Evaluation of some landslide hazard zonation models in Taleghan basin, Iran

For evaluating some existing landslide hazard zonation models in Taleghan basin, Iran, two important and main data layers so called landslide inventory map and causative factor maps, were prepared. The former one was prepared through aerial photo interpretation, field survey and geological map at scale 1: 100,000. The parameters map, were prepared by making use of existing thematic maps and satellite imageries. All of the prepared data layers were transferred into digital format, for further use in a Geographic Information System (GIS). Moreover, beside the spatial database, an attribute database was created for data storage, management and further analysis. Based on data availability, six models for landslide hazard zonation were applied and evaluated in Taleghan basin in Iran. In order to have a real and impartial evaluation of applied methods, an index called Landslide index was recommended and used. After comparing landslide index in different predicted hazard classes, the conclusion was drawn that the evaluated methods can be categorized and their priority may be identified, but because of weak points of the mentioned methods none of them was quite convenient toproposed. Therefore, making use of an integrated method is recommended. Integrated method means to put all advantages of evaluated methods together and avoid the weak points, in order to have a unique powerful model. Ability of bivariate statistical analysis in zoning very high and very low hazard classes, facilities of experimental method in zoning no hazard and high hazard classes and capability of revised Nilsen method in zoning of medium hazard classes were formed the core of the recommended integrated method. Application of the integrated method in Taleghan basin showed that there is a strong and logical relation between the predicted hazard classes and the landslide index values.