Bulletin of the Geological Society of Malaysia, Volume 43, Dec. 1999, pp. 643 – 651
1Tarbiat Modarres University, Tehran, Iran, P.O. Box 14155-4838
2Res. Assist. of IIEES, Tehran, Iran, P.O. Box 19395-3913
Abstract: Landslide hazard zonation is a method to evaluate the risk where the potential hazard present. The causes of such hazards in an area can usually be identified and predicted. The results of such investigation are normally illustrated as a landslide hazard zonation map where zones of similar potential to landslide can be shown.
Khorshrostam is one of the area most prone to landslide in Iran where more than 13% of its surface area is affected by landslide activity. The landslide damages in the region include the disruption of many villages, farmlands, roads and also the erosion of land surface and consequently increases the rate of sedimentation in the flowing water into the reservoir of the Manjil-dam.
The method for landslide zonation used in this area consists of simple grid unit which includes a combination of factors indicating lithology, slope, tectonic, land use and ground water. The rate of landslide distribution for each factor regarding the grid unit is identified in the form of surface percentage index, SPI, and according to these values the weighing of the involved factors is arranged. A computer program is written on the bases of fuzzy set to calculate the hazard potential index, HPI, for each unit. The combination for units with similar HPI indicates the hazard susceptibility of that unit which is shown as LHZ map.