摘要
采用MIKE FLOOD模型建立了茅洲河河口一、二维耦合的水动力、水质模型,模拟分析茅洲河河口建闸后对茅洲河干流及河口附近水质的影响。通过模型模拟表明,由于茅洲河干流中下游的污染物以及交椅湾地形的影响,交椅湾内水体流速变慢,茅洲河河口易形成污染带。通过茅洲河河口建闸前后的工况模拟分析,共和村断面在2020年工况下洪水期氨氮浓度在1.6~2.3 mg/L之间波动,均值为2 mg/L,建闸后基本稳定在2.13 mg/L。枯水期时建闸前氨氮浓度在1.4~2.1 mg/L之间波动,均值为1.8 mg/L,建闸后基本稳定在1.83 mg/L。研究发现,河口闸的建设对茅洲河干流的水质基本没有改善作用。从污染物均值来看,河口建闸后闸上水质略有恶化,主要原因是河口处靠近外海区域污染物浓度较干流下游浓度低,建闸后闸址下游河水无法上溯,对断面污染物的稀释作用减小。本研究成果可供茅洲河水环境治理的相关决策提供参考,也可为其他流域的河口闸建设研究提供参考。
Based on the MIKE FLOOD,the 1-D and 2-D coupling hydrodynamic mathematical models of Maozhou River Estuary are established for simulating the impact from the sluice construction at the Maozhou River Estuary on the water quality therein.It is indicated through the model simulation that the flowing velocity of the water body inside Jiaoyi Bay becomes slower due to the impacts from the pollutants in the middle and lower reaches of the main stream of Maozhou River and the topography of the Jiaoyi Bay,thus a pollution zone is prone to be formed at the estuary of Maozhou River.Through the simulative analyses made on the operation conditions before and after the sluice construction at the estuary of Maozhouhe River,the ammonia nitrogen concentration at the river channel cross-section of Gonghe Village fluctuates between 1.6 mg/L and 2.3 mg/L with a mean value of 2 mg/L,which is basically stabilized at 1.83 mg/L.The study finds out that the construction of the estuary sluice has basically no any effect for improving the water quality of the main stream of Maozhouhe River.From the aspect of the mean values of pollutants,the water quality above the sluice is slightly deteriorated after the construction of the sluice,for which the main reason is that the pollutant concentration at the estuary near the open sea is lower than that at the downstream reach of the main stream,while the downstream river water behind the sluice cannot flow up and then the diluting effect on the cross-sectional pollutants is reduced as well.The study result can provide a reference not only for the relevant decision-making for the water environment improvement of Maozhouhe River,but also for the constructions of estuary sluices in the other river basins.
作者
林蓉璇
王鑫
徐辉荣
LIN Rongxuan;WANG Xin;XU Huirong(Guangdong Hydropower Planning & Design Institute, Guangzhou 510635, Guangdong, China)
出处
《水利水电技术》
北大核心
2020年第8期140-151,共12页
Water Resources and Hydropower Engineering
基金
国家重点研发计划项目“珠江河口与河网演变机制及治理研究”(2016YFC0402605)。
