Spatial-Temporal Change of Actual Evapotranspiration and the Causes Based on the Advection–Aridity Model in the Weihe River Basin, China

Evapotranspiration is a key process between the atmospheric hydrological cycle and energy cycle, which has great significance in understanding climate change rational use of water resources, especially for Weihe River basin (WRB) (a China experiencing shortage resources). We investigated spatial-temporal actual evapotranspiration (ETa) based on daily meteorological variables 22 stations annual streamflow three from 1970 to 2018 WRB. The contributions ETa changes sensitivity coefficient are also quantified. temporal trends showed an increasing trend 2018, spatial distribution increased northwest southeast Increasing were detected multi-year average, spring, winter, but only few passed test. Summer autumn decreasing trend, this was not significant. Solar radiation most sensitive variable, followed by vapor pressure, wind speed, mean temperature. Vapor pressure contributes changes, solar radiation. In general, (relative humidity) dominant factor affecting addition factors, affected combined complicated factors caused precipitation human activities. As important part research resources management, economy, agriculture, ecology results study may be helpful further clarify activities impacts cycle.