Abstract: Turpan Basin in Xinjiang is one of the regions of China's most arid climate and scarce water resource.Agriculture is totally dependent on mountain water runoff and groundwater irrigation.The research on reference crop evapotranspiration changes under the climate change background in the development of scientific and rational management of water resource technology program is of great significance.Based on the historical climate data of four meteorological stations from 1959 to 2007 in the Turpan Areas,the Penman-Monteith formula recommended by Food and Agriculture Organization(FAO) of the United Nations was used to calculate the reference crop evapotranspiration.The annual average temperature,precipitation,sunshine hours,wind speed,relative humidity and change trends and characteristics of the year's reference crop evapotranspiration in the last 49 years for each station were analyzed,by using linear regression,Morlet Wavelet and the Mann-Kendall mutation detection methods.The results showed that the average air temperature and relative humidity increased in the past 49 years in the Turpan Areas,while the sunshine hours and annual average wind speed decreased.But the precipitation did not change significantly.The reference crop evapotranspiration was closely related to the climate conditions(p<0.1),while it was positively related to the annual average wind speed,air relative humidity,rainfall and mean temperature(p<0.01).The overall reference crop evapotranspiration in the last 49 years in the Turpan Areas decreased(P<0.01).This would be important to reduce the crop water requirement and irrigation volume.The results by mutation examination showed that the mutant increase of the annual average temperature was in 1970 in Turpan region,while the mutant decrease of the annual average wind speed was in 1965.The mutant decrease of the reference crop evapotranspiration was in 1968.All of the climate elements and reference crop evapotranspiration had a quasi 2 to 8 years periodic change at the inter-annual scale and 16 to 24 years periodic change at the inter-decade scale.

Key words: Turpan Areas, Turpan Areas, Climate change, Reference crop evapotranspiration