Long-term relative decline in evapotranspiration with increasing runoff on fractional land surfaces

Abstract. Evapotranspiration (ET) accompanied by water and heat transport in the hydrological cycle is a key component regulating surface aridity. Existing studies documenting changes aridity have typically estimated ET using semi-empirical equations or parameterizations of land processes, which are based on assumption that parameters equation stationary. However, plant physiological effects its responses to changing environment dynamically modifying ET, thereby challenging this limiting estimation long-term ET. In study, latent flux (ET energy units) sensible were retrieved for recent decades global scale machine learning approach driven ground observations from towers weather stations. This study resulted several findings; example, evaporative fraction (EF) – ratio available exhibited relatively decreasing trend fractional surfaces. particular, decrease EF was an increase runoff as assessed precipitation (P) minus accounting 27.06 % areas. The signs indicative reduced conductance, further emphasizes vegetation has major impacts cycles, well variability.