt a 1 or an area averaged mass balance of 0 63 0 09 m a 1 w e the difference in balance estimates altimetry minus grace was 0 6 4 8 gta 1 well within the estimated errors differences likely resulted from uncertainties in subgrid sampling of the grace mass concentration mascon solutions and from errors in assigning an appropriate near surface density in the altimetry estimates the good correspondence between grace and aircraft altimetry data suggests that high resolution grace mascon solutions can be used to accurately assess mass balance trends of mountain glacier regions that are undergoing large changes

assessment of landslide susceptibility on the natural terrain of lantau island hong kong steep terrain and the high frequency of tropical rainstorms make landslide occurrence on natural terrain a common phenomenon in hong kong for example more than 800 slope failures were triggered by a rainstorm in november 1993 on lantau island hong kong maps of recent landslides interpreted from aerial photographs in combination with a geographical information system were used to evaluate the frequency and distribution of landslides with particular reference to such physical parameters as lithology slope gradient slope aspect elevation vegetation cover and proximity to drainage line all of which are considered to be influential in the occurrence of landslides a stepwise logistic regression model was obtained between landslide susceptibility and the above mentioned physical parameters the study area has been classified into five classes of relative landslide susceptibility namely very low low moderate high and very high based on this methodology

the glaciers climate change initiative methods for creating glacier area elevation change and velocity products glaciers and their changes through time are increasingly obtained from a wide range of satellite sensors due to the often remote location of glaciers in inaccessible and high mountain terrain satellite observations frequently provide the only available measurements furthermore satellite data provide observations of glacier characteristics that are difficult to monitor using ground based measurements thus complementing the latter in the glaciers cci project of the european space agency esa three of these characteristics are investigated in detail glacier area elevation change and surface velocity we use a data from optical sensors to derive glacier outlines b digital elevation models from at least two points in time c repeat altimetry for determining elevation changes and d data from repeat optical and microwave sensors for calculating surface velocity for the latter the two sensor types provide complementary information in terms of spatio temporal coverage while c and d can be generated mostly automatically a and b require the intervention of an analyst largely based on the results of various round robin experiments multi analyst benchmark studies for each of the products we suggest and describe the most suitable algorithms for product creation and provide recommendations concerning their practical implementation and the required post processing for some of the products area velocity post processing can influence product quality more than the main processing algorithm

the dynamic response of the greenland and antarctic ice sheets to multiple century climatic warming new calculations were performed to investigate the combined response of the greenland and antarctic ice sheets to a range of climatic warming scenarios over the next millennium use was made of fully dynamic 3d thermomechanic ice sheet models which were coupled to a two dimensional climate model the experiments were initialized with simulations over the last two glacial cycles to estimate the present evolution and were subsequently forced with temperature scenarios resulting from greenhouse emission scenarios which assume equivalent co2 increases of two four and eight times the present 1990 a d value by the year 2130 a d and a stabilization after that the calculations brought to light that during the next century short term effect the background evolution trend would dominate the response of the antarctic ice sheet but would be negligible for the greenland ice sheet on that timescale the greenland and antarctic ice sheets would roughly balance one another for the middle scenario similar to the ipcc96 is92a scenario with respective contributions to the worldwide sea level stand on the order of about 610 cm on the longer term however both ice sheets would contribute positively to the worldwide sea level stand and the most important effect would come from melting on the greenland ice sheet sensitivity experiments highlighted the role of ice dynamics and the height massbalance feedback on the results it was found that ice dynamics cannot be neglected for the greenland ice sheet not even on a century timescale but becomes only important for antarctica on the longer term the latter is related to an increased outflow of ice into the ice shelves and to the grounding line retreat of the west antarctic ice sheet which are both found to be sensitive to basal melting below ice shelves and the effective viscosity of the ice shelves stretching parameters to their limits yielded a combined maximum rate of sea level rise of 85 cm century21 of which 60 cm would originate from the greenland ice sheet alone

