Study on water regime assessment and prediction of stream flow based on an improved RVA

Abstract

Abstract Considering that many hydrological analysis methods compare and analyze the runoff before and after the construction of the reservoir, without restoring the measured data of the hydrological station, in this case, when the length of the measured data series is short, the evaluation results will be affected. In this article, based on the runoff reduction of stations affected by water conservancy projects, an improved range of variability approach (RVA) which can be applied to 1-year hydrological change analysis is proposed by coupling the hydrological variation index with the appropriate upper and lower limit theory of RVA. As Jialing river watershed is selected as the research area, the runoff depth of Beibei station is reduced, and then the improved RVA is employed to analyze the degree of change in river water regime. It is concluded that the change degree of overall hydrological index in Beibei station is high, and the prediction of variation of water regime of Beibei station can be made with the aid of simulating the operation of cascade reservoirs, with the inflow of Beibei station in flood season to reduce, and the inflow in dry season to increase. The example verifies the effectiveness of the improved RVA method, and the analysis results can provide a reference for the adjustment of the operation mode of upstream cascade reservoirs.