Landslide Susceptibility Mapping by Gis-Based Qualitative Weighting Procedure in Corinth Area

Abstract

Landslide susceptibility mapping refers to a division of the land into zones of varying degree of stability based on an estimated significance of causative factors in inducing the instability. Maps of landslide susceptibility (relative hazard) are usually prepared on regional scales from 1:25.000 - 1:50.000. An advantage of regional studies is that they allow rapid assessment and hence larger areas can be covered in short durations. Factors (data layers) used for the preparation of the landslide susceptibility map were obtained from different sources such as topographic maps, geological maps and satellite images. All the above data layers were converted to raster format in the GIS, each representing an independent variable of a constructed spatial database. Computerization of the database would be necessary to make such analysis possible within an acceptable time frame. According to their relative importance to slope instability in the study area, the various classes of different data layers were assigned weights between 0,0 and 1,0 (collectively adding to 1,0). The overall susceptibility was calculated as an index named SPI (Susceptibility Potential Index), expressing the combination of the different weighted layers into a single map using a certain combination rule. Reclassification of susceptibility scores, based on natural breaks in the cumulative frequency histogram of SPI values, were used to delineate various susceptibility zones namely, very high, high, moderate, low and very low. Verification of results by overlaying susceptibility map and landslide inventory data and adjustment of zone's boundaries was the last stage of the study, allowing the reconsideration in some cases of the weights given

An Improved Information Value Model Based on Gray Clustering for Landslide Susceptibility Mapping

“…Proximity of a fault is also a main predisposing factor for landslides. It is well known that landslides tend to occur in the surrounding area of a fault due to fractures in the rock mass [29,30]. The buffer distance from the faults is used as the indicator.…”

Multi-Criteria Analysis Applied to Landslide Susceptibility Mapping

“…The geologic basement aff ects the formation of soils with diff erent cohesion, strength, texture and permeability and, hence, with distinct geotechnical behavior (Rozos et al 2011); -Distance from lineaments: fault and shear zones are preferential areas for rock mass weathering and, thereby, contribute to reduce the strength parameters of rocks and soil. In general, the smaller the distance from tectonic structures the higher is the probability of landslides occurrence (Foumelis et al 2004;Pourghasemi et al 2012). In this study, only the most prominent lineaments were considered due to data availability limitations.…”

Vulnerability assessment of archaeological sites to earthquake hazard: An indicator based method integrating spatial and temporal aspects

“…Fracturing and shearing of geological formations by active tectonic processes contribute significantly to slope failures since they are associated with extensive fractured zones and steep relief morphology. Landslide susceptibility studies in Greece are characterised by a variety of classes and linear ratings for this factor [Foumelis et al 2004, Ladas et al 2007, Rozos et al 2011, Kouli et al 2014. However, for this study the classification and scores by Ladas et al [2007] are applied since the classes are distributed in a way that express satisfactorily the mean tectonic shear attenuation with distance.…”