清远市滨江河口段堤线外移对北江河道行洪的影响

Impact of Levee Realignment on Flood Control of Beijiang River at Binjiang Estuary in Qingyuan City

采用一维、二维水动力模型相结合的方法研究清远市滨江河口段局部堤线外移工程对河道行洪的影响,一维模型模拟较大范围河网的水动力特征,用于计算工程建设前后河道水位变化,并为二维模型提供边界条件,经验证模型精度较高;二维模型基于三角形网格的有限体积法,能细致模拟滨江河口流速和流向。结果表明,工程建设后滨江和北江在堤线外移工程附近河段水位、流速和流态均有所变化,水位壅高值在0.011m以内,流速最大变化值为0.409m/s,变化幅度均较小,且范围局限于工程附近,基本不会对河道行洪构成威胁。

In this paper, the impact of levee realignment on flood control of Beijiang River is studied by combining 1- D models with 2-D hydrodynamics models. The 1-D model simulates flow characteristic in a larger extent of river and is verified to get satisfactory precision in different hydrological state, which can be used to compute water level along the river and provide boundary conditions to 2-D models in this example. While the 2-D model based triangle mesh and FVM deeply simulates flow velocity and flow direction of Binjiang estuary. The simulation results show that theproject has little impact on water level and flow velocity in a limited extent of river network. The water level increments are less than 0. 011m, and the maximum change of flow velocity is 0. 409m/s. Therefore, we can get conclude that the project will not pose threat to flood discharge capacity of Beijiang River.