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基于GIS的高山峡谷区滑坡灾害危险性评价——以泸水市为例
1,2, 1, 1, 1, 1

(1.yunnandaxue diqiukexuexueyuan, kunming 650500; 2.yunnanshenggaoxiaoguochangaofenweixingyaogandizhigongchengyanjiuzhongxin, kunming 650500)

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GIS-Based Risk Assessment of Landslide Disaster in High Mountain Valley
-Taking Lushui City as an Example

(1.college of earth sciences, yunnan university, kunming 650500, china; 2.yunnan institute of geography, kunming 650500, china)

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备注

为了加深对泸水市滑坡灾害的认识和泸水市防灾减灾的实际需要,以泸水市235个滑坡灾害点数据为基础,分析滑坡的发育特征和形成机理,结合相关性分析,选取坡度、高程、道路、水系、地层岩性、断层、土地利用类型以及降雨量共8个因子构建危险性评价指标体系。基于GIS技术,分析各评价指标与滑坡灾害点相对密度的关系,并对各指标进行分级,然后采用层次分析法和信息量模型,对研究区的滑坡灾害危险性进行了评价和区划。结果表明:(1)研究区滑坡易发生在坡度30°~50°、高程小于1 900 m,区内软弱岩体或软硬相间的岩层较易引起滑坡灾害的发生,且距道路、断裂带和河流越近,发生滑坡灾害的可能性越大,降雨量对滑坡的发生也有影响,滑坡发生的概率随降雨量的增加而增加,建设用地和耕地极易发生滑坡灾害。(2)研究区滑坡灾害极高和高危险区主要分布在人类活动较为强烈的河流两岸和道路沿线。(3)极高、高、中、低危险区的面积分别为448.75 km2,848.51 km2,1 011.61 km2,779.54 km2,极高和高危险区仅占研究区总面积的42%,却包含86.81%的滑坡灾害点,滑坡密度高达0.157 3个/km2,说明该区域危险性较高。
In order to deepen the understanding of landslide disasters in Lushui City and meet the actual needs of disaster prevention and mitigation in Lushui City, the development characteristics and formation mechanism of the landslide in Lushui City were analyzed based on the data of 235 landslide disaster points. Combined with correlation analysis, 8 factors including slope, elevation, road, water system, stratigraphic lithology, fault, land use type and rainfall were selected to build a risk assessment index system. Based on GIS technology, the relationship between each index and the relative density of landslide disaster points was analyzed, and each index was graded. The analytic hierarchy process and information model were used in evaluation and zoning of the landslide hazard risk in the study area. The results show that:(1)landslides in the study area are prone to occur between slopes of 30°~50° and elevations less than 1 900 m; soft rocks or soft-hard rock layers in the area are more likely to cause landslide hazards; the closer to the road, fault zone and river, the greater the possibility of landslide disaster; the rainfall also has the impact on the occurrence of landslides; the probability of landslides increases with the increase of rainfall; construction land and cultivated land are prone to landslide disasters;(2)the extremely high and high risk areas of landslide hazards in the study area mainly distributed on both banks of rivers and roads where human activities are strong;(3)the areas of extremely high, high, medium and low risk areas are 448.75 km2, 848.51 km2, 1 011.61 km2 and 779.54 km2, respectively; the extremely high and high risk areas only account for 42% of the total area of the study area, but contain 86.81% of the landslide disaster points, and the landslide density is as high as 0.157 3 km2, indicating that the landslide risk in this area is high.
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