基于模糊概率的区域泥石流危险性评价

Fuzzy Probability-Based Evaluation for Regional Debris Flow Hazard

在最新泥石流危险度区划研究的基础上,将模糊概率模型应用于区域泥石流灾害的危险评价中。在此模型中,评价指标因子包括主要因子泥石流分布密度,次要因子岩石风化程度系数、断裂带密度、≥25°坡地面积百分比、洪灾发生频率、月降雨量变差系数、年平均≥25mm大雨日数以及≥25°坡耕地面积百分比;同时将泥石流危险划分为极低危险、低度危险、中度危险、高度危险和极高危险5个等级。模糊概率模型不仅继承了经典模糊综合评判法的思想和优点,同时也克服了其在实际应用中评价指标因子权重取值的局限性,因而具有明显的合理性。对四川省凉山州区域泥石流灾害的危险评价分析,表明本方法能较真实地反映区域泥石流灾害的危险等级,可为减灾防灾决策提供科学依据。

Based on the newly research on regionalization of debris flow hazard degree,the fuzzy probability-based model for classification of regional debris flow hazard is investigated in this paper.Assessing factors include debris flow spatial density,degree of weathering of rock,active fault density,percentage of slope greater than 25 degrees of the total,frequency of flooding hazards,average covariance of monthly precipitation,average days with rainfall greater than and equal to 25mm by ten years,and percentage of cultivated slope greater than 25 degrees of the total in the model.And the regional hazard of debris flow is divided into five grades,i.e.,the negligible hazard,low hazard,moderate hazard,high hazard and very high hazard.In this way,the fuzzy probability model not only holds the merit of classical fuzzy comprehensive evaluation method,but also overcomes its limitations in practice.Through the analysis of regional debris flow hazard of Liangshan of Sichuan province in southwestern China,the results show that,this method can reflect truly the hazard degree of the regional debris flow.It provides scientific basis for prevention and reduction of the regional debris flow hazard.