基于自然邻点插值计算的溃堤洪水二维模型.docVIP

基于自然邻点插值计算的溃堤洪水二维模型 　　摘要：为了模拟溃堤洪水的演进过程，建立计算区域的二维水动力模型，采用基于非结构网格的Roe格式离散求解。针对保护区内存在线状地物等实际特点，将道路、灌渠渠堤等建筑物线性处理，概化为宽顶堰的形式计算，赋予实际高程，将其作为特殊边界与非结构网格耦联；采用自然邻点插值计算方法，将保护区与排水沟分区插值，还原区域内排水沟地形，通过以上方法，获得了具有真实地形的模型。将模型应用于青铜峡河西灌区四排口险工溃堤洪水模拟，有效模拟了道路、渠堤等特殊边界阻水和桥涵过水效果，以及排水沟内排水和入河口洪水倒灌过程，较为真实地反映了洪水在计算区域内的演进过程和淹没范围，具有较好的应用价值。 　　关键词：二维模型；特殊边界；非结构网格；耦联；自然邻点插值计算；分区插值；青铜峡河西灌区 　　中图分类号：TV131.2 文献标志码：A 文章编号：1672-1683（2016）04-0014-07 　　Abstract：In order to simulate the flood wave propagation through the breaches，a two-dimensional hydrodynamic model was developed.Roe method of unstructured mesh was used to solve the 2D model.Based on the actual characteristics such as linear features in the flood protected zone，ways and irrigation ditches were generalized to broad crested weir for calculation and endowed real height，considering it as special border and coupled unstructured mesh.Using the Natural Neighbor Interpolation，separated interpolation was conducted between protected zone and aqueduct，and terrain of aqueduct in the area was recovered，and model with real terrain was obtained through the above methods.The model was applied to the case of Qingtongxia West Irrigation of Yellow River on Sipaikou，effectively simulated water blocking of special border such as ways and irrigation ditches and water flow of bridge culverts，and the effect of drain in the aqueduct and intrusion in the estuary，and truly simulated the flood wave propagation and inundation area of flood in calculation area，thus the paper has bright application value. 　　Key words：two-dimensional model；special border；unstructured mesh；coupled；natural neighbor interpolation；separated interpolation；Qingtongxia West Irrigation of Yellow River 　　近年来，由于河道中上游植被减少，导致流域涵养水源、调节径流、削减洪峰能力降低，加之水土流失加剧，河床淤高，泄洪能力降低，洪涝灾害的发生日趋频繁。在洪水冲刷的情况下，堤防一旦溃决，将造成房屋倒塌、农田绝收的严重后果。因此，对溃堤洪水在保护区域内的演进过程进行数值模拟，可以有效开展溃堤洪水的风险分析，为防汛救灾提供决策依据。 　　采用二维水动力学模型模拟溃堤洪水在二维平面上的演进情况，可以获得良好的模拟效果，近年来在国内外有着广泛的应用。求解二维模型最初采用有限差分法，有限元法和有限体积法等也被应用到二维水流数学模型的求解中。姜晓明等[1]采用基于黎曼近似解的水动力学模型对松花