Monitoring and analysis of aeolian desertification dynamics from 1975 to 2010 in the Heihe River Basin, northwestern China

Abstract

The Heihe River Basin is the second largest inland river basin in the arid region of northwestern China, and aeolian desertification is one of the most serious environmental issues it faces. Monitoring and analysis of the dynamics of aeolian desertification in this region could improve the understanding of its status and developmental trajectory, which is important for establishing effective and reasonable countermeasures. Based on a combination of multi-temporal Landsat images and GIS analysis, the temporal and spatial evolutions of aeolian desertification in the Heihe River Basin from 1975 to 2010 were reconstructed using visual interpretation methods. The driving force behind aeolian desertification and its sensitivity to climate change and human activities was clarified based on local meteorological and hydrographic data. The results showed that in 2010, aeolian desertified land covered 10,528.07 km2 (8.2 %) of the study area and most aeolian desertification was classified as severe or extremely severe. The expansion of the area of aeolian desertified land was gradual from 1975 to 2000, but it then decreased rapidly from 2000 to 2010. Climatic variability showed similar trends to that of aeolian desertification during the study period; however, excessive and uncontrolled water use due to an increase in the cultivated area, agricultural irrigation, and construction of water conservancy facilities was the main cause of aeolian desertification. Political measures are the principal factors behind the alleviation of desertification, and its reversal can be the result of the implementation of integrated water management and comprehensive environmental protection and restoration projects.