Threshold identification of evapotranspiration under different land-use types in the Loess Plateau, China

Study region Loess Plateau (LP), China Study focus Evapotranspiration (ET) is crucial in the terrestrial hydrological cycle and serves as a vital indicator of water resource availability. However, the interactions between ET and vegetation, climate, and soil on the LP have been left unexplored, especially during the growing season and regarding ET thresholds for different land-use types. Therefore, we used ridge regression and geographic detector model to analyze ET response to fractional vegetation coverage (FVC), temperature, precipitation, land surface temperature (LST), and temperature vegetation dryness index (TVDI). Additionally, the elastic coefficient was used to determine the ET thresholds for dominant factors in different land-use types. New hydrological insight for the region The study reveals FVC as the dominant factor driving ET changes, while also highlighting the synergistic effects of temperature, precipitation, LST, and TVDI with FVC. The synchronization of ET and FVC change trends in vegetation unchanged and restored areas underscores the significance of vegetation cover in regulating regional water cycles. Furthermore, the study provides valuable insights into the regional water cycle dynamics and offers a certain level of guidance for water management strategies tailored to different land-use types.