Landslide Hazard Zoning at the Cheragh Veis Dam Watershed of Kurdestan Using the IRAT and LNRF Models

Abstract

Landslide is one of the most important agents of soil erosion and occurrence of natural disasters that causes annualy damage in Iran. Morphotectonic indices and landslide hazard zonation models have been increasingly used in the study of slope instability. The purpose of this study was to assess the zoning of landslide hazard at the Chergh Veis Dam Watershed of Kurdestan using the IRAT (LNRF) model and comparative comparisons of them using the cross-sectional table technique and landslide hazard zonation assessment indicators. The results of the IRAT evaluation indicate that 77.77% of the landslides are in the tectonic category; however, using the LNRF model, 64.05% occur in areas with a very high potential that is consistent with the sub-basins with the highest number and large slip density. Moreover, more than 91.64% of the total area of landslides occur in high risk areas and within less than 1000 meters of each other. An analysis of the cross-sectional tables indicate that both zoning models occur in the middle class risk assessment with an acceptable compliance, but on the high risk side duo to the faults' alignment with landslides, the IRAT model is more accurate. The total quality indicators as the LNRF model, 2.16 % indicates that the model performance is better for zoning the landslide risk in the catchment area of the Kesht-e-Wis Dam. It is suggested that any land use change and planning to exploit the landform of the dam watershed be in accordance with the land risk mapping guidelines.

Keywords

• cheraghveis
• irat
• landslide
• lnrf
• morphotectonics