Response of Multireservoir System on the Main Yellow River to Eco-Environment Flow Change

Ecological water demand is given great attention in water resources research field over the past decades. Many river administrations intend to put their hands to protect ecological flow in water resources management. But its influence on the existed interests created by reservoirs operation, become a main obstacle to carrying out the further work. Therefore the objective of this paper is to analyze the responding of cascade reservoir operation on the main Yellow River under different ecological water demand. To realize the research target, a simulation operation model of cascade reservoir was established in the study. Different ecoenvironment flow control plans were setting as the constraint conditions at the Hekouzhen cross section on the main Yellow River. Based on these Preliminary Works, the simulating regulation was put into force under different constraints, and the many result schemes were obtained by computing. Then through comparative analyzing the acquired schemes on the Yellow River, we knew that two statistics of water stress index (WSI) and ecological damage rate (EDR) was improved in 2020 level year, while other ones of water-supply guarantee rate (WSGR) and annual power generation (APG) were changing in a smaller percentage after eco-flow controlling. It is thus clear that eco-flow controlling will play an important role on ecological protection to the Yellow River within the coming 10 years, but hardly impact on cascade reservoirs power generation under appropriate actions. However, in the foreseeable future reservoir ecological regulation will relieve a great increasing of ecological damage rate from water competing, but if no drawing water resources from other basin, to meet ecological water demand of the Yellow River is still a greater difficulty.