Changes of reference crop evapotranspiration and pan evaporation in hinderland of Taklimakan Desert

Pan evaporation(Ep) and crop evapotranspiration(ET0),as a measurement of soil-plantation-atmosphere transfer system models,which influence the application of models and the precision of prediction,has traditionally been used for water use and water consumption of plant.The changing trend of pan evaporation and crop evapotranspiration are also attracting attention from the hydrological community worldwide due to its indicative meaning in hydrological cycles.In this article,compared the two results from Penman-Monteith formula and pan evaporation based on daily meteorological data from 2005-2010 of Tazhong weather station in hinderland of Taklimakan Desert,grey relational analysis was conducted characters of the pan evaporation,crop evapotranspiration and different effects of meteorological factors,and the correlations between ET0 and Ep were analyzed.The results indicate that there is the same trend in both crop evapotranspiration and pan evaporation of the years.The maximum of the ET0 appears in July and the minimum appears in January.However,the maximum of the Ep appears in June and the minimum appears in December.Meanwhile,the figures of reference crop evapotranspiroaion vary from 0.30 to 0.46.The grey relational analysis showed that there is a close correlation between ET0 and Umean,just ahead of Tmax.On the contrary,the pan evaporation is a strongly relation with Umean,then Umean.The scale of different seasons of ET0 and Ep has different affected of meteorological factors and the maximum meteorological factors of otherness appear the summer.The correlative analysis showed that there is a very significant correlation between ET0 and Ep with the spring,the autumn and the winter.Nevertheless,the relationships of ET0 and Ep are significant correlation in summer.The results of research are provided some scientific insights on the water use,water consumption of the shelterbelts along the Tarim Desert Highway as well as the management of groundwater.In addition,these results can also shed a light on the sustainability of shelterbelts along the Tarim Desert Highway.