Spatiotemporal variability of drought in representative dry-hot valley regions of Southwest China
HUO Hong
ZHAO Xuan
LEI Wenwen
SUN Changping
Abstract：[Objective]Extreme weather events like drought are expected to become more frequent in the context of climate change.Studying and understanding its spatiotemporal variation and the underlying drivers is critical to mitigating its detrimental impact.This paper analyzes drought trends and their influencing factors in a representative region in Southwest China.[Method]The study region is the Jinsha-Yuan River dry-hot valley in Yunnan Province.Using land surface temperature and the normalized difference vegetation index,we constructed a temperature vegetation dryness Index(TVDI).We then integrated natural and anthropogenic factors,including annual mean temperature,precipitation,evapotranspiration,and nighttime light intensity,and applied piecewise linear regression,the Mann-Kendall test,Theil-Sen slope estimation,GeoDetector,and correlation analysis to investigate the spatiotemporal changes in TVDI from 2001 to 2020 in the region.[Result]Temporally,TVDI exhibited a generally decreasing trend though with fluctuations.However,a significant shift occurred in 2018,after which drought became worse.Spatially,48.1%of the area experienced moderate to severe drought,with Yuanmou,Huaping,Binchuan,and Yongren counties in the Jinsha River Basin and areas along the Yuan River identified as drought hotspots,which require priority monitoring and control.In contrast,there was less drought in Northeast and Northwest of the region.Temperature,altitude and evapotranspiration were the natural factors that affected drought variation the most,while human influence was relatively minor compared to natural factors.[Conclusion]From 2001 to 2020,drought conditions across the study area generally improved,though with notable spatial heterogeneity.Natural environmental variables played a key role in shaping drought dynamics,underscoring their importance in regional drought risk assessment and management.
Keywords：climate changedry-hot valleydrought variationdriving factorsdisaster prevention and control
Publication Date：2025-07-30
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：9( 80-88 )