Landslide susceptibility zonation of the Qazvin-Rasht-Anzali railway track,North Iran

摘要

Landslide Hazard Zonation (LHZ) is a method proposed to evaluate risk where there is thepotential for landslides. Many factors affecting the occurrence of landslides are analysed. The factors contributingto the hazard in an area can usually be identified,results of the investigations frequently being presented as alandslide hazard zonation map which indicates zones of similar risk of landslide occurrence. Qazvin-Rasht-Anzali railway track is one of the areas susceptible to landslides in Iran,and in the area several landslideswere recorded. Landslides caused damage or disturbance to villages,farmlands and railway,exacerbation of thesuperficial erosion and consequently the rate of transportation of sediments. The method of landslide zonationused in this study is based on simple grid unit. The factors contributing to the occurrence of landsliding wereanalysed,including lithology,slope,tectonic and seismotectonic,human activity and hydrology. For each gridunit,the incidence of landsliding and an assessment of the contributory factors were recorded in terms of a surfacepercentage index. A computer program was written to calculate the LHZ for each unit. This was used to prepare theLHZ map. The study area has been classified into five classes of relative landslide hazard,namely,very low,low,moderate,high and very high. The result shows that 7 % of the study area has a high or very high landslide hazard.