Research on eco-environmental flow based on the improved holistic method and its application in Wei River Basin

Water use of the ecosystem in the Wei River has been greatly reduced because of fierce competition between social-economic and eco-environmental water use, which leads to serious eco-environmental issues. Stakeholder theory was applied to the water resources utilization, and an improved holistic method for determining the eco-environmental flow was proposed. Considering the principles of inflow of tributaries, water intake from key sections, water balance and eco-environmental function regionalization, the new method integrated several methods to determine the water demand for the sub-items of eco-environmental flow. The three-level management targets of eco-environmental flow were proposed based on the opinions of stakeholders. Taking Shaanxi Section of the Wei River as an example, the eco-environmental flow at different levels was given for five key sections. The results show that: (1) the improved holistic method integrates multiple methods and models, making the calculation results of eco-environmental flow more scientific and reasonable; (2) the three-level management targets of eco-environmental flow can adapt to development and change in practical applications, and are operable and dynamic; (3) as a representative of the public benefits of ecosystems, government participates in the discussion of stakeholders and better coordinates competition among stakeholders. The improved method provides a new idea and reference for comprehensively and scientifically promoting reservoir ecological regulation.