黄河下游引黄灌区水系连通条件下水环境变化效应模拟

Simulation of Variation Effect of Water Environment Under Water System Connectivity in Yellow River Downstream Irrigation Area

赵口引黄灌区二期工程新建总干渠—运粮河—涡河和东二干渠—陈留分干渠—惠济河输水通道,以提升灌区连通性,形成有效的输配水网络。为分析水系连通条件下灌区水环境变化效应,基于灌区二期工程范围内河、沟、渠基本构架及水文、水生态环境多项指标监测数据,利用MIKE11软件中水动力模块和对流扩散模块,构建灌区水动力-水质耦合模型,模拟灌区水系水量、水质动态变化,解析水系连通工程对灌区退水受纳水体涡河和惠济河水环境的影响。结果表明,水系连通后涡河和惠济河TN、TP、NH+4-N和NO-3-N的浓度降低,水环境容量增大。水系连通工程建设可促进灌区水系水循环,提升水体可再生性,提高灌区退水受纳水体水环境质量。

The second phase project of the Zhaokou Yellow River Diversion Irrigation Area involved the construction of the main canal⁃Yun⁃liang River⁃Guohe River and the Dong’er Main Canal⁃Chenliu Branch Canal⁃Huiji River water transmission channel for enhancing the con⁃nectivity of the irrigation area and formed an effective water transmission and distribution network.In order to analyze the effect of water envi⁃ronment change in the irrigated area under the condition of water system connectivity,based on the basic structure of rivers,ditches and ca⁃nals and monitoring data of hydrology and water ecological environment indicators within the scope of the second phase project of the irrigated area,the hydrodynamic and water quality coupling model was constructed by using the hydrodynamic module and advection⁃dispersion module in the MIKE11 software.The dynamic changes of water quantity and water quality in the irrigated area were simulated and the impact of water system connectivity engineering on the environment of the receiving water bodies of the Guohe River And Huiji River in irrigation areas was analyzed.The results show that after the water system is connected,the concentrations of TN,TP,NH+4⁃N and NO-3⁃N in the Guohe River and Huiji River are decreased,and the water environmental capacity is increased.The construction of water system connectivity projects can promote the water cycle of irrigation areas,enhance the renewable nature of water bodies,and improve the water environment quality of the receiving water bodies for water withdrawal in irrigation areas.