MIKE21模型对傀儡湖水动力与水质改善的应用研究

Research on the Application of Water Quality Improvement of Kuilei Lake using MIKE21 Model

傀儡湖为昆山市水源所在地,其水质受阳澄湖影响较大,近年来有恶化趋势,其中引水水质受季节性影响,夏季湖体易出现蓝藻爆发与氮磷超标现象,亟需对傀儡湖水质进行改善。作者调研了傀儡湖水质现状,并利用MIKE21 FM进行了傀儡湖的水动力-水质耦合模拟,论证了不同的水动力和水质改善方案的效果。可以得到结论如下:扩展引排水渠道的数量对湖体水动力影响不显著;建设河口湿地改善阳澄湖入湖水质、在傀儡湖湖体种植沉水植物对水质改善效果明显,联合采用上述措施可使夏季各类污染物浓度削减20%以上。

Kuilei Lake,as the source of water for Kunshan City,has been facing deteriorating water quality due to its main water supply,which is Yangcheng Lake.The diverted water from Yangcheng Lake varies with seasonality,and algae outbreak occurs during summer,along with the exceedance of water quality for nitrogen and phosphorus.The author investigated the water quality of Kuilei Lake and used MIKE21 FM to simulate the current hydrodynamic water quality of the lake,based on which multiple scenarios were established for simulating the hydrodynamic and water quality improvements.It can be concluded that the expansion of water diversion and drainage channels fails to significantly enhance the hydrodynamic situation of the lake.In comparison,introducing cleaner water from Yangcheng Lake by constructing an estuarine wetland,and planting submerged plants can be greatly beneficial to the water quality improvement of the lake,reducing at least 20%of pollutant concentration during summer.