基于MIKE建模的城市生态公园行洪能力分析

目的]预测并分析工程对河道行洪能力变化的影响,为城市生态公园工程防洪影响评价提供研究技术方法。方法]基于MIKE 21建立城市生态公园工程河段的平面二维水流数学模型,以渭河宝鸡段为例,选取1954型洪水过程验证模型合理性,模拟3种典型流量下河道流场和水位的变化特征,讨论城市生态公园修建后对河道行洪能力的安全影响。结果]3种典型流量洪水下沿线水位均低于堤顶高程,对城市行洪安全不构成威胁,因此行洪安全可以保证。但由于河道行洪宽度变窄左岸流速增大,加剧了对岸堤的冲刷,采取岸堤加固措施是极为必要的。结论]河道形状的改变会影响水的流态,水流速度过大会影响河堤结构稳定性,最终影响河道的行洪能力。

Flood Discharging Capacity of Urban Ecological Park Based on MIKE Modeling

Objective] The study aims to predict and analyze the project impacts on the river flood discharging capacity, and provide methods for assessing flood controlling impacts of urban ecological park projects.Methods] Based on MIKE 21, we constructed a 2-dimension water flow model for urban ecological park section in Weihe River in Baoji City, selected 1954 flooding process to verify the rationality of the model, and simulated three typical flow characteristics of flow field and changes in water level and discuss the urban ecological park impacts on river flood discharging capacity. Results] Under the three typical flow flooding events, the water level along the river was below embankment and not a threat to urban flood discharging safety, and the flooding safety can be guaranteed. But as a result of flooding passage narrowing and increasing velocity, the erosion of the embankment was intensified, and reinforcement measures was urgently needed. Conclusion] The river shape will affect the flow regime. The higher water flow speed will affect the stability of embankment structure thus influencing the river flood discharging capacity.