Sensitivity analysis of disaster-pregnant environmental factors for slope geological hazards in Kaiyang County, Guizhou Province

The geological conditions are complex in Kaiyang County, and geological disasters occur frequently. On the basis of field geological hazard investigation, 8 factors including elevation, slope, slope direction, engineering petrofabric, slope structure, fault, drainage and NDVI value are selected as the disaster-pregnant factors of slope geohazards. Based on the GIS platform, and by using the certainty factor model(CF) and the sensitivity-exponential(E), susceptibility of these 8 factors are researched. The results show that the areas with elevation from 515 to 993 m, the slope degree from 20° to 50°, the aspect of the west, the northwest and the southeast, soft rock group, the consequent slope area, the distance from fault and rivers within 1 000 m, 800 m respectively and the NDVI value in -0.098 to 0.181 are sensitive areas of geohazards. Compared with the slope structure and the NDVI value which showed lower sensitivity, the others, slope, lithology, aspect, the distance from fault and rivers and elevation are the main control factors of the area. The further discussion results show that the sensitivity of the NDVI value is likely to be restricted by the elevation range of 1 288-1 664 m and the aspect of the north, and the sensitivity of the slope structure is limited by the aspect of east and west. The research results can provide reference for the prevention and reduction of geohazards in Kaiyang County.