Terrestrial evapotranspiration (ET) serves as a critical nexus between the hydrological cycle and energy process, which is highly sensitive to climate change (CC) and underlying characteristic change (ULCC), particularly in the regions with rapid environmental changes. This study designed a data combination scheme for investigating the ET variation and quantifying its drivers in the Yellow River Basin (YRB), using a simplified water–energy partitioning (WEP) method based on nine multi-source ET, precipitation and potential ET datasets. Results reveal that all ET datasets demonstrate significant increasing trends with the rates of 0.82–2.04 mm/yr2 during the period of 1982–2022, and the ET increments are 13.4–45.2 mm/yr from the base period (1982–2000) to the change period (2001–2022). For the whole YRB, ULCC has slightly larger averaged absolute and relative contribution (15.8 mm/yr and 52.9%) than those of CC (12.2 mm/yr and 47.1%) to ET increases among the different dataset triplets. For most sub-basins, ULCC exhibits higher contributions than CC, with relative contributions of nearly two-thirds, although considerable variabilities exist in their absolute contributions. However, the opposite results occur in the source region of the YRB, where CC has a primary contribution to ET variation. In summary, while ULCC is the primary driver of ET increases, its estimated contributions entail substantial uncertainty. In contrast, CC acts as a secondary driver, exhibiting greater robustness and lower sensitivity to multi-source dataset variability. This study provides a valuable multi-source-dataset-based ET attribution framework with the WEP method that advances our understanding of hydrological responses to the changing environment in the YRB.
Wang et al. (Mon,) studied this question.