CMIP6⁃based meteorological drought characteristic study under climate change in the Hanjiang River Basin

To clarify the impact of climate change on meteorological drought characteristics in the Hanjiang River Basin, 10 climate models of CMIP6 were selected, considering historical scenario and four shared socioeconomic pathways (SSPs). The standardized precipitation evapotranspiration index was calculated and variation of meteorological drought characteristics was studied. The results indicate that the maximum difference between the annual precipitation and potential evapotranspiration in the Hanjiang River Basin in the future gradually increases, with a growth rate ranging from 0. 92 to 2. 40 mm/ a, while the minimum difference has different trends under different SSPs, with a relative decrease in SSP1-2. 6 and SSP3-7. 0 scenarios and a continuous increase in SSP2-4. 5 and SSP5-8. 5 scenarios. In the historical scenario, the cumulative drought duration in a year is shorter in the east and west, but longer in the middle of the basin. In SSPs scenarios, the cumulative drought duration in a year is expected to decrease in the middle and lower reaches, but increase slightly in the upper reaches, and droughts are likely to occur earlier in a year. In the future, the intensity of drought with short return periods will not change significantly, but the intensity of extreme drought will increase substantially, with a growth rate of 7. 1% to 25. 6% for drought with a return period of 100 years. © 2024 Editorial Board of Water Resources Protection. All rights reserved.