基于MIKE21模型的汤逊湖水质水量模拟研究

Simulation on Water Quantity and Quality of Tangxun Lake by MIKE21 Model

近年来,作为亚洲最大的城中湖的汤逊湖面临着湖内水质急剧恶化的困境,对周边居民生活和城市景观造成了一定负面影响,其水质已不能满足水功能区管理要求,因而,亟需针对汤逊湖流域开展水环境综合治理。调研了汤逊湖污染源现状,对比了汤逊湖水环境容量,并利用MIKE21FM组件进行了汤逊湖的水动力-水质耦合模拟汤逊湖水质现状,在此基础上论证了内水系连通方案下水动力的改善情况,以及实施污染减排方案后从东坝河调水和非调水情景对汤逊湖水质的影响。结果表明:内水系连通对改善湖体水动力有重要作用;仅进行污染物削减对全湖水质提升效果有限,而当从东坝河引水10 m^(3)/s、同步进行内源、外源污染物削减时,全湖Ⅲ类水区域面积显著增加。

Tangxun Lake,as the largest lake within a city in Asia,has been facing rapidly deteriorating water quality in the past few years,causing negative impacts on surrounding citizens and city landscape,and its water quality fails to meet water functional zone requirements.Therefore,it is essential to implement comprehensive treatment of the water environment of Tangxun Lake.The current water pollution sources were investigated.Compared with the water environment capacity of Tangxun Lake,the MIKE21FM component was used to simulate the water quality of Tangxun Lake by coupling the hydrodynamics and water quality of Tangxun Lake.On this basis,the hydrodynamics of the internal water system connection scheme was demonstrated.A hydrodynamic simulation was conducted to evaluate the improvement of hydrodynamic after connecting the lake’s internal water system.Two scenarios with and without the water-diversion from the Dongba River were then simulated around the premise of a pollution reduction plan.It can be concluded that the pollution reduction plan is insufficient for promoting the overall quality of the lake,and a 10 m^(3)/s-water-diversion-plan from the Dongba River proves significant to enhance the proportion of the lake area reachingⅢassessment standards.