基于GIS的区域性滑坡空间特征分析

 以日本岩手县早池峰山区域为研究对象,选择坡度、坡向、海拔、坡面倾斜类型、降雨、植被、土壤、地质8个因素,以GIS为工具,结合数量化理论与方法,分析和解明区域性滑坡及其影响因子的空间关系。通过航片解释得到了研究区滑坡分布图;从TM影像计算了研究区植被指数;从数字地图解析出数字高程模型(DEM),进而计算了研究区坡度、坡向、海拔以及坡面倾斜类型;从现有的研究成果提取研究区降雨特征,结合DEM得到了研究区降雨量空间分布图;从现有土地分类基本调查图上提取了土壤类型以及地质类型。通过图形迭加和数量化分析,得出了研究区域滑坡与影响因子的关系。结果表明,所选择的8个因子对滑坡均有较为明显的影响,其影响顺序依次为:海拔高度、植被状况、地质类型、降雨量、土壤类型、坡向、坡度、坡面倾斜类型。

Regional Landslide Analysis Based on GIS Techniques

In the study, eight causal factors of slope, exposure, slope type, elevation, rainfall, vegetation, soil and geology have been considered and analyzed by combining GIS techniques and quantification approach for the research area, Hayachine mountain ranges, Iwate Prefecture, Japan. Landslide information have been gotten from interpreting aerial photograph , vegetation information have been derived from Landsat Thematic Mapper data, data of slope, exposure, slope type and elevation have been determined from Digital Elevation Model (DEM) generated from digital map (1/25000), rainfall data was from previous researches, soil type and geology have been gotten from current investigation map. Based on these and assisted with GIS software, the study focused on: 1) extracting or computing the causal factors which impact on regional landslide using GIS techniques; 2) clarifying the relationship between landslide and its causal factors. The results showed that these eight causal factors have a close relationship with landslide, the sequence (from strong to weak) of these causal factors impacting regional landslide are elevation, vegetation, geology, soil type, rainfall, exposure, gradient and slope type.