Analysis of Water Yield Changes from 1981 to 2018 Using an Improved Mann-Kendall Test

Water yield (WY) refers to the difference between precipitation and evapotranspiration (ET), which is vital for available terrestrial water. Climate change has led significant changes in on a global scale, will affect WY. Nevertheless, how WY changed during past few decades factors dominated are not fully understood. In this study, based climate reanalysis remote sensing data, spatial temporal patterns of were revisited from 1981 2018 globally using an improved Mann-Kendall trend test method with permutation test. The response ET also investigated. results show that multi-year mean 297.4 mm/a. Based traditional test, showed (p < 0.05) increase 5.72% total valid grid cells, while it decrease 7.68% those. After correction calibration method, significantly increasing decreasing areas reduced by 10.52% 10.58% them, respectively. correction, confirmed mainly located Africa, eastern North America Siberia, parts Asia Oceania, dominant factor precipitation, was combined effect evapotranspiration. achievements study beneficial improving understanding hydrological variables context change.