landslide hazard mapping based on geological attributes abstract a landslide susceptibility zoning technique is proposed and has been tested in a catchment area of 317 km 2 along the aglar river a tributary of the river yamuna in the himalayas the aglar catchment is characterised by varied rock types mostly sedimentary an active fault landslides moderate to intense seismic activity and moderate human influence very little is known about this terrain except for one previous study this study focusses on the relationship between the terrain parameters and landslide hazard mapping a landslide susceptibility map is presented which can serve as first generation map on which subsequent detailed information can be incorported it is the first map of this kind from the himalayas based on quantitative evaluation of geomorphological and geological parameters on a classified terrain database map the study is in two stages first the terrain has been classified into several homogeneous patterns followed by small physiographic units which are uniform in their characteristics throughout second each unit acquires a score from a rating system based on the degree of mutual relationship between landslides and geological attributes such as slope distance from fault relief dip slope relationship etc each of which has been given weighting according to the strength of this relationship the aim is to frame a practical database system rationally which can be imported into a geographical information system for rapid digital handling of the data a positive relationship established between landslide and sediment yield indicates that long term sediment production in the catchment area comes from the ongoing geological and geomorphological activity the work may have applications in various parts of the himalayas especially the ungauged and unknown catchments falling in similar geological areas and latitudes

landslide zoning in a part of the garhwal himalayas the himalayas are undergoing constant rupturing in the thrust belt zone in the garhwal himalayas due to which earthquake and mass movement activity is triggered these processes of mass movement and landslides have been constantly modifying the landscape landslides are one of the indicators of the geomorphological modifications taking place in this active and fragile terrain this work is aimed at providing another example of landslide susceptibility mapping based on geological and geomorphological attributes the data collected from aerial photographs topographic sheets and the image suggests that there is a correlation between the distribution of landslides and some of the geological and geomorphological factors for example the distance from an active fault relative relief and slope parameters like factor of safety altitude relief slope and the distance from the fault lineament have been included in the study a rating system has been applied to the factors for arriving at a quantitative estimate of landslide susceptibility for each physiographic unit since terrain classification forms the foundation of this work the entire study can be grouped into two sequential activities 1 the terrain classification and 2 landslide susceptibility mapping the result is the landslide susceptibility zoning map presented the landslides have not been classified with respect to time and may represent the final result of the on going geological geomorphological and seismic activity since the holocene period or late pleistocene time when the glaciers retreated

integrating physical and empirical landslide susceptibility models using generalized additive models physically based models are commonly used as an integral step in landslide hazard assessment geomorphic principles can be applied to a broad area resulting in first order assessment of landslide susceptibility new techniques are now available that may result in the increased accuracy of such models we investigate the possibility to enhance landslide susceptibility modeling by integrating two physically based landslide models the factor of safety fs and the shallow stability model shalstab with traditional empirical statistical methods that utilize terrain attribute information derived from a digital elevation model and land use characteristics related to forest harvesting the model performance is measured by the area under the receiver operating characteristic curve auroc and sensitivity at 90 and 80 specificity both estimated by bootstrap resampling our study examines 278 landslide initiation points in the klanawa watershed located on vancouver island british columbia canada we use a generalized additive model gam and a logistic regression model glm combining physical landslide models terrain attributes and land use data and gams and glms using only subsets of these variables in this study all empirical and combined physical empirical models outperform the physically based models with gams often performing significantly better than glms the strongest predictive performance is achieved by the gams using terrain attributes in combination with land use data variables representing physically based models do not significantly improve the empirical models but they may allow for a better physical interpretation of empirical models also based on bootstrap variable selection frequencies land use data fs slope and plan profile curvature are relatively the most important predictor variables

