Reference evapotranspiration change and its sensitivity to climate variables in southwest China

摘要: Reference evapotranspiration (ET0) is the key factor for hydrologic water balance, irrigation scheduling, and resources planning. Based on Food Agriculture Organization (FAO) Penman–Monteith method climate variables of 57 meteorological stations from 1960 to 2010 in southwest China, spatial temporal distributions ET0 were analyzed by using Mann–Kendall test Sen’s slope estimator. Sensitivity coefficient was used analyze sensitivities four variables, attributed change determined. Result showed that there a slight downward trend spatially increasing northeast annual time scale. Results also had relatively higher sensitivity wind speed mean air temperature, dominant variable China. The inverse relationship between temperature decreasing evaporation, “evaporation paradox,” existed negative contribution changes offset positive temperature.