Description:
Improving hydrodynamic conditions is considered an effective method for facilitating the eutrophication management. However, the limiting effect of hydrodynamic conditions on algal growth has rarely been quantified. In this work, a eutrophication model was developed and flow velocity was introduced into the algae growth kinetic formula to simulate the dynamics of algae growth in an estuary drinking water source reservoir of East China. Based on the previous research and model calibration, the flow velocity function f(v) and its parameters were determined. Accordingly, the optimal flow velocity for the dominant algae growth and critical flow velocity for algal growth inhibition were presented to be 0.055 m/s and 0.200 m/s for the study reservoir. Modeled results considering f(v) corresponded better with observations and reproduced the algal overgrowth process more accurately. The spatial-temporal differences in chlorophyll a (Chl a) concentration distribution during the algal proliferation period were analyzed on basis of simulation results, which corroborated the significant influence of flow velocity on algal growth. The established model was applied to investigate the effect of reservoir hydrodynamic promotion on algal bloom control, and the scenario simulation of the additional sluice was conducted. Results showed that the additional sluice operation inhibited algal overgrowth effectively, resulting in an average decrease of 24.8%, 3.3%, 43.0%, and 37.5% in modeled Chl a concentrations upstream north, upstream south, midstream and downstream, respectively. The established model will provide scientific and practical references for eutrophication management in the study reservoir and other water bodies with similar hydrological characteristics and geographical features