Quantifying the climate and human impacts on the hydrology of the Yalong River Basin using two approaches

Abstract

AbstractRunoff in many river basins worldwide has shown an alteration under the impact of global climate change and increasing human activities. A detailed quantitative and qualitative analysis on the impact of climate change and human activities is therefore of great significance towards the sustainable water resources planning and management. In this study, the impact of climate change and human activities on the runoff was first quantitatively analyzed for the Yalong River Basin (YRB), China, by using a combination of the CREST hydrologic model and the Choudhury–Yang equation based elastic coefficient method, respectively. Furthermore, a qualitative analysis on the response of runoff to human activities was carried out in terms of land use changes, water withdrawal and reservoir operation. Results indicate that precipitation and runoff of the Yalong River Basin increased and decreased at the rate of 1.17 and 0.35 mm/a, respectively, for the period from 1980 to 2018. Climate change and human activities contributed 6.65–21.67% and 78.33–93.35% to the runoff variation, respectively. Among the human activities, we found that reservoir construction and operation is likely to be the major driver of the variation in the hydrologic regime of the YRB. Our methods and findings are expected to provide implications for water resources planning and management for the YRB and different basins across the globe.