干旱区生态环境知识资源中心

Changes in the area of sandy desert and sandy land (SDSL) result from changes in the processes that underlie aeolian desertifica-tion. The area of SDSL in northern China has changed greatly in recent decades. Given that SDSL covers large areas of northern China, it is important to understand the spatial and temporal trends in its development and recession for understanding the aeolian desertification. To provide this information, we reconstructed the underlying processes of SDSL from 1975 to 2010 using Landsat images and an analysis of the driving forces. The results indicated that the changes of SDSL have mainly occurred in the eastern part of northern China. The area of SDSL increased by 58,455 km(2) from 1975 to 2000, increasing by 4.9%. In contrast, the sandy land has been restored, and the area of SDSL had a decreasing trend since 2000. It decreased by 17,600 km(2) from 2000 to 2010, decreasing by 1.4%. These changes were principally driven by human activities and climate variability. Since changes of the area of SDSL were not significantly related to natural environmental factors such as rainfall and temperature, it is clear that the decreasing trend of SDSL has been mainly caused by human activities.