GIS based landslide hazard mapping with application of analytical hierarchy process for Da Lat City

Abstract

Landslide hazard mapping for Da Lat City has been generated by Analytical Hierarchy Process AHP and GIS. Thirteen causual factors were selected, including slope, geomorphology, river catchment density, lithology-weathering zone, soil, geodynamic structure, dynamic impact zone of main faults, peak ground acceleration, hydrogeology, annual average rainfall, land use, construction density, and transport system. Landslide hazard zoning was verified by comparing it with the current 214 landslide locations detected from the actual investigation and survey. Results showed that 94.8% of landslide locations occurred in moderate to very high hazard areas. Areas with deficient, low, medium, high, to very high landslide hazard accounted respectively for 21.76%; 36.14%; 21.15%; 15.91%, and 5.04% of the study area. Slope > 25o, annual average rainfall from 1800-1900mm, construction density > 80%, and traffic system with a buffer of 20m were considered as the main causual factors to landslide occurrence in Da Lat City. Research results are a scientific and practical basis for local planners and managers to use suitably the city territory, considering the landslide condition in the socio-economic development master plan.

Keywords

• phương pháp phân tích thứ bậc ahp
• trượt lở đất
• thành phố đà lạt