Abstract: Aiming at the serious soil salinization in arid oasis, GIS and RS techniques were adopted to study the salinization characteristics in topsoil (0-20 cm) in an oasis at the lower reaches of the Sangong River Basin in the northern piedmont of the Tianshan Mountains in Xinjiang of Northwest China, and a spatial probability model was used to predict the dynamic status of the soil salinization. After a long-term land use process, the soil salinization in the study area aggravated to some extent, and the area of soil salinization was enlarged. The χ²test of spatial probability model revealed that the simulated value of transition probability and the measured value were more reliable during the period of 1982-2005 than during the period of 1982-1999. The simulated results of spatial probability model showed that after 2010, the area of natural landscapes was reduced, but that of artificial ones was enlarged, in which, the area of slight soil salinization was decreased, but that of moderate and serious soil salinization showed an opposite pattern. It was considered that within a long period, soil salinization would be still a key factor limiting the cropland productivity in the study area.

Key words: precipitation variation, water source, desert habitat, Nitraria sibirica., stable isotope