landslide hazard evaluation and zonation mapping in mountainous terrain abstract landslide hazard zonation lhz maps are of great help to planners and field engineers for selecting suitable locations to implement development schemes in mountainous terrain as well as for adopting appropriate mitigation measures in unstable hazard prone areas a new quantitative approach has been evolved based on major causative factors of slope instability a case study of landslide hazard zonation in the himalaya adopting a landslide hazard evaluation factor lhef rating scheme has been presented

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

landslides in sado island of japan part ii gis based susceptibility mapping with comparisons of results from two methods and verifications abstract slope instability research and susceptibility mapping is a fundamental component of hazard management and an important basis for provision of measures aimed at decreasing the risk of living with landslides on this basis this paper presents the result of a comprehensive study on slope stability analyses and landslide susceptibility mapping carried out in part of sado island of japan various types of landslides occurred in the island throughout history little is known about the triggering factors and severity of old landslides but for many of the recent slope failures the slope characteristics and stratigraphy are such that ground surfaces retain water perennially and landslides occur when additional moisture is induced during rainfall and snowmelt a range of methods are available in literature for preparation of landslide susceptibility maps in this study we used two methods namely the analytical hierarchy process ahp and logistic regression to produce and later compare two susceptibility maps ahp is a semi qualitative method which involves a matrix based pair wise comparison of the contribution of different factors for landsliding logistic regression on the other hand promotes a multivariate statistical analysis with an objective to find the best fitting model that describes the relationship between the presence or absence of landslides dependent variable and a set of causal factors independent parameters elevation lithology and slope gradient were casual factors in this study the determinations of factor weights by ahp and logistic regression were preceded by the calculation of class weights landslide densities based on bivariate statistical analyses bsa the differences between the ahp derived susceptibility map and the logistic regression counterpart are relatively minor when broad based classifications are considered however with an increase in the number of susceptibility classes the logistic regression map gave more details but the one derived by ahp failed to do so the reason is that the majority of pixels in the ahp map have high values and an increase in the number of classes gives little change in the spatial distribution of susceptibility zones in the middle to verify the practicality of the two susceptibility maps both of them were compared with a landslide activity map containing 18 active landslide zones the outcome was that the active landslide zones do not completely fit into the very high susceptibility class of both maps for various reasons but 70 of these landslide zones fall into the high and very high susceptibility zones of the ahp map while this is 63 in the case of logistic regression this indicates that despite the skewed distribution of susceptibility indices the ahp map was better to capture the reality on the ground than the logistic regression equivalent

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

hydrogeological and geotechnical assessments of the kadifekale landslide area izmir turkey the study area is located in the south of izmir city centre in an area built without planning permission or any overall city plan in this area a number of mass movements occurred in the past and the region is still an active landslide field at present the real sliding factor is geological structure which is made up of hard volcanic rocks overlying soft neogene clayey soils and forms a typical structure prone to sliding unplanned human activities change the hydrogeological and geotechnical stabilities of the geological formations in a negative way rain and water leaking either directly from the mains or septic holes infiltrate into the ground and act as one of the factors in causing landslides it is clearly shown that the irregular urbanization in and around kadifekale is one of the factors contributing to the landslides in the area to prevent the occurrence of landslides in the study area an effective surface and under ground drainage should be established rain and wastewater should be removed from the area by separate systems slopes should be reduced water loving trees should be planted and construction of high rise buildings should be avoided

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

use of an artificial neural network for analysis of the susceptibility to landslides at boun korea the purpose of this study was to develop landslide susceptibility analysis techniques using artificial neural networks and to apply the resulting techniques to the study area of boun in korea landslide locations were identified in the study area from interpretation of aerial photographs and field survey data a spatial database of the topography soil type timber cover geology and land cover was constructed and the landslide related factors were extracted from the spatial database using these factors the susceptibility to landslides was analyzed by artificial neural network methods the results of the landslide susceptibility maps were compared and verified using known landslide locations at another area yongin in korea a geographic information system gis was used to analyze efficiently the vast amount of data and an artificial neural network turned out to be an effective tool to analyze the landslide susceptibility

