Future drought patterns in Southwest China: A CMIP6-based analysis using multiple drought indices

southwest China This study examines future drought patterns in Southwest China—a humid yet drought-prone region—focusing on trends in drought indices, changes in duration, frequency, and intensity, and their impacts on agriculture. Temperature and precipitation from 20 CMIP6 models were downscaled using the high-resolution China Meteorological Forcing Dataset (CMFD), and the multi-model ensemble was used to calculate four drought indices: Standardized Precipitation Index (SPI), China-Z Index (CZI), Standardized Precipitation Evapotranspiration Index (SPEI), and nonstationary SPEI (NSPEI). SPI and CZI indicate wetter trends under all SSPs, while SPEI and NSPEI project intensified drought risks, especially under SSP3–7.0 and SSP5–8.5. SPI and CZI show an "increase-then-decrease" pattern in frequency and duration, with stable intensity, while SPEI exhibits a "decrease-then-increase" trend across metrics. NSPEI reveals higher extremes and sustained increases in frequency and intensity. Over half of the cropland may be exposed to future droughts, particularly single rice (up to 29,446 km²), single maize (26,733 km²), and single wheat (6106 km²). The Sichuan Basin, as a persistent hotspot, may experience drought exposure of up to 17,755 km² for rice and 11,434 km² for maize. The findings highlight critical regional disparities and stress the urgency of drought adaptation strategies. • Divergent drought trends: SPI/CZI show wetting; SPEI/NSPEI predict drying. • Nonstationary NSPEI captures higher drought extremes and prolonged impacts. • Sichuan Basin emerges as the most drought-prone area under all scenarios. • More than half of the cropland may be exposed to future droughts.