泥石流是我国西部山区常见的地质灾害之一,其强大的致灾能力不仅使人民生命财产蒙受巨大损失,还会对山区生态地质环境造成毁灭性破坏,故准确评价泥石流灾害易发性对防灾减灾工作至关重要。将泥石流灾害易发性分为4级,分别为不易发(Ⅰ)、低易发(Ⅱ)、中易发(Ⅲ)和高易发(Ⅳ)。选取沟谷岸坡坡度(X₁)、沟床纵坡比降(X₂)、植被覆盖率(X₃)、单位面积固体物源储量(X₄)、汇水面积(X₅)、雨季降雨量(X₆)为泥石流灾害易发性定量评价指标,并确定各评价指标分级标准及正态云模型数字特征量,进而构建泥石流灾害易发性评价指标体系与评价指标正态云模型。采用层次分析法与熵权法计算评价指标主、客观权重,基于博弈论思想对主、客观权重进行组合赋权,最终建立基于博弈论组合赋权法的泥石流灾害易发性评价云模型。选取西秦岭地区5条泥石流沟实例验证评价模型有效性,结果表明博弈论组合赋权-正态云模型评价结果与实际情况基本一致。进一步应用该模型对西安大长胜坊与小长胜坊村内的一条黄土沟道进行泥石流灾害易发性评价,结果表明该黄土沟道泥石流灾害易发性等级为Ⅲ级(中易发)。

Debris flow is a common geological disaster in the mountainous area of west China leading to huge loss of people’s property and life and devastating ecology and geological environment. Evaluating the susceptibility of debris flow accurately is of crucial importance to disaster prevention and mitigation. In this paper, a cloud model of evaluating the susceptibility of debris flow is built based on the game theory. The susceptibility of debris flow is classified into four levels: not susceptible (level Ⅰ), lowly susceptible (level Ⅱ), moderately susceptible (level Ⅲ), and highly susceptible (level Ⅳ). Qualitative indices are determined as slope gradient of gullies (index X₁), longitudinal gradient of gully bed (index X₂), vegetation coverage (index X₃), solid material source storage per unit area (index X₄), catchment area (index X₅), and rainfall in wet season (index X₆). The criteria of rating these indices and the characteristic quantities of the corresponding cloud models are proposed. Moreover, the subjective weights and objective weights of the evaluation indices are calculated using hierarchy analytical method and entropy method respectively, and the combinatorial subjective and objective weights are given in the light of the game theory. The effectiveness of the proposed model is verified by five debris flow examples in the west Qinling Mountain area. The evaluation result is consistent with the actual situation in general. The model is further applied to evaluating the susceptibility of debris gully in Xi’an, and the result suggests that the debris flow is moderately susceptible (level Ⅲ).