Comparative Analysis of Reference Crop Evapotranspiration and Pan Evaporation of Taklimakan Desert Hinterland

Using the meteorological data of Taklimakan Desert Hinterland from 2005 to 2010, reference crop evapotranspiration (ET₀) of extreme arid region of Taklimakan Desert Hinterland was calculated with FAO Penman-monteith calculation method, and the comparative analysis was conducted with pan evaporation (Ø20) in the meteorological station, the influencing factors that had an effect on ET₀ and Ø20 meteorological factors were sequenced with the grey association degree analysis theory. The results were shown that ET₀ maximum value appeared in July, and the minimum value appeared in January; Ø20 maximum value appeared in June, and the minimum value appeared in December; monthly potential reference crop evapotranspiration coefficients ranged between 0.30 and 0.46. Grey correlation analysis showed that the meteorological factors that were most closely relationship with ET₀ was Umean, second was Tmax, while the meteorological factors that was most closely relationship with Ø20 was Tmax, second was Umean. The meteorological factors that affected ET₀ and Ø20 were different in the Spring, summer, autumn and winter, and the biggest difference between them appeared in summer. ET₀ presented highly significant linear relationship with Ø20 in spring, autumn and winter, while there was significant linear relationship in summer. The research results could provide theoretical support for the rational use of water resources and the sustainable development of Tarim desert highway shelterbelt.