Spring drought variability in Yunnan within Southwest China from 1580s to 2020s and its impacts on social unrest - Qian Li; Yinxian Shi; Zhenhua Li; Bin Liu; Hua Huang; Xuefei Yang; Jianchu Xu; Yingfeng Bi (Palaeogeography, Palaeoclimatology, Palaeoecology, 2026)