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

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

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

an objective method to rank the importance of the factors predisposing to landslides with the gis methodology application to an area of the apennines valnerina perugia italy the present work aims at contributing to further our knowledge on the predisposing factors to landslides as well as proposing a method that allows us to weigh up as objectively as possible the influence that the various factors have on landslides in order to construct a realistic map of potential landslide hazards in order to assess the differential incidence of very predisposing factor to landslides maps of the various factors considered were drawn up with the aid of idrisi software 1997 the factors were as follows the distance from faults parallelism between the fractures and the landslide scarps land use lithology distance from the streams orientation and steepness of slopes orientation of layers compared to the slope the global analysis of the different incidence of the factors analyzed on the landslides present in the study area was carried out by comparing the respective maps with that of the scarps in this way the number of pixels forming the scarps which fell into the various classes of the maps was calculated the result thus obtained can form the basis of an objective assignation of the different ratings to be attributed to the various factors under consideration in fact the analysis carried out in this study has shown that the factors act differently and for every factor only some of the classes considered have marked importance

predictive landslide susceptibility mapping using spatial information in the pechabun area of thailand for predictive landslide susceptibility mapping this study applied and verified probability model the frequency ratio and statistical model logistic regression at pechabun thailand using a geographic information system gis and remote sensing landslide locations were identified in the study area from interpretation of aerial photographs and field surveys and maps of the topography geology and land cover were constructed to spatial database the factors that influence landslide occurrence such as slope gradient slope aspect and curvature of topography and distance from drainage were calculated from the topographic database lithology and distance from fault were extracted and calculated from the geology database land cover was classified from landsat tm satellite image the frequency ratio and logistic regression coefficient were overlaid for landslide susceptibility mapping as each factor s ratings then the landslide susceptibility map was verified and compared using the existing landslide location as the verification results the frequency ratio model showed 76 39 and logistic regression model showed 70 42 in prediction accuracy the method can be used to reduce hazards associated with landslides and to plan land cover

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

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

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

the timing of epigenetic gold mineralization on the baie verte peninsula newfoundland canada new evidence from re os pyrite geochronology the absolute timing of epigenetic mineralization including most types of gold deposits is difficult to resolve due to the absence of suitable minerals in veins and replacement zones however gold is commonly closely associated with pyrite and arsenopyrite which may be amenable to re os geochronology providing sufficient re and os are present within them this short paper outlines the use of this method to date two gold deposits in newfoundland using pyrite although the os contents of the pyrites are extremely low 0 1 ppb the os is almost exclusively radiogenic 187os and data are amenable to model age calculations as used in re os molybdenite dating the pyrites from these deposits correspond to low level highly radiogenic sulphides as defined by other studies the stog er tight and pine cove gold deposits yield mean re os model ages of 411 7 ma n 4 and 420 7 ma n 5 respectively which agree with isochron regression of 187os against 187re the re os age for stog er tight is within uncertainty of a previous u pb age from hydrothermal zircon 420 5 ma in spatially related alteration a latest silurian earliest devonian age for the mineralization is consistent with indirect age constraints from some other gold deposits in central newfoundland and suggests a broad temporal link to the mid silurian salinic orogeny however the gold mineralization appears to be younger than most plutonic activity associated with this event the results illustrate the potential value of re os pyrite geochronology in understanding the temporal framework of epigenetic mineralization especially if future improvements in analytical precision and reductions in procedural blanks allow wider application to material with similarly low re and os concentrations

a method for producing digital probabilistic seismic landslide hazard maps abstract the 1994 northridge california earthquake is the first earthquake for which we have all of the data sets needed to conduct a rigorous regional analysis of seismic slope instability these data sets include 1 a comprehensive inventory of triggered landslides 2 about 200 strong motion records of the mainshock 3 1 24 000 scale geologic mapping of the region 4 extensive data on engineering properties of geologic units and 5 high resolution digital elevation models of the topography all of these data sets have been digitized and rasterized at 10 m grid spacing using arc info gis software on a unix computer combining these data sets in a dynamic model based on newmark s permanent deformation sliding block analysis yields estimates of coseismic landslide displacement in each grid cell from the northridge earthquake the modeled displacements are then compared with the digital inventory of landslides triggered by the northridge earthquake to construct a probability curve relating predicted displacement to probability of failure this probability function can be applied to predict and map the spatial variability in failure probability in any ground shaking conditions of interest we anticipate that this mapping procedure will be used to construct seismic landslide hazard maps that will assist in emergency preparedness planning and in making rational decisions regarding development and construction in areas susceptible to seismic slope failure

