Study on the methods for quantifying the environmental flow in estuaries
河口生态环境需水量计算方法研究

Considering the requirement of the water cycle, the biological cycle and the habitat in estuaries, the methods for quantifying the environmental flow with different functions and the temporal variation respectively are presented. Annual water demands are determined based on the adding and the maximum principle. Month variation of environmental flow is settled to be close to the variation of natural river discharge. Different levels are established in case of the limited requirement for ecological water demands. Calculating methods for quantifying the environmental flow in estuaries are applied in Haihe River Basin. The results indicated that the minimum ecological water demands for Haihe estuary, Luanhe estuary and Zhangweixin estuary were 5.97×108 m3, 6.81×108 m3 and 4.96×108 m3 respectively. Sediment transport will be impacted directly by the reduction of the river discharge, and the balance of salinity will be changed in the estuarine ecosystem.