Sustainable environmental flow management based on lake quality protection: The case of Baiyangdian Lake, China

Water shortages and quality deterioration are serious dilemmas for lake managers as both problems sharply decrease the ecosystem services and functions provided by a lake. In this paper, using WASP as a tool, we have established and calibrated a water quality simulation model for Baiyangdian Lake and then analyzed water quality variations in scenarios with different pollution load reductions and different environmental flow releases into the lake and discovered the sustainable schemes for environmental flow management. From the results, in the scenarios of 30%, 50%, and 90% pollutant load reduction, the sustainable environmental flows are 3.52, 3.13, and 2.12 m3/s, and the corresponding lake levels could attain 7.45 m, 7.35 m, and 7.05 m from the initial 6.0 m. The obtained results indicated that water release could improve the lake volume and quality simultaneously.