The Evaporation Change Rates Characteristics and Its Influencing Factors

The paper researches evaporation trends and main influencing factors on basis of climate data in Jianping region of West Liaoning over nearly 60 years, with linear trending change and methods of correlation coefficient, regression analysis, and the others. It is shown from the results: From 1953 to 2012, the annual evaporation is trending to decrease. In which, the annual evaporation decreases averagely by about 49mm every 10 years; In field crop growing season from April to September the evaporation decreases by about 47mm every 10 years; In 1983 and 1984, the evaporation occurred big climate change, and the evaporation decreases by about 164mm after the big change; In field crop growing season, the evaporation decreases by about 145mm. Sunshine hours, diurnal temperature, mean minimum temperature, mean wind speed, relative humidity and vapor pressure and other factors are significantly correlated with evaporation, in which, sunshine hours, diurnal temperature, mean minimum temperature, mean wind speed are completely correlated with evaporation,on a correlation ratio of 0.437, 0.316, 0.270 and 0.295 respectively. The paper establishes a multiple regression equation with main influencing factors, and fitting results are basically consistent with local evaporation measured values with accuracy rate of 83.8%.