Calculation methods for appropriate ecological flow

From the perspective of the characteristics of river ecosystem, this paper put forward to some new approaches to calculate the appropriate ecological flow with fish habitat and fish biomass.The method utilizes the long-term hydrological data to set up the relationship by traditional hydrological method; while the fish habitat method, according to the theory of stream rehabilitation ecology, namely calculating the appropriate ecological flow through the analysis of the relation between fish biomass and annual flow.Because of the shortage of the fish biomass data, the fishery quantities are replaced in this paper, and then with the relation between fishery quantities and flow, we can calculate the appropriate ecological flow.With the fish habitat method and the fish biomass method, the appropriate ecological flow of Songhuajiang river basin is studied.It shows that the results of the two methods are almost consistent.Commonly, the two methods can be considered as the validation for each other, the account error of the two methods is below 3%.Without the influence of backwater, the fish habitat method is adaptive to the rivers of various scales.Though the fish biomass method is usually adaptive to large floodplain river, it should be used with cautions for the small stream in mountains.