基于数值模拟的白沙河流域干沟泥石流风险评价

发布时间：2018-03-25 16:07

本文选题：泥石流　切入点：数值模拟　出处：《西南科技大学》2015年硕士论文

【摘要】：白沙河流域位于“5.12”汶川特大地震灾害重灾区,2009年7月17日白沙河流域遭遇强降雨,干沟暴发了一次大规模泥石流。在借鉴国内外风险评价理论与技术方法的基础上,调查了白沙河流域的自然环境条件与社会经济条件以及干沟泥石流分区特征,利用FLO-2D软件,结合降雨量数据、研究区数字高程模型以及泥石流的各种流变参数,模拟“7.17”干沟泥石流发生时的运动状态,获取流体流深、流速以及堆积情况。模拟结果根据泥石流的勘察报告进行模拟参数的调整,使模拟的结果和泥石流发生的实际情况大致吻合,以此确定干沟泥石流数值模拟流体参数。本文还基于乔建平等提出的以雨强为标准的超越概率统计模型,推算得出重现期为30年、50年、100年和200年的降雨量阈值,得知“7.17”干沟泥石流为重现周期200年的情况。结合重现期为30年、50年和100年的降雨量阈值和“7.17”干沟泥石流反演得到数值模拟流体参数,分成无工程情况和有工程情况,预测干沟泥石流在重现周期为30年、50年和100年降雨情况下泥石流可能影响的范围和堆积情况。本文选取由数值模拟得到的泥石流流深和流速作为危险性评价因子,对不同降雨频率下的干沟泥石流进行危险性评价,绘制出危险性分区图。在数值模拟得到的危险范围内,结合遥感解译数据和实地调查数据,运用刘希林单沟易损性评价模型,得到在不同降雨频率下,有拦挡坝工程情况和无拦挡坝工程情况下干沟泥石流易损性评价结果,并绘制出易损性分区图。在危险性和易损性评价的基础上,进行干沟泥石流风险性评价,计算了不同降雨频率下的干沟泥石流风险度,绘制出风险分区图,为当地地质灾害的防灾减灾工作提供更为科学合理的依据,为地方经济、社会和环境的可持续发展提供决策支持。
[Abstract]:The Baisha River Basin is located in the "5.12" Wenchuan earthquake disaster area. On July 17, 2009, the Baisha River Basin suffered heavy rainfall and a large debris flow broke out in the dry gully. The natural environment, social and economic conditions of Baisha River Basin and the characteristics of debris flow zoning in dry gullies were investigated. The digital elevation model and various rheological parameters of debris flow in the area were studied by using FLO-2D software and rainfall data. The movement state of debris flow occurred in the "7.17" dry ditch was simulated, and the fluid flow depth, velocity and accumulation were obtained. The simulation results were adjusted according to the investigation report of the debris flow. The simulation results are roughly consistent with the actual conditions of debris flow occurrence, and the fluid parameters of numerical simulation of dry gully debris flow are determined. This paper also based on the transcendental probability statistical model based on rainfall intensity proposed by Qiao Jianping et al. We calculated the threshold of rainfall for 30, 50, 100, and 200 years for a recurrence period of 30, 50, 100, and 200 years. It is known that "7.17" dry gully debris flow is 200 years of recurrence cycle. Combined with the threshold of rainfall of 30 years, 50 years and 100 years and the inversion of "7.17" dry ditch debris flow, the numerical simulation fluid parameters are obtained, which can be divided into engineering and engineering conditions. The range and accumulation of debris flow in dry gully are predicted when the recurrence period is 30 years, 50 years and 100 years. In this paper, the debris flow depth and velocity obtained by numerical simulation are selected as risk assessment factors. The hazard assessment of dry gully debris flow with different rainfall frequency was carried out, and the hazard zoning map was drawn. In the danger range obtained by numerical simulation, combined with remote sensing interpretation data and field investigation data, Liu Xilin single gully vulnerability evaluation model was used. The results of vulnerability assessment of debris flow in dry gully under different rainfall frequency, with and without blocking dam are obtained, and the zoning map of vulnerability is drawn. Based on the evaluation of risk and vulnerability, The risk degree of dry gully debris flow under different rainfall frequency is calculated, and the risk zoning map is drawn, which provides a more scientific and reasonable basis for local geological disaster prevention and mitigation, and provides a more scientific basis for local economy. Social and environmental sustainable development provides decision-making support.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.23

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