Vegetation in Arid Areas of the Loess Plateau Showed More Sensitivity of Water-Use Efficiency to Seasonal Drought

Studying the impact of regional or seasonal drought on vegetation water-use efficiency (WUE) can identify an effective theoretical basis by which cope with future climate change. Based remote sensing data and grid data, in this study, we calculated ecosystem WUE standardized precipitation evapotranspiration index (SPEI), analyzed temporal spatial divergence WUE, explored relationship between Loess Plateau. The results indicate that from 2001 to 2019, humidity spring summer Plateau shows increasing trend, aridity fall also trend. Averaged over four seasons, presents distribution characteristics “high southeast low northwest”, highest summer. However, geological sensitivity was significantly different. Spring increased whereas led a decrease WUE. When less severe, increased; response winter SPEI negative, but did not change variation degree. magnitude affected dry wet conditions. A clear found regions, along intensity, arid areas generally higher than semi-arid, semi-humid areas, humid areas. With deeply how ecosystems deal water supply strategy drought, is great significance understanding coupling carbon–water cycle