Scientists Verified the Evolution Characteristics and Drivers of Groundwater in the Oasis of Dried-up River in Tarim Basin
Groundwater is crucial for the development of artificial oasis. With the increasing intensity of climate change and human activities, the river in Tarim Basin of China’s northwestern Xinjiang is severely dried-up, and the contradictions between water resource, ecology and economy in the areas are very prominent. The continuous decline of groundwater level has brought severe challenges to regional water resources and ecological security. Human activities have significantly altered the natural groundwater cycling process in the oasis. So, what happened to groundwater in the middle and lower reaches of dried-up river?
Researchers from the State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, elaborated the spatiotemporal variations and controlling factors of groundwater level and mineralization degree using data collected at 22 wells in the Wei-Ku Oasis of Tarim Basin during 2000-2018. Additionally, standardized partial regression coefficient and spatial multiple linear regression analysis were used to evaluate the response of groundwater to human activities and climate variability.
Results showed that obviously large spatial and temporal variations existed in both groundwater level and mineralization degree, and its response to environmental factors varied in space and season. Groundwater level was the shallowest in spring and deepest in autumn, and exhibited a markedly decreasing trend (2.05 m per decade), mainly due to human activity. While groundwater mineralization degree marginally decreased (-0.21 g/L·10a), mainly due to climate change. Larger variation of groundwater level depth/ mineralization degree generally occurred at the areas with greater groundwater level depth/ mineralization degree. Decreasing riverbank leakage and increasing volume of evapotranspiration, groundwater pumping and water drainage led to decreasing groundwater level. Furthermore, a conceptual diagram was given to systematically depict groundwater variations associated with climatic and anthropogenic impacts in the arid oasis of Tarim Basin.
The research results were published in the Journal of Hydrology, entitled "Evolution characteristics of groundwater and its response to climate and land-cover changes in the oasis of dried-up river in Tarim Basin".
Figure 1 Conceptual diagram depicting groundwater variation due to climate change and anthropogenic activities in the typical oasis of Tarim Basin.
Contact: LIU Jie, Xinjiang Institute of Ecology and Geography