comparison of thermal structure and evolution between neighboring subarctic glaciers 1 the distribution of cold and temperate ice within glaciers and ice sheets affects processes relevant to englacial and basal hydrology sliding and material rheology thermal regimes in turn are shaped by glacier and ice sheet dynamics as well as environmental setting we investigate the thermal structures of two small 7 km2 neighboring glaciers in the st elias mountains of southwestern yukon canada using ice penetrating radar and borehole temperature measurements our data reveal polythermal regimes in both glaciers that are strongly influenced by accumulation zone meltwater entrapment suggesting a climatic control on thermal structure differences in hypsometry and glacier dynamics nevertheless result in observed variations in the distribution of temperate ice between the two sites experiments with a thermomechanically coupled flow band model corroborate the strong control of meltwater entrapment on thermal structure and suggest a generally minimal role for strain heating an exception to this occurs where localized basal sliding produces lateral shearing and thus enhanced heat generation time dependent model simulations suggest that the future thermal evolution of the two glaciers may differ and therefore simple parameterizations of thermal response based on regional climate may not capture realistic variability between individual glaciers despite these differences both glaciers are ultimately expected to become fully cold prior to disappearing under negative mass balance conditions

a back propagation network for the assessment of susceptibility to rock slope failure in the eastern portion of the southern cross island highway in taiwan an assessment of the susceptibility to rock slope failure by means of a back propagation network is proposed for the eastern portion of the southern cross island highway in taiwan the model was developed on the basis of six influence parameters of rock slope instability which include the rock type slope aspect slope angle joint set number joint spacing and bedding slope relationship the values of these influence parameters were used as inputs for the network and were classified as nominal scales in terms of binary numbers while the state of failure non failure of a given slope was assumed to be the output variable data on a total of 170 slopes along the highway was fed into the network for learning according to the outputs of the network the susceptibility to rock slope failure is categorized into four levels namely low medium low medium and high which are mapped along the highway three highly susceptible regions are found which can be viewed as hazardous sections requiring cautionary measures moreover the proposed model can be used as a tool for determining the possible state of an unfamiliar rock slope in the context of devising management strategies to be applied to the investigated portion of the highway

landslide susceptibility mapping of the slopes in the residual soils of the mengen region turkey by deterministic stability analyses and image processing techniques abstract the aim of the present study is to prepare a landslide susceptibility map of a region of about 120 km2 between gokcesu and pazarkoy around mengen nw turkey at approximately 10 km north of the north anatolian fault zone where frequent landslides occur for this purpose mechanisms of the landslides were studied by two dimensional stability analyses together with field observations and the parameters controlling the development of such slides were identified field observations indicated that the failures generally developed within the unconsolidated and or semiconsolidated soil units in forms of rotational successive shallow landslides within the weathered zone in mengen cukurca and sazlar formations although consisting of residual soils capak and gokdag formations do not exhibit landslides as the natural slopes formed on these do not exceed the critical slope angles statistical evaluations and distribution of the landslides on the topographical map showed that such parameters as cohesion angle of internal friction slope relative height orientation of slopes proximity to drainage pattern vegetation cover and proximity to major faults were the common features on the landslides digital images were obtained to represent all these parameters on gray scale on the spot image and on the digital elevation model dem of the area using image processing techniques soil mechanics tests were carried out on 36 representative samples collected from different units and parameters were determined for two dimensional stability analyses basing on sensitivity approach and for the preparation of digital shear strength map in order to determine the critical slope angle values for the residual soils a series of sensitivity analyses were realized by using two dimensional deterministic slope stability analyses techniques for varying values of cohesion angle of internal friction and slope height along with varying saturation conditions according to the results of the sensitivity analyses the mengen formation was found to be most susceptible unit to landslides covering about 33 5 of the region studied in terms of surface area the distribution of the critical slopes were determined by superimposing the critical slope values from sensitivity analyses on slope map of the study area on the other hand iso cohesion and iso friction maps were produced by locating the values of cohesion and internal friction angles in a geographic coordinate system such that they coincide with sample locations on the dem and by further interpolation of the values concerned the pixel values were evaluated in gray scale from 0 to 255 0 representing the lowest pixel value and 255 representing the highest sensitivity analyses on cohesion and angle of internal friction to investigate the effects of these parameters only on stability revealed that cohesion was effective at a rate of 70 by itself while angle of internal friction alone controlled the stability by a rate of 30 the iso cohesion and iso friction maps previously obtained were digitally combined in these rates and a shear strength map was prepared the geographic setting of the study area is such that northern slopes usually receive dense precipitation in relation to this fact about 42 of the landslides are due north thus a slope orientation map was prepared using the dem and slopes facing north were evaluated as being more susceptible to sliding proximity to the drainage pattern was another important factor in the evaluation as streams could adversely affect the stability by either eroding the toe or saturating the slope or both when considered together in conjunction with the field observations faults and landslides showed a close association in the area about 88 of the landslides were detected within an area closer than 250 m to major faults therefore a main discontinuity map was produced using the spot image of the region and proximity to major faults was evaluated as a parameter as most of the landslides developed in areas where the vegetation was rather sparse a vegetation cover map was therefore obtained from the spot image and the areas with denser vegetation were considered to be less susceptible to sliding with respect to the areas with less or no vegetation having prepared the maps accounting for the distribution of critical slopes shear strength properties relative height slope angle orientation of the slopes vegetation cover proximity to the drainage pattern geographic corrections were carried on each of these and a potential failure map was obtained for the residual soils by superimposing all these maps next a classification was performed on the final map and five relative zones of susceptibility were defined when compared with this map all of the landslides identified in the field were found to be located in the most susceptible zone the performance of the method used in processing the images appears to be quite high the zones determined on the map being the zones of relative susceptibility

