基于流域单元的泥石流危险度评价方法研究以四川省大渡河流域为例

目前广泛应用的区域泥石流危险度评价方法是由刘希林提出的多因子综合评价法，该方法主要以行政区域为评价单元，没有体现泥石流发生特定的地貌条件，且部分指标获取难度大。本文以流域为评价单元建立泥石流危险度评价体系，根据形成泥石流所需的地形条件、物源条件和水动力条件选择与物源、沟道和降雨相关的因子作为评价指标，为各因子和指标赋权重，利用GIS进行叠加和分析。以大渡河为例，在分析大渡河流域泥石流发育特征的基础上，选取相关因子和指标，对大渡河流域泥石流危险度进行评价，评价结果与实际情况吻合较好，可为政府部门制定减灾防灾决策提供参考。

RESEARCH ON DEBRIS FLOW HAZARD ASSESSMENT METHOD BASED ON WATERSHED UNIT-TAKING THE DADU RIVER BASIN IN SICUAN PROVINCE AS AN EXAMPLE

At present, the widely used method of regional debris flow hazard assessment was proposed by Liu Xi-lin. Because the method is based on administrative region as assessment unit, it does not reflect the geomorphic conditions of debris flow, and it is difficult to get some assessment indexes. Based on watershed unit, the article establishes the assessment system of debris flow. According to the topographic conditions, source conditions and hydrodynamic conditions required for the formation of debris flow, the factors related to debris flow source, channel and rainfall are selected and assigned as the assessment index, which are analyzed and evaluated using GIS technique. Taking the Dadu river basin as an example, according to the development characteristics of debris flow, relevant factors and indexes are selected to evaluate debris flow hazard; the evaluation results are in accordance with the actual situation, which is helpful for planning to reduce the damage by government.