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泥石流敏感性分析对灾害分析评价预测具有重要作用。文章以长江上游为研究区,选择坡度、相对高差、地层岩性、年降雨量、地震烈度等5方面因素为评价因子,探讨运用GIS技术管理分析泥石流灾害信息和区域泥石流敏感性分析的方法。量化评价因子的作用分值大小,有效表达泥石流敏感性指数(DFSI),进而,结合空间分析与条件概率模型,实现了区域泥石流敏感性分析并制作了泥石流敏感性专题图。长江上游地区泥石流敏感性区域具有一定的规律性,高度敏感区主要分布在第一级阶梯与第二级阶梯的过渡地带,比较集中的区域有雅砻江中下游、安宁河、小江、普渡河、大渡河中下游、理塘河、白龙江、岷江上游、涪江上游等干支流的5～10 km范围内;中度敏感区主要分布在高度敏感区的外围约10～30 km范围内。利用历史泥石流资料验证,表明已经发生的泥石流主要分布在泥石流敏感性指数较高地区,说明敏感性分析的结果基本反映出研究区泥石流敏感性特性。
Debris flow sensitivity analysis plays an important role in disaster analysis. Taking the upper reaches of the Yangtze River as the study area, five factors such as slope, relative height difference, stratigraphic lithology, annual rainfall and seismic intensity are selected as evaluation factors, and the methods to analyze and analyze debris flow hazard information and regional debris flow sensitivity using GIS are discussed . Quantify the role of evaluation factor scores, effectively expressing the debris flow susceptibility index (DFSI), and then, combined with spatial analysis and conditional probability model, to achieve the regional debris flow sensitivity analysis and production of the debris flow sensitivity map. The sensitive area of debris flow in the upper reaches of the Yangtze River has certain regularity. The highly sensitive areas are mainly located in the transitional zone of the first and second steps. The more concentrated areas are the middle and lower reaches of Yalong River, Anning River, Xiaojiang River and Purdue River , Middle and lower reaches of Dadu River, Litang River, Bailong River, upper reaches of Minjiang River and upper reaches of Fujiang River. The moderately sensitive areas are mainly distributed in the range of 10 ~ 30 km outside the highly sensitive area. The use of historical debris flow data validation, shows that the debris flow has occurred mainly in the debris flow sensitivity index of high areas, indicating that the sensitivity analysis results basically reflect the study area of debris flow sensitivity.