Estimation of runoff and hydrological drought in the Jinsha River Basin based on CMIP6

In response to the frequent occurrence of water and drought disasters in the Jinsha River Basin in recent years, which pose a serious threat to water and energy security, 11 global climate models (GCMs) based on CMIP6 were coupled with the VIC hydrological model to estimate the trend of runoff changes in the Jinsha River Basin from 2030 to 2099. The standardized runoff index (SRI) was used to explore the evolution trend of future hydrological drought in the basin. The results show that the spacial downscaling effect of GCMs in historical period (1966-2014) and the runoff simulation effect of the VIC model are both good, providing reliable runoff and hydrological drought estimate data. The future runoff of the Jinsha River Basin shows a significant increasing trend, with Xiaodeshi Station having the fastest growth rate, followed by Pingshan Station, and Shigu Station having the slowest. The trend rate of SSP5-8.5 scenario is greater than that of SSP2-4.5 scenario. The Jinsha River Basin will show a trend of wetting in the future, with severe hydrological drought in the near future (2030-2064) and weakening in the far future (2065-2099). From a spatial perspective, the drought frequency, duration, and intensity of Shigu and Pingshan stations on the main stream of the Jinsha River are higher than those of Xiaodeshi stations on the tributary of the Yalong River. © 2023, Editorial Board of Water Resources Protection. All rights reserved.