Adaptive calculation of river ecological flow considering the variable lifting volume under changing conditions

Abstract Ecological flow is a restrictive condition set for human water consumption in water resources management to protect river ecosystems. However, uncertainties in hydrological conditions, changes in regulatory capacity, and temporal-spatial differences bring difficulties to the implementation and supervision of ecological flows. By analyzing the relevant concept and connotation of ecological flow, it is concluded that the ecological flow regimes suitable for practical application should be a dynamic interval rather than a fixed value. Therefore, an improved ecological flow calculation method was proposed, which is to increase the feasible lifting volume for different ecological service objects based on the determined ecological baseflow. Taking two cross-sections of the Weihe River as an example, the ecological flow was calculated by comprehensively considering the factors of inflow, fish survival, landscape, and agricultural irrigation. The result shows the lifting volume occurred in the high flow season (April–June), and the maximum ecological flow of LJC and WJB cross-sections was 20.2 and 16.0 m3/s, respectively. Moreover, it is a generalized approach that can be extended to a more complicated river system, and the calculation results have reliability and adaptability in integrated water regulation.