城市人工浅水湖泊群水系连通方案研究

城市大规模小型人工湖泊湿地群的建设,改变了水系水动力特性及污染物质迁移、扩散和转化过程。构建了包含状态变量、常数、作用力、进程、辅助变量和衍生变量等的一维河网和二维浅水湖泊水生态模型,确定敏感参数值,采用清潩河流域实测数据验证模型的准确性。模拟得到不同换水频率、不同恒定流量和不同波动流量等换水方式下人工湖泊的流场和水质浓度场,揭示了多种河湖水系连通方案下湖泊水动力特性和污染物质迁移转化规律。进一步结合多种方案下湖泊污染物质削减量和出水水质,组合优化水系连通方案。研究结果表明:彩用循环+换水的调控模式,控制清潩河流域湖泊群循环流量在0.03～0.20 m~3/s,换水次数选择每年的3,7月和11月统一换水3次,此时水系连通效果最优。

Interconnected water network scheme for urban artificial shallow lake group

Construction of small artificial lakes have affected the hydrodynamic characteristics, migration, diffusion and transformation processes of pollutants in the water network. Therefore, we constructed a aquatic ecological model of one-dimensional river network and two-dimensional shallow lake in this paper. The model included state variables, constants, diriven forces, processes, auxiliary variables and derivative variables. The measured data from Qingyi River Basin was used to verify the aquatic ecological model. The flow and water quality distribution in the lake under different water exchange frequency, water exchange modes namely constant flow rate and fluctuating flow rate mode were simulated in order to reveal the hydrodynamic characteristics and pollutants migration and transformation laws in the lake. Combining with the pollutant reduction with effluent quality, we proposed the optimal scheme for water network connection. The results show that using the regulation mode of combining circulation with water exchange, controlling the circulation flows of the lake group between 0.03 m3/s and 0.20 m3/s in Qingyi River Basin and changing water three times in March, July and November every year, the water network connection is the most effective.