Sensitivity and Attribution of Potential Evapotranspiration in Western Liaoning

GUO Jinlu; GU Jian; YANG Zhuzhu

doi:10.13522/j.cnki.ggps.2016.0225

Abstract：[Objective]Study the relationship between ET0and meteorological factors in a region with specific cli-mate.[Method]Based on the meteorological dataset during 1965 to 2015 from the thirteen selected meteorologi-cal stations of the western Liaoning, the FAO-56 Penman-Monteith method was used to estimate the reference evapotranspiration(ET0).The variation trend of meteorological variables and ET0were examined with the Mann-Kendall trend test.Besides,according to sensitivity coefficient,sensitivity of ET0to meteorological variables and the dominate factor which affects the variation of ET0were analyzed.[Result]The results showed the average ET0in western Liaoning was 1 007.6 mm/a,decreased at the rate of 12.5 mm/10 a in 1965—2015 and observed a low-high-low distribution pattern from the southwest to northeast. Daily maximum and minimum temperature were significantly increased.Wind speed and solar radiation were significantly decreased and relative humidity didn't significantly change. Sensitivity of ET0to meteorological variables were ranked as: relative humidity>maximum air temperature>wind speed>solar radiation>minimum air temperature.And ET0was negatively corre-lation with relative humidity,while other meteorological variables showed positive correlation.Contribution rate analysis showed the increased minimum,maximum temperature and decreased relative humidity impacted posi-tively to ET0variation,and the decreased wind speed and solar radiation impacted negatively.The largest contribu-tion rate to ET0variation was wind speed,while the relative humidity was lowest.[Conclusion]In general,the de-creased wind speed was the dominant factor to the ET0variation in western Liaoning.