基于MIKE模型的山洪沟风险分析——以北京怀柔区龙泉沟为例

Risk analysis of mountainous gully based on MIKE model—Taking Longquan Gully in Huairou District of Beijing as an example

山洪灾害具有影响范围广、危害严重的特点,已成为防灾减灾中突出的问题。研究以北京怀柔区龙泉沟为例,基于现场调查、地形测绘等确定控制断面和临界水位,通过构建MIKE11HD-NAM耦合模型,获取水位—流量关系、降雨—流量关系,提出将不同土壤含水状况下1h、3 h、6 h、12 h及24 h的雨量预警指标作为立即转移指标;采用MIKE FLOOD构建MIKE11-21耦合模型,模拟分析沟道不同土壤含水状况、降雨历时、降雨量级下的淹没风险,结果表明龙泉沟防洪能力不足。研究为确定全市其他山洪流域预警指标提供参考,并为山洪灾害预案编制、预报预警及避险转移提供依据。

Flash flood disasters have the characteristics of wide impact and serious harm,and have become a prominent problem in disaster prevention and mitigation.Taking Longquan Gully in Huairou District,Beijing as an example,based on field investigation and topographic mapping,the control section and critical water level were determined.By constructing the MIKE11-NAM coupled model to obtain the water level-flow relationship and rainfall-flow relationship,the rainfall warning indicators for 1 h,3 h,6 h,12 h and 24 h under different soil water content conditions were proposed as immediate transfer indicators.MIKE FLOOD was used to realize the MIKE11-21 coupling model to simulate and analyze the inundation risk of the ditch under different soil water content conditions,rainfall calendar times,and rainfall levels,and the results showed that the flood control capacity of Longquan Gully was insufficient.It provides a reference for determining the early warning indicators of other flash flood basins in the city,as well as the compiling of flash flood disaster plans,forecasts and early warnings and risk avoidance transfer.