Spatio-temporal evolution characteristics and response relationship between precipitation and surface water resources in Yunnan Province from 2000 to 2022

In order to clarify the trend and evolutionary relationship between precipitation and surface water resources in Yunnan Province, the temporal and spatial evolution of precipitation and surface water resources and their inter-relationships from 2000 to 2022 were systematically analyzed with Pearson correlation analysis, cumulative anomaly and the Mann-Kendall test.The study showed that the province′s precipitation was in a weak decreasing trend (-0.8%), while the surface water resources decay was more significant (-7.64%), and both of them showed the stage characteristics of fluctuating rise (from 2000 to 2008), sharp decline (from 2008 to 2014), and smooth recovery (from 2014 to 2022), with the mutation points in 2001 and 2003, respectively.In terms of spatial distribution, due to the storage effect of karst landforms, the precipitation and surface water resources in east Yunnan increased by 1.94% and 1.57% respectively, against the trend from 2000 to 2022 compared to 2000 to 2010, while west Yunnan and central Yunnan declined significantly.There were significant regional differences in the conversion efficiency of precipitation-surface water resources (east Yunnan > central Yunnan > southern Yunnan > western Yunnan).Among them, the highest transformation efficiency was in eastern Yunnan (with a slope of 0.25), and the lowest in western Yunnan (with a slope of 0.08).The results of the study can provide a reference for the zoning management of water resources and cross-border river cooperation in Yunnan Province, and it is suggested to take differentiated regulation measures according to the characteristics of different regions.