陕西省地质灾害与影响因素相关性研究

Based on the detailed investigation results of geological disasters in various cities and counties in Shaanxi Province, a database of the spatial distribution of geological disasters and five influencing factors such as topography, geomorphology, and stratum lithology was established using GIS technology. The elements of the database were converted into raster data of 50 × 50 m. After reclassification, the number of raster cells where geological disasters occurred in each factor was counted, and the correlation coefficient with the distribution of geological disasters was calculated. The results show that: geological disasters in Shaanxi Province are most developed in the geomorphic unit of the Qinling - Dabashan Mountains in southern Shaanxi; among various stratum lithologies, the Ordovician has the greatest impact on geological disasters; areas with an elevation of 400 - 800 m, a slope of 20° - 30°, a sunny slope with an absolute value of slope curvature greater than 1, and an annual average rainfall greater than 700 mm are all prone to geological disasters; along fault zones, rivers, and traffic lines, geological disasters show a "banded" distribution, and the correlation coefficient decreases in the direction away from the fault zone (river, traffic line). The research results provide a basis for the prevention and treatment of geological disasters in Shaanxi Province.

基于陕西省各市县地质灾害详细调查成果资料,利用GIS技术建立了地质灾害空间分布和地形地貌、地层岩性等5个影响因素的数据库,将数据库要素转换为50 × 50 m的栅格数据,重分类后统计各因素中发生地质灾害的栅格数目,计算其与地质灾害分布的相关性系数。结果显示:陕西省地质灾害在陕南秦巴山区地貌单元中最为发育;各地层岩性中,奥陶系对地质灾害的影响最大;高程为400 ~ 800 m,坡度为20° ~ 30°,以及坡型曲率绝对值大于1的阳坡和年平均降雨量大于700 mm区域均为地质灾害易发区域;沿着断裂带、河流和交通线路,地质灾害呈现出“带状”分布,相关性系数沿着远离断裂带(河流、交通线路)的方向减小。研究结果对陕西省地质灾害的预防和治理提供依据。