Quantifying the effects of submerged aquatic vegetation on internal loading in lake: A modeling study of the largest shallow lake in North China br

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 releaseflux related to SAV growth and decom-position. Model results of hydrodynamics, water quality, and sediment-P release in Baiyangdian Lake (BL) were ana-lyzed 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-Prelease 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) consump-tion during residue decomposition. To mitigate the adverse effects of SAV on internal loading, measures should betaken to control the growth of SAV and ensure timely salvage before decomposition

Automated summary

Shallow lakes are greatly influenced by submerged aquatic vegetation (SAV) which affects the hydraulic and water quality. An integrated model based on the EFDC was developed to analyze the impact of SAV on hydrodynamics, water quality, and sediment-P release in Baiyangdian Lake (BL). The results showed that SAV played a critical role in regulating internal loading, but measures should be taken to control SAV growth and ensure timely salvage to mitigate adverse effects.