Geohazard susceptibility evaluation of Qianyang County, Baoji area, Shaanxi

Based on detailed investigation of geohazards in Qianyang County, the authors made evaluation zoning of geohazard susceptibility degrees in Qianyang County by using the combined qualitative analysis and quantitative evaluation. First, they qualitatively analyzed the distribution characteristics and main influence factors of geohazards, Then the geometric shape of the slope, engineering geological rack fabrics, thickness of loess overburden, geological structure and hydrogeological conditions and 28 indicators were selected as the evaluation factors, and the susceptibility evaluation zoning of geohazards in Qianyang County was performed by using the geographical information system technique and the information amount model. High-class susceptibility districts account for 4.89% of the area of the whole region, mainly distributed in the slope on the side of the loess “Yuan” on both sides of the first-order distributary in the loess “Yuan”” area on the north bank of the Qianhe River; moderate-class susceptibility districts account for 24.18% of the region, mainly located on both sides of the first-order distributary in the loess “Yuan” area on the north bank of the Qianhe River and in the contact area between loess and bedrocks (Cretaceous-Jurassic sandy mudstone) eroded by the second- and third-order distributaries in the mountainous area in the north, as well as the high and steep area covered locally by the mountainous area in the south; low-class susceptibility districts account for 41.29% of the region, mainly lying in erosion areas of the second- and third-order river channels in the mountainous area in the north of Qianyang and in the loess “Yuan” area on the north bank of the Qianhe River and the bedrock mountainous area south of the Qianhe River.