State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin 300350, China; School of Civil Engineering, Tianjin University, Tianjin 300350, China; State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210029, China.
State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin 300350, China; School of Civil Engineering, Tianjin University, Tianjin 300350, China.
Sci Total Environ. 2022 Dec 20;853:158593. doi: 10.1016/j.scitotenv.2022.158593. Epub 2022 Sep 8.
Shallow lakes are greatly influenced by submerged aquatic vegetation (SAV), which affects hydraulic and water quality during their entire life cycle. An integrated model was developed based on the Environmental Fluid Dynamics Code (EFDC), which considers the dynamic bottom roughness and sediment release flux related to SAV growth and decomposition. Model results of hydrodynamics, water quality, and sediment-P release in Baiyangdian Lake (BL) were analyzed with and without the SAV module. The results showed that SAV played a critical and alterable role in regulating the internal loading in lakes. During the period of exponential growth, SAV reduced the velocity and sediment-P release in Zaozhadian by 20 % and 12 %, respectively. During the period of senescence, SAV reduced the velocity by 19 % and increased sediment-P release by 49 %, which was mainly attributed to dissolved oxygen (DO) consumption during residue decomposition. To mitigate the adverse effects of SAV on internal loading, measures should be taken to control the growth of SAV and ensure timely salvage before decomposition.
浅水湖泊受水下植被 (SAV) 的影响较大，水下植被在其整个生命周期中会影响水力学和水质。本研究基于环境流体动力学代码 (EFDC) 开发了一个综合模型，该模型考虑了与 SAV 生长和分解相关的动态底部粗糙度和泥沙释放通量。利用有无 SAV 模块的方法对白洋淀 (BL) 的水动力、水质和泥沙-P 释放进行了模型分析。结果表明，SAV 在调节湖泊内部负荷方面发挥了关键和可变的作用。在指数增长阶段，SAV 将枣子店的流速和泥沙-P 释放分别降低了 20%和 12%。在衰老阶段，SAV 将流速降低了 19%，并将泥沙-P 释放增加了 49%，这主要是由于残留物分解过程中耗氧量的增加。为了减轻 SAV 对内部负荷的不利影响，应采取措施控制 SAV 的生长，并在分解前及时进行打捞。
