大东湖水网连通的水动力与水环境变化响应

为揭示城市河湖水网连通工程的生态水文响应机制,以武汉大东湖水网连通工程中东湖-沙湖连通为例,建立水动力-水质耦合数学模型,模拟分析水网连通前后东湖、沙湖的水动力与水质变化,并从空间分布和时间变化两方面,分析水质变化与水动力变化的响应关系。结果表明:东湖-沙湖连通后,东湖与沙湖水动力条件改善较明显,TN浓度和TP浓度基本呈现下降的变化趋势;主流线附近水域流速增加,TN、TP浓度降低,水质改善效果较好;偏离主流线较远的水域,其流速、TN、TP浓度均变化不大;东湖子湖(汤菱湖、水果湖)、沙湖的TN、TP浓度变化过程与流速变化过程呈现负相关关系。

Hydrodynamic and water environmental response to Great Donghu Lake Water Network Connection Project

In order to reveal the eco-hydrological response mechanism of river-lake system network connection project, taking Donghu Lake-Shahu Lake connection of the Great Donghu Lake Water Network Project as the research object, a hydrodynamic and water quality lake model was established to assess the changes in flow and water quality before and after the implementation of water network connection project. Moreover, the corresponding relations in spatial distribution and time rhythm between the pollutants concentrations and flow field were studied. Results indicated that the hydrodynamic condition of Donghu Lake and Shahu Lake improved obviously, and concentration of TN and TP decreased. The velocity of water near the main stream increased, TN and TP concentrations decreased, and the effect of water quality improvement was better. The velocity, TN and TP concentration of the water far away from the main stream had little change. There was a negative correlation between the change of TN and TP concentration and the change of flow velocity in two sub-lakes of Donghu Lake(Tangling Lake, Shuiguohu Lake) and Shahu Lake.