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

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

analysis of the chiufengershan landslide triggered by the 1999 chi chi earthquake in taiwan abstract a disastrous earthquake rocked taiwan on september 21 1999 with magnitude m l 7 3 and an epicenter near the small town of chi chi in central taiwan the chi chi earthquake triggered landslide on the dip slope at the chiufengershan in this study a review of the topography and geology of this area was followed by field investigations laboratory testing was applied to understand the geomaterial composing the slope then based on a series of limit equilibrium analyses the failure mechanism of this landslide and the risk of the residual slope were studied according to the stability analyses the pre quake slope is quite stable with factor of safety of 1 77 dry to 1 35 full groundwater level explaining why there is no written record of a landslide here for the past 100 years in contrast a back analysis shows that the chi chi earthquake induced dynamic loading is far more than the dip slope can sustain due in part to the short distance to the epicenter a monte carlo type probability analysis suggests that the residual slope is more dangerous than the pre quake slope and needs more attention

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

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

determination and application of the weights for landslide susceptibility mapping using an artificial neural network the purpose of this study is the development application and assessment of probability and artificial neural network methods for assessing landslide susceptibility in a chosen study area as the basic analysis tool a geographic information system gis was used for spatial data management and manipulation landslide locations and landslide related factors such as slope curvature soil texture soil drainage effective thickness wood type and wood diameter were used for analyzing landslide susceptibility a probability method was used for calculating the rating of the relative importance of each factor class to landslide occurrence for calculating the weight of the relative importance of each factor to landslide occurrence an artificial neural network method was developed using these methods the landslide susceptibility index lsi was calculated using the rating and weight and a landslide susceptibility map was produced using the index the results of the landslide susceptibility analysis with and without weights were confirmed from comparison with the landslide location data the comparison result with weighting was better than the results without weighting the calculated weight and rating can be used to landslide susceptibility mapping

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

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

verification of landslide susceptibility mapping a case study a methodology is proposed for mapping susceptibility to landsliding and validating the results heavy rains in late 1996 and early 1997 led to a large number of landslids in the rute sector cordoba southern spain where landslide susceptibility mapping had previously been carried out using a matrix method developed with a geographical information system gis analysis of the distribution of the new landslides or reactivated earlier ones enabled the methodology to be validated by calculating association coefficients and determining the closeness of the match between subsequent field evidence and the previously defined susceptibility levels from the data obtained it can be concluded that the susceptibility mapping effectively explained the spatial distribution of landslides thus providing valuable information on stability conditions over a widespread area copyright 1999 john wiley sons ltd

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

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

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

abandoned stone quarries in and around the izmir city centre and their geo environmental impacts turkey there are 70 abandoned quarries in and around izmir city centre of these quarries 56 are in andesites 2 are in dasitic lavas 4 are in flysch and 8 are in limestones the quarries initially located near the izmir city centre are now within the city centre because of the expansion of the urbanization due to the rapid increase of population geo environmental problems identified in the abandoned quarry sites are slope stability problems such as sliding and toppling geotechnical study of the abandoned stone quarries in and around the city centre of izmir which has been carried out involves the recording and determining the properties of discontinuities for stability assessment of already failed and standing slopes in the quarries using stereographic projection techniques and the statistical evaluation of different types of rock mass movements in these quarries the number of mass movements that had already occurred and are likely to occur in 70 quarries lying in and near izmir have been determined as 84 totally stability analyses of rock slopes have shown that rock falls toppling plane and wedge failure type rock mass movements are more common in the south of izmir bay but toppling type slope failures are more frequent in the north