assessment of landslide susceptibility for a landslide prone area north of yenice nw turkey by fuzzy approach regional landslide susceptibility assessments pose complex problems to solve these problems numerous approaches such as statistical analysis geotechnical engineering approach geomorphologic approach and fuzzy logic have been employed however all the available methods for regional landslide susceptibility assessments have some uncertainties due to a lack of knowledge and variability minimizing these uncertainties provides realistic approaches use of the fuzzy logic approach to produce a landslide susceptibility map of a landslide prone area in nw turkey is the main purpose of the present study for this purpose the study includes five main stages these being the preparation of a landslide inventory of the study area the application of factor analysis the extraction of fuzzy if then rules the use of a geographical information system and the control of the reliability of the resulting landslide susceptibility map slope angle slope aspect land use weathering depth water conditions and topographical elevation were considered as landslide conditioning factors for the study area a total of 23 if then rules was extracted from the field data employing these rules fuzzified index maps representing each parameter were obtained finally combining these maps the landslide susceptibility map of the area was prepared when compared with the landslide susceptibility map the landslides identified in the area were found to be located in the very high and high susceptibility zones as far as the performance of the fuzzy approach for processing is concerned the images appear to be quite satisfactory the zones determined on the map being zones of relative susceptibility

sustained rapid shrinkage of yukon glaciers since the 1957 1958 international geophysical year 1 glaciers in the yukon nw canada lost 22 of their surface area during the 50 years following the 1957 58 international geophysical year coincident with increases in average winter and summer air temperatures and decreases in winter precipitation scaling these results to ice volume change we obtain a total mass loss of 406 177 gt which accounts for 1 12 0 49 mm of global sea level rise yukon glaciers thinned by 0 78 0 34 m yr 1 water equivalent a regional thinning rate exceeded only by mountain glaciers in patagonia and alaska our scaling analysis suggests the remaining glaciers have the capacity to contribute a further 5 02 mm to global sea level rise

simulating annual glacier flow with a linear reservoir model 1 in this paper we present a numerical simulation of the observation that most alpine glaciers have reached peak velocities in the early 1980s followed by nearly exponential decay of velocity in the subsequent decade we propose that similarity exists between precipitation and associated runoff hydrograph in a river basin on one side and annual mean specific mass balance of the accumulation area of alpine glaciers and ensuing changes in ice flow on the other side the similarity is expressed in terms of a linear reservoir with fluctuating input where the year to year change of ice velocity is governed by two terms a fraction of the velocity of the previous year as a recession term and the mean specific balance of the accumulation area of the current year as a driving term the coefficients of these terms directly relate to the timescale the mass balance altitude profile and the geometric scale of the glacier the model is well supported by observations in the upper part of the glacier where surface elevation stays constant to within 5 m over a 30 year period there is no temporal trend in the agreement between observed and modeled horizontal velocities and no difference between phases of acceleration and phases of deceleration which means that the model is generally valid for a given altitude on a given glacier

