| The Mu Us Sandland climate changes significantly in recent years. It has a greater impact on the exploitation and utilization of water resources, economic construction and farming. Through studying the effects of climate change on reference crop evapotranspiration(ET0) of the Mu Us Sandland, scientific basis could be provided to the water demand of crops in the area, and reference could be supplied to reasonable exploitation or effective management of water resource. Besides, the study can also guide industrial structure adjustment of agriculture and animal husbandry, the agricultural development model, the formulate of farming system and other things about agriculture. so that we can serve the economic construction better.In this paper, by referring to relevant literature and collecting relevant meteorological data from the China Meteorological Data Sharing Service Internet, the ET0 of month and year in Mu Us Sandland were calculated with formula of FAO56Penman-Monteith. By means of mathematical statistics method, tendency analytic method of Mann-Kendall, anomaly and et al, the trend and fluctuation range of each meteorological factor and ET0 in each month and the whole year were analyzed, based on daily meteorological data of 5 weather stations nearby(Yulin, Hengshan, Yanchi,Etuokeqi, Dongsheng) from 1959 to 2013. By ArcGIS software, the daily meteorological datum of 30 years from 1981 to 2010 in 9 weather stations(4 more stations named Dingbian, Jingbian, Shenmu, Yijinhuoluoqi besides the stations mentioned before) were interpolated and the spatial distribution and fluctuation range of each meteorological factor and ET0 in Mu Us Sandland were analysed. Through the way of sensibility and drought index analysis, the main meteorological factors that effect ET0 were finded out and the degree were predicted. The results show:(1) On the whole, climate in Mu Us Sandland is warm and dry. Temperature went up suddenly in 1986; Vapour pressure went down in 1971 and went up in 2001 all of a sudden. There are no sudden change for other meteorological factors.(2)The spatial distribution of different meteorological factors in Mu Us Sandland is different. The precipitation,temperature, relative humidity and vapour pressure inreduce from southeast to northwest. Wind velocity increases from from northeast to southwest. Sunshine duration increases from southeast to northwest. For range of fluctuation, the precipitation reduces from northeast to southwest. The average temperature is relatively high in northeast but relatively low in south-central. The wind velocity reduces from northwest to southeast. The relative humidity is relatively high in south-central while low in northwest.The sunshine duration is relatively long in east-centre, but relatively short in northeast and southwest.(3) ET0 of recent 55 years shows a downward trend.Spatially, it goes down from southwest to northeast and the range of variation decreases from northwest to southeast. The value of ET0 is 887.22~1092.28 mm. The average number is 1011.30 mm. The maximum of ET0 appears in June with an average of 5.24 mm.The minimum appears in December with an average of 0.66 mm.(4)The influence degree of different meteorological factors on ET0 at different time periods is different. Relative humidity and vapour pressure has a large effect on ET0 and the temperature has a small influence. The influence of sunshine duration and wind velocity on ET0 is in the middle. The influence of sunshine duration from April to September on ET0 is larger than that of relative humidity, and the effect is reverse.The value of ET0 and its change rate reduce as temperature and relative humidity go up, and the value increase as wind velocity, vapour pressure and sunshine duration increase. The drought index general "up- gently- down" trend from 1959 to 2013. |
