基于GIS的白龙江引水工程水源区地质灾害易发性评价

Geological hazard susceptibility assessment based on GIS in water source area of Bailongjiang river water diversion project

以甘肃省白龙江引水工程水源区为实例,研究新建水库影响范围内的地质灾害发育状况,为水库安全建设与运营管理提供支撑。在遥感解译和野外勘察的基础上,选取高程、坡度、坡向、距断层距离、岩层倾向与坡向的关系和距水系距离6个地质灾害易发性评价因子,分析各因子与地质灾害的内在关系,基于GIS空间分析技术和层次分析法进行地质灾害易发性评价。结果表明:中高易发区主要集中分布在河流两侧,地质灾害点数量占95.65%,评价结果与历史地质灾害分布情况基本吻合,较好地反映了研究区地质灾害发育特征。

The water resources in Gansu province are short and unevenly distributed in time and space, which does not match the economic and social development, population, and cultivated land distribution. The construction of water conservancy project is the key to solving this problem.Taking the water source area of the Bailong River diversion project in Gansu Province as the research area, the development of geological hazards within the influence area of the new reservoir was studied, which could provide support for the safe construction and operation of the reservoir. Based on remote sensing interpretation and field survey, 6 evaluation factors of geological hazard susceptibility were selected, which include elevation, slope, aspect,distance from the fault, the relationship between rock dip and aspect, and distance from the water system.Based on geographical information system(GIS) spatial analysis technology and analytic hierarchy process, the relationship between evaluation factors and geological disasters was analyzed, and the susceptibility of geological disasters was carried out.The historical geological hazards are mainly distributed in the area below 2 300 m elevation, 15° and 30° in slope, within 200 m from the river, and in the south and southeast of the study area. The medium and high-prone areas in the study area accounted for 45.85% of the total area, and geological hazard points accounted for 95.65% of the total geological hazard points.The susceptibility evaluation result is consistent with the distribution of historical geological hazards in the research, which could provide prerequisites for disaster prevention and mitigation work in the reservoir area, and provide technical support for the safe construction and operation of reservoirs.