Assessment of Desertification Using Time Series Analysis of Hyper-temporal Vegetation Indicator in Inner Mongolia

Desertification is one of the serious threats to the environment in arid and semi-arid northern China. In order to understand inter-annual vegetation dynamics, vegetation indicators have been widely used in desertification assessment. In this study, rain use efficiency (RUE) derived from hyper-temporal remote sensing images has been used for desertification assessment. Based on time-series analysis, this study focused on how the desertification developed in Inner Mongolia and how the desertification reversed in the extremely arid environment. Results showed that during the past 11 years, there was no significant desertification development in Inner Mongolia. Parts of area showed a significant increase trend of RUE, especially in the eastern part of Ordos Plateau and southern Daqing Mountain, as well as the region from the Greater Hinggan Mountains to northern Yanshan Mountains. It is indicated that the ecological conditions in these areas have tended to be much better than before. The reason may be that the vegetation protection policies adopted in northern China have exerted a positive effect on the local environment. The results also showed that there was a significant relationship between rainfall and vegetation restoration, areas with more precipitation tend to be more easily restored, especially in the areas with more 300 mm precipitation. In addition, the research on desertification reversion showed that the desert edge region in western Inner Mongolia have changed intensively, and desertification reverse assessment needs to be further examined.