粤北山区某泥石流风险的精细化评价研究

Research on refined risk assessment of the debris flow in the mountainous area of northern Guangdong Province

单体泥石流沟风险的精细化评价对于泥石流的风险防控意义重大。本文以粤北山区某泥石流为研究对象,基于泥石流动力学理论建立了泥石流强度和危险性的精细化评价模型,并结合现场调查,采用社会易损性和物质易损性两个指标建立人口和建筑易损性评价体系,最后根据泥石流危险性及易损性评价结果,采用风险计算公式对二者进行耦合,完成不同重现期泥石流风险定量评价结果。结果表明:通过对泥石流的反演分析,模型能较好揭示泥石流的动力学过程;不同重现期下的泥石流灾害均会对沟口村庄造成破坏,且随着降雨频率的增加危险范围逐渐增加,百年一遇泥石流风险区面积达27754 m^(2),其中位于极高风险区建筑物9栋,位于高风险区建筑物10栋,位于中风险区建筑物5栋,位于低风险区建筑物2栋。研究成果可为泥石流防灾减灾提供理论依据及技术支持。

The refined risk assessment of a single debris flow gully is significant for risk prevention and control of the debris flow.In this paper,the debris flow in the mountainous area of northern Guangdong Province was chosen as the research subject.Based on the theory of debris flow dynamics,refined assessment models of debris flow intensity and hazard were established,and combined with the field survey,the two indicators of social vulnerability and physical vulnerability are used to establish the evaluation system of population and building vulnerability.Finally,according to the assessment results of debris flow risk and vulnerability,and the quantitative assessment results of debris flow risk in different return periods are completed.The results show that the inversion analysis of debris flow shows that the dynamic model can better reveal the dynamic process of debris flow;debris flow disasters under different return periods will cause damage to villages at the gully entrance,and with the increase of rainfall frequency,the dangerous area has gradually increased.The area of the once-in-a-century debris flow risk area is 27,754 m^(2),including 9 buildings in the extremely high risk area,10 buildings in the high risk area,5 buildings in the medium risk area,and 2 buildings in the low risk area.The research results can provide theoretical basis and technical support for debris flow disaster prevention and mitigation.