In this paper, taking the Huangshui river basin of Qinghai province located in Qinghai-Tibetan Plateau and Loess Plateau as the study area, based on CLUE-S model, using land use data in 1987, 1996 and 2007, land use spatial distribution pattern and future scenarios was simulated. Firstly, 18 key driving factors including elevation, slope of between 0°-5°, 5°-15°, 15°-25° and > 25°, aspect(flat aspect, eastern aspect, southern aspect, western aspect and northern aspect), distance to rivers, distance to roads, distance to urban and rural residential areas, population, local financial revenue and so on, were selected by using logistic step-regression method; Secondly, land use data in 1987 and 1996 were used respectively to simulate the spatial pattern of land use in 2007 (the temporal scale was 20 years and 11 years respectively) for the Huangshui river basin. In the end, in order to validate simulation results of two temporal scale, simulated land use map in 2007 was respectively compared with actual land use map in 2007.The results showed that using CLUE-S model, at 250m spatial resolution level, the simulation accuracy reached respectively 88.31% and 89.96% at two temporal scale, and Kquality indices attained all 0.999, Klocation indices were 0.826 and 0.851 respectively, Kstandard indices were 0.826 and 0.851 respectively, Knoindices were 0.826 and 0.851 respectively, all Kappa indices were more than 0.82, which suggesting that CLUE-S model has a good applicability in simulating land use change in the Huangshui river basin and can be used to predict future land use change.
Focusing mainly on slope cultivated land change of the study area, four kinds different scenarios of land use change for future 20 years (from 2008 to 2027) were constructed, and land use spatial pattern in 2027 in the study area was stimulated under above different scenarios by using the CLUE-S model. The simulation results indicated that in 2027 urban and built-up land was significantly increased under all four kinds different scenarios, mainly distributing in valley regions of the study area,whereas there was obvious spatial difference in the slope cultivated land change under scenario Ⅱ,Ⅲ and Ⅳ, that is scenario Ⅱ > scenario Ⅲ > scenario Ⅳ. The returning slope cultivated land will distribute in Ledu county, Minhe county, Datong county and Huangyuan county. The increased area of forest land will mainly distribute in south and north mountains of Xining city. The study conclusions will provide data reference and basic information of decision support for watershed future land use planning, management and policy-making.