| Yutian oasis is located in arid and semi-arid land, where there are less rain, ecological environment is fragile and the soil salinization is quite common. The soil salinization is accompanied by desertification, even they promote mutually and changes into one another. Therefore, the soil salinization becomes a threat to the sustainable development of economy and the security of ecology. In this paper, author chose the Karki village, the typical area in Yutian oasis, for study area, and investigated the spatial differentiation of the soil salinity in this area.In this paper, author set 61 samples in the study area, and measured the soil salt content and the soluble salt ions (CI-,SO42-, CO32-,HCO3- , Ca2+, Mg2+, K++Na+)of 7soil levels (0-5cm, 5-10cm, 10-20cm, 20-30cm, 30-50cm, 50-70cm, 70-100cm).Analyzed the spatial differentiation of the soil salinity in the study area by using geo-statistical software ArcGIS and mapping software AutoCAD. Based on the Kriging Difference Method, author carried on optimal estimation to the soil salt and salt ions of these samples which is not measured, and drew the spatial distribution chart of the soil salt content, its chemical types and the degree of salinization in the study area by using mapping software. Accordingly reflects the spatial distribution rules of soil salt content, its chemical types and the salinization degree more intuitiouistically. The result by analysising is that:⑴Investigated the spatial differentiation of soil salinity in study area, discovered that the variety range of soil salinity in topsoil is the largest one, and the variety range of soil salinity in soil levels over 20cm are larger than those of other soil levels. The variety range of soil salinity in those soil levels under 20cm is not so large. Soil salinity put up a strong variability from top to the down.⑵Tthis paper analyzed the spatial variability of soil salinity. From the various parameters of semivariogram, discovered that: soil salinity in 0-5cm soil level express strong spatial relativity; the soil salinity in 5-10cm, 10-20cm, 20-30cm, 70-100cm soil levels express medium spatial relativity; the soil salinity in 30-50cm, 50-70cm soil levels express weak spatial relativity.⑶Analyzed the spatial distribution rules of soil salt content. The horizontal distribution rules of soil salt content in the top soil levels (soil levels over 30cm) on the east-west direction is: increase first, then decrease, and increase again, then decrease again. The distribution rules of soil salt content in the down soil levels (soil levels under 30cm) is: decrease gradually from east to west. The distribution rules on the north-south direction are: soil salt content on the both sides is large, it is of the midsection is smaller, it shows U shaped distribution. The vertical distribution rules is: the total trend of soil salinity is to decrease. And the variation range of the vertical distribution of soil salinity is not large; it is almost a straight line.⑷Classified the chemical types of soil salinity drew its distribution map. Discovered the distribution rules of chemical types of soil salinity is:soil salinity all around the study area is mainly NaCl included NaSO4;soil salinity in the south parts of the midsection is mainly CaSO4,CaCl2; soil salinity in the north parts of the midsection is mainly Mg SO4,MgCl2.⑸Classified the degree of salinization in the study area, and drew its distribution map. The results showed its distribution rules as following: the salinization degree is quite serious all around the study area, but it is less serious in the midsection. Solinized land is distributed everywhere in the study area.⑹Drew the spatial distribution map of soil salt content in the study area and analyzed it. Discovered that the soil salt contents in the north part of the study area is larger than those of the south part of the study area. The variability of soil salt content in various sample points is decreased gradually along with the increase of soil depth. The variation range of soil salt content in the east part of the study area is larger than it is of the west part. In some cropland in the midsection, the soil salinity decreases first along with the increase of soil depth, and then it increases a little.This paper analyzed the spatial distribution rules of soil salinity of sampling points through using statistical software and GIS. According to the results of analysis, drew the spatial distribution map of soil salinity in study area. This would offer some basis to the research of salinization in this study area and some theoretic basis to the improvement of soil salinization and construction of channels.
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