A method to calculate ecological flow base by coupling multi-species flow velocity requirement

Ecological restorations of river are key to sustainable economic development. Ecological water demand is a prerequisite for river ecosystem stability. Ecological water demand is widely investigated in ecology, hydrology and in water resources studies. Different methods have been used to calculate eco-flow. The lack of data on coupling of flow velocity demand for multiple species in existing methods is likely to have an impact on the accuracy of calculations and consequently on water resources regulation. In the present work, dominance index was used to establish a coupling model of multi-species ecological velocity, to provide a solution to ecological water requirement calculation. This method will not be affected by regional factors, and has wide applicability. Eco-flow at Huangtai Bridge was found to be 12.33 m³·s^-1, Chahe 4.40 m³·s^-1, and Shicun 14.53 m³·s^-1. Compared with the Tennant method, the present method produces reasonable data and can reflect the actual demand of fish population rather than individual species.