statistical analysis of landslide susceptibility at yongin korea the aim of this study is to evaluate the susceptibility of landslides at yongin korea using a geographic information system gis landslide locations were identified in the yongin area from interpretation of aerial photographs field surveys and maps of the topography soil type timber cover and geology these data were collected and constructed into a spatial database using gis the factors that influence landslide occurrence such as slope aspect and curvature of topography were calculated from the topographic database texture material drainage and effective soil thickness were extracted from the soil database and type age diameter and density of timber were extracted from the forest database lithology was extracted from the geological database and land use was classified from the landsat tm satellite image landslide susceptibility was analyzed using the landslide occurrence factors by probability and logistic regression methods the results of the analysis were verified using the landslide location data the validation results showed satisfactory agreement between the susceptibility map and the existing data on landslide location the gis was used to analyze the vast amount of data efficiently and statistical programs were used to maintain specificity and accuracy the results can be used to reduce associated hazards and to plan land use and construction

discontinuity controlled probabilistic slope failure risk maps of the altindag settlement region in turkey the evaluation of potential rock slope problems using stereographic projection techniques known as kinematic analysis is one of the most important parts of a slope stability investigation to be carried out in jointed rock media in conventional stereoprojection techniques for the assessment of possible rock slope failures the peak orientations of joints together with the slope geometry and the friction angle of the weakness planes are used other possible joint orientations which may be encountered in the rock media are ignored although they belong to the group of joint peak orientations in this study nearly vertical jointed andesites cropped out at the altindag settlement region in ankara were studied in order to evaluate the relevance of this ignored discontinuity orientation data on slope stability as a result probabilistic risk maps for planar toppling and wedge failures were produced using the kinematic rules and digital elevation model of the study area the comparison of the distribution of the actual failures in the area and the probabilistic risk maps prepared for the study area revealed that all of the identified failures are found to be located in the higher risk zones on the probabilistic risk maps

modeled ocean circulation in nares strait and its dependence on landfast ice cover two simplified ocean simulations are used to study circulation and transport within nares strait the simulations are similar except that one included a coupled sea ice model that effectively established a landfast ice cover throughout the simulation year comparison between the ocean only and ocean ice simulations reveals a systematic change in the current structure reminiscent of the seasonal shift under mobile and landfast ice previously observed in nares strait a surface intensified jet which carries low salinity water along the strait s centerline develops within the ocean only simulation the current structure under landfast ice is characterized by a subsurface jet located along the western side with low salinity surface water distributed along the eastern side of the strait intermediate salinity water is offset to the west in the ice ocean simulation relative to the ocean only simulation while high salinity water 34 8 is constrained to recirculations that are located north and south of a sill in kane basin the simulations combined with an idealized semi analytical model suggest that the structural shift is caused by the surface ekman layer beneath the landfast ice and the associated eastward advection of near surface low salinity water and westward movement of the jet temporal variability in the ocean ice simulation is dominated by the remote response to the time dependent northern boundary conditions in contrast the ocean only simulation favors an instability and additionally responds to local surface wind forcing which enhances the variability within the strait above that imposed at the boundaries this article is protected by copyright all rights reserved

landslide susceptibility mapping in the damrei romel area cambodia using frequency ratio and logistic regression models this study applied tested and compared a probability model a frequency ratio and statistical model a logistic regression to damre romel area cambodia using a geographic information system for landslide susceptibility mapping landslide locations were identified in the study area from interpretation of aerial photographs and field surveys and a spatial database was constructed from topographic maps geology and land cover the factors that influence landslide occurrence such as slope aspect curvature and distance from drainage were calculated from the topographic database lithology and distance from lineament were extracted and calculated from the geology database land cover was classified from landsat tm satellite imagery the relationship between the factors and the landslides was calculated using frequency ratio and logistic regression models the relationships frequency ratio and logistic regression coefficient were overlaid to make landslide susceptibility map then the landslide susceptibility map was compared with known landslide locations and tested as the result the frequency ratio model 86 97 and the logistic regression 86 37 had high and similar prediction accuracy the landslide susceptibility map can be used to reduce hazards associated with landslides and to land cover planning

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