a linear theory of orographic precipitation a linear theory of orographic precipitation is developed including airflow dynamics condensed water advection and downslope evaporation the formulation extends the widely used upslope model vertically integrated steady state governing equations for condensed water are solved using fourier transform techniques closed form expressions are derived for special cases for more general cases the precipitation field is computed quickly by multiplying the terrain transform by a wavenumber dependent transfer function five length scales are included in the model mountain width a buoyancy wave scale the moist layer depth and two condensed water advection distances the efficiency of precipitation in the model is sensitive to the decay of the forced ascent through the moist layer and to the advection of condensed water downwind into the region of descent the strong influence of horizontal scale on precipitation pattern and amount predicted by the model is discussed the model is illustrated by applying it to the olympic mountains in washington state

application of logistic regression for landslide susceptibility zoning of cekmece area istanbul turkey as a result of industrialization throughout the world cities have been growing rapidly for the last century one typical example of these growing cities is istanbul the population of which is over 10 million due to rapid urbanization new areas suitable for settlement and engineering structures are necessary the cekmece area located west of the istanbul metropolitan area is studied because the landslide activity is extensive in this area the purpose of this study is to develop a model that can be used to characterize landslide susceptibility in map form using logistic regression analysis of an extensive landslide database a database of landslide activity was constructed using both aerial photography and field studies about 19 2 of the selected study area is covered by deep seated landslides the landslides that occur in the area are primarily located in sandstones with interbedded permeable and impermeable layers such as claystone siltstone and mudstone about 31 95 of the total landslide area is located at this unit to apply logistic regression analyses a data matrix including 37 variables was constructed the variables used in the forwards stepwise analyses are different measures of slope aspect elevation stream power index spi plan curvature profile curvature geology geomorphology and relative permeability of lithological units a total of 25 variables were identified as exerting strong influence on landslide occurrence and included by the logistic regression equation wald statistics values indicate that lithology spi and slope are more important than the other parameters in the equation beta coefficients of the 25 variables included the logistic regression equation provide a model for landslide susceptibility in the cekmece area this model is used to generate a landslide susceptibility map that correctly classified 83 8 of the landslide prone areas

relative contribution of surface mass balance and ice flux changes to the accelerated thinning of the mer de glace alps over 1979 2008 by subtracting surface topographies from 1979 1994 2000 and 2008 we measured ice thinning rates increasing from 1 m a 1 1979 1994 to more than 4 m a 1 2000 2008 on the tongue of the mer de glace the relative contributions of changes in surface mass balance and ice fluxes to this acceleration in the thinning are estimated using field and remote sensing measurements between 1979 1994 and 2000 2008 surface mass balance diminished by 1 2 m w e a 1 mainly because of atmospheric warming mass balance changes induced by the growing debris covered area and the evolving glacier hypsometry compensated each other meanwhile the mer de glace slowed down and the ice fluxes through two cross sections at 2200 m a s l and 2050 m a s l decreased by 60 between 1979 1994 and 2000 2008 two thirds of the increase in the thinning rates was caused by reduced ice fluxes and one third by rising surface ablation however those numbers need to be interpreted cautiously given our inability to respect mass conservation below our upper cross section an important implication is that large errors would occur if one term of the continuity equation e g surface mass balance was deduced from the two others e g elevation and ice flux changes

glaciers dominate eustatic sea level rise in the 21st century ice loss to the sea currently accounts for virtually all of the sea level rise that is not attributable to ocean warming and about 60 of the ice loss is from glaciers and ice caps rather than from the two ice sheets the contribution of these smaller glaciers has accelerated over the past decade in part due to marked thinning and retreat of marine terminating glaciers associated with a dynamic instability that is generally not considered in mass balance and climate modeling this acceleration of glacier melt may cause 0 1 to 0 25 meter of additional sea level rise by 2100

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