Spatial hazard analysis and prediction on rainfall-induced landslide using GIS

Abstract

The application of landslide hazard model coupled with GIS provides an effective means to spatial hazard analysis and prediction on rainfall-induced landslides. A modified SINMAP model is established based upon the systematic investigation on previous GIS-based landslide analysis models. By integrating the landslide deterministic model with the hydrological distribution model based on DEM, this model deeply studied the effect of underground water distribution due to rainfall on the slope stability and landslide occurrence, including the effect of dynamic water pressure resulting from the down slope seepage process as well as that of static water pressure. Its applicability has been testified on the Xiaojiang watershed, the rainfall-induced landslides widespread area in Southeast China. Detailed discussion was carried out on the spatial distribution characteristics of landslide hazard and its extending trend, as well as the quantitative relationship between landslide hazard with precipitation, slope angle and specific catchment area in the Xiaojiang watershed. And the precipitation threshold for landslide occurrence was estimated. These analytical results are proved useful for geohazard control and engineering decision-making in the Xiaojiang watershed.