基于 MIKE21 FM 的南渡江河口段行洪能力分析

为预测并分析滨江西带状公园建设后对南渡江河口段行洪能力的影响, 基于 MIKE21 FM 水动力模块, 建立了南渡江河口段平面二维水流数值模型。首先结合水文站实测洪水资料, 对河口段河道、滩地糙率参数进行率定与验证。将公园模型概化为局部阻力修正和局部地形修正两种方式, 然后分别模拟计算三种潮洪组合工况下河口段水面线和流场变化。计算结果表明, 两种概化方式计算结果基本一致, 公园建设后河道地形和糙率发生变化, 导致水面线壅高和主流流速加大。阻力修正法计算的水面线壅高值稍偏大, 但仍低于左右岸防洪堤设计水位, 没有降低南渡江河口段防洪能力。司马坡岛附近局部出现高流速区, 有必要采取相应的防冲措施。 In order to predict and analyze the influence of the construction of Riverside West Park on the flood discharging capacity of the outlet section of Nandu River, we established a two-dimensional flow numerical model based on the hydrody namic model of MIKE21 FM. Firstly , we used the measured flood data of the hydrological stations to calibrate and verify the roughness coefficient of the main channel and tidal flats. We adopted local roughness correction method and local topographic correction method as the generalization methods of the park model. Then, we simulated the water level and flow field changes at the outlet section under three typical conditions of flood and tide combinations. The calculation results of the two generalization methods were basically consistent. The topography and roughness of the river channel would change after the park is built, leading to the increase of the water level and main flow velocity. The water level increase value calculated by the local roughness correction method was slightly larger, but the water level was still lower than the design water level of the flood embankment. The construction of the park would not reduce the discharging capacity of the outlet section of Nandu River. A high-velocity area would appear near Simapo Island. It is necessary to take corresponding measures to prevent scouring .