Spatial distribution and susceptibility analysis of avalanche, landslide and debris flow in Beijing mountain region

ObjectiveThis paper aims to assess the sensitivity of factors affecting the occurrence of mountain hazards in Beijing, and explore the hazard distribution characteristics and laws in this area.

MethodUsing ArcGis 10.2 as the processing platform, the spatial distribution of avalanche, landslide and debris flow in Beijing mountain region were analyzed. Based on five evaluation-factors including respect to faults, lithology, slope degree, slope aspect and the average rainfall by ARCGIS spatial analysis and sensitivity coefficient.

ResultThe experiments showed that the concerned three kinds of hazards were mainly located in the range of 0-6km to the faults, where 86% hazards were located. The density of hazard site within the area of 2km to fault reached 0.83 points per square kilometers, and the sensitivity coefficient was 1.95; the avalanche, landslide and the debris flow mainly located in the granite strata, and the sensitivity coefficient "S_ci" was 7.05, 3.46, 5.89, respectively. The maximum S_ci of avalanche, landslide and debris flow was 1.14, 1.68, 0.90, respectively in the area where the annual precipitation ranged between 710-730mm, 710-730mm, 630-650mm. Three hazards were prone to occur in the slope terrain with average slope gradient of 5°-15°, the corresponding sensitivity coefficient "S_ci"was 0.75, 0.53, 0.93, respectively. The avalanche and landslide were located in southwest aspect terrain, and the "S_ci" was 0.37 and 0.64; the debris flow mainly occurred in the river basin while the slope of the disaster was not fixed.

ConclusionIn conclusion, assigning susceptibility of different impact factors for hazards, using spatial overlay analysis and grid accumulation in ARCGIS, we get the susceptibility distribution map of three kinds of disasters and a further understanding of the occurrence of mountain hazards in Beijing mountain area.