溃堤山洪淹没风险评估水动力耦合模型及应用

Hydrodynamic coupling model and its application for risk assessment of dike burst mountain flooding

建立山洪沟道溃堤洪水演进一、二维水动力耦合数值模拟模型,分析评估溃堤山洪淹没风险。针对阻水道路和灌渠渠堤等特殊边界,将其概化处理为宽顶堰并利用非结构化网格加密剖分技术耦联特殊边界,同时采用干湿水深理论提高模型计算效率,使溃堤山洪耦合模型能够准确反映计算区真实地形以及水流的动态演进过程。将模型应用于宁夏大武口沟城区段100年一遇溃堤山洪演进计算,模拟了沟道与溃口分流洪水运动以及两者动态交互传递过程,并分析了洪水淹没风险分布特征及影响情况,研究成果可为山洪沟道溃堤洪水风险评价及防洪规划等提供技术支持。

The one-and two-dimensional hydrodynamic coupling numerical simulation models of flood control in dike burst caused mountain flood ditch were established,and the risk of flood inundation was analyzed and evaluated.The special boundaries such as road and irrigation canal were generalized as a wide crest weir and treated linearly.The unstructured grid encryption and dissection technology were used to couple the special boundary,so that the breaking embankment mountain flood coupling model could accurately reflect the real terrain of the calculation area.At the same time,the wet and dry depth theory was used to optimize the model calculation efficiency.The model was applied to calculate and simulate the break dike mountain flood routing once in 100 years occurred in the city section of Dawukou ditch in Ningxia Province.The evolution of ditch flood in the submerged area was simulated,and the distribution characteristics and impacts of flood inundation was analyzed.The research results could provide technical support for flash flood risk assessment and flood control planning of mountain ditches.