基于灰色关联度的舟曲小流域泥石流灾害风险评价

近年来,随着我国社会经济的迅速发展,城镇和农村基础设施建设亦如火如荼的展开,山区开发建设已成为常态。特殊的地形地貌、气候、地质条件及人类活动等诸多因素为地质灾害的发生提供了孕灾条件,而泥石流是最主要的灾害类型之一,该地质灾害对人民的生命和财产安全构成了巨大的威胁。为了做好防灾减灾工作,构建较为精确的泥石流风险评价模型极为迫切。本文基于舟曲县泥石流形成条件及特征并参照问卷调查结果,选取10个指标作为泥石流风险评价因子,利用灰色关联度方法构建了泥石流危险度评价模型,计算了各指标的权重并获得了各沟泥石流危险度;运用受威胁财产和人口构建评价模型,进而得到了各沟易损度值;通过危险度与易损度乘积建立风险度模型,得出各泥石流风险度结果,其中极高风险区占比27.27%、高风险区占比36.36%、中风险区占比18.18%、极低风险区占比18.18%。将计算结果和实际调查数据进行对比,发现两者结果基本吻合,表明该方法可靠实用,能够准确反映山区泥石流灾害的发生风险,为该类地质灾害的防灾减灾工作提供理论依据。

Risk Assessment of Zhouqu Debris Flow Disaster Based on Grey Relational Degree

In recent years, with the rapid development of social economy in our country, urban and rural infrastructure construction expands on a full swing, and development in mountainous regions has become normal. Many factors, such as special topography, climate, geological conditions and human activities, provide the conditions for the occurrence of geological disasters, and debris flow is one of the most important types of disasters, which poses a great threat to people"s life and property safety.In order to prepare for disaster prevention and mitigation, it is urgent to build a more accurate risk assessment model of debris flow. Based on the formation conditions and characteristics of debris flow in Zhouqu County and referring to the results of questionnaire survey, 10 indicators are selected as the risk evaluation factors, and the grey relational degree method is used to build the risk evaluation model. The weight of each indicator is calculated and the risk degree of debris flow in each gully is obtained by the grey relational degree method. The evaluation model is built by using threatened property and population, and then the vulnerability value of each ditch is obtained. The risk degree model was established by the product of risk degree and vulnerability degree, and the risk degree results of each debris flow are obtained. The extremely high risk area, high risk area, medium risk area and very low risk area accounts for 27.27%, 36.36%, 18.18%, and 18.18%, respectively. By comparing the calculated results with the actual survey data, it is found that the two results are basically consistent, which indicates that the method is reliable and practical. The method can accurately reflects the risk of debris flow disasters in mountainous areas, and provide a theoretical basis for the prevention and mitigation of such geological disasters.