Greening of the Taklamakan Desert: Effects of climate change and ecological water conveyance

Abstract

Oases in the Taklamakan Desert exist in an extremely arid region. Persistent droughts in the late 20th century nearly caused ecosystem collapse in the Lower Tarim River region. Since the implementation of ecological water conveyance in 2000, groundwater levels have increased, vegetation has flourished, and a marked “greening” trend has occurred throughout the oases. However, a quantitative analysis of the drivers of these changes is lacking. This study integrates multi-source remote sensing data and field monitoring, using random forest modeling and Geographical Detector to monitor shifts in vegetation cover and their causes in the lower Tarim River and surrounding oases since 2000. In this period, groundwater has increased by approximately 0.07 m·yr −1 , surface-water areas have expanded, and regional air temperatures, particularly in winter, have increased markedly. Oasis vegetation cover has also increased significantly, while cropland has expanded markedly. Although natural vegetation has generally improved, cropland growth has encroached on desert riparian forests, intensifying interspecific competition within these communities and increasing potential ecological risks. Moreover, groundwater recovery and cold-season warming are key influencing factors associated with oasis greening, while recurrent droughts and interactions between climatic and hydrological variables further shape vegetation growth. Cumulatively, this study shows that effective water management supports oasis greening in arid areas, while highlighting the ecological risks of over-farming. Overall, this study provides new insights into how arid ecosystems respond to coupled climatic and anthropogenic drivers, and offers scientific support for ecological water-delivery regulation, agricultural water-use optimization, and riparian habitat conservation.