Estimation of ecological baseflow with several hydrological methods at the Dahuangjiangkou reach of the Xijiang River

Daily streamflow data at Dahuangjiangkou Station of Xijiang River 1960-2017 were used to divide the streamflow sequence into two series with three mutation point test methods: Mann-Kendall test for series 1 before the interference of human activities (1960-1991) and series 2 after the interference (1992-2017)．In series 1, six hydrological methods including Tennant and NGPRP methods were used to estimate monthly ecological base flow．Compared with simulation of fish spawning habitat in the river, NGPRP method; was more applicable in the study area．Monthly ecological base flow value was estimated by NGPRP method; the guarantee degree of ecological base flow before and after the interference was analyzed and compared．The guarantee degree of ecological base flow was found to decrease from September to November after interference, but to increase in the remaining months．The large numbers of planned water conservancy facilities on the Xijiang River makes ecological environment protection a great challenge．The highly applicable hydrological calculation method used here provides some reference for the calculation of ecological base flow, to analyze assurance degree of ecological base flow before and after interference．