Abstract:

The temporal pattern of precipitation and evapotranspiration in Wushen County, Mu Us Sandland from 1981 to 2003 has been studied by statistical and the remote sensing analysis methods. The result showed: 1) In main rainy season from June to August, the frequency of rainstorm is higher, rain permeated so quickly that very little runoff produced; 2)The mean annual evapotranspiration of the studied area is 252 mm, which is lower than precipitation slightly and decreases from the east to the west. The distribution of evapotranspiration for seasons was a single peak normal, and the peak value was in July and the hollow value were in January and December. The tends of evapotranspiration is similar to precipitation; 3) The relative rate of evapotranspiration in the studied area varied greatly in 10%～24%, displaying decreasing tends from the northwest to the southeast; 4) Based on the water quantity and the vegetation cover degree (0.7), the water resources revenue and expenditure,were in a dynamitic low level balance, but the non-uniformity of the precipitation distribution, the vulnerability and the transition of the sand ecosystem decreased validity of water resources, therefore, it is very important to adopt water-saving irrigation agricultural technologies to improve water use efficiency rate in fodder plantation.

Key words: Mu Us sandland, precipitation, evapotranspiration