重庆铜梁地质灾害敏感性评价及可视化分析

Evaluation of Geological Hazard Sensitivity in Tongliang District, Chongqing Using GIS

以GIS为技术手段,采用信息量法,选取地形坡度、斜坡坡向、地层岩组、与水系的距离、与活动构造的距离、降雨量等6个评价因子作为评价指标,对重庆市铜梁区地质灾害的敏感性进行评价及可视化分析。研究结果表明:(1)研究区地质灾害多发生于坡度为10°~30°、坡向朝东南和南以及地层岩组为侏罗系中统沙溪庙组的区域;地质灾害易发生于距水系小于200 m的区域;月均累计降雨量大于80 mm的区域,地质灾害发生的概率明显高于降雨量小于80 mm的区域;(2)研究区现有地质灾害点主要集中分布于东北部和南部地区,且呈集聚和条带状分布;(3)较高敏感区和敏感区面积占全域面积的49.22%;较高敏感区和敏感区的地质灾害点数占现有地质灾害总数的90.74%。

In this paper, the GIS is as the major visualization evaluation tool for the geological hazard sensitivities in Tongliang District, Chongqing City. Six(6) factors, namely, slope of the topography, bedrock inclinations(incline or anticline), bedrock stratigraphy, distance to the waterway system, distance to the active structural tectonics and precipitations, are considered in the evaluation. The results show that:(1)the geological hazards in the study area are mostly occurred in the area with a topographical slope between 10° and 30°, the bedrock inclination direction towards southeast and south, and the bedrock stratigraphy formation of Middle Jurassic Upper Shaximiao Formation;Geological hazards are prone to occur in areas less than 200m away from the waterway system. The probability of the geological hazards is significantly higher in the area with monthly accumulated precipitation greater than 80mm than in the area with rainfall less than 80mm.(2)The existing geological hazard points are mainly distributed in the northeast and south of the study area, and they are concentrated and banded;(3)The area of high sensitivity and sensitive area accounted for 49.22% of the total area;The number of geological hazards in high sensitivity and sensitive area accounts for 90.74% of the total number of existing geological hazards.