Assessment of Grassland Ecological Restoration Project in Xilin Gol Grassland
锡林郭勒草原生态恢复工程效果的评价

Xilin Gol grassland has been experiencing severe degradation since the livestock kept on increasing in the past decades. Recent 'Grassland Ecological Restoration Project' is being developed for improvement of the degraded grassland and sustainable development. However,due to the short-time of the project implementation,it is difficult to monitor the restored area and assess the effect of the project. In this study,SPOT-VGT maximum value composite (MVC) NDVI temporal series data from 1999 to 2004 of Xilin Gol was used to model climate-vegetation response relationships in pixel scale. The model was based on the maximum NDVI in the neighborhood and their climate factors including accumulated temperature and accumulated precipitation. Then the restored areas were identified by positive trend of normalized residuals between model predicted NDVI and actual values. The result was validated by grazing pressure index (GPI),which was defined as the sheep unit divided by NPP. Negative relationship was found between the trend of residual and GPI at county level,which proved the effectiveness of the method for short-term temporal data.