Evaluating the Dynamics of Groundwater Depletion for an Arid Land in the Tarim Basin, China

Groundwater depletion has become a hotly debated topic, particularly in arid land. In this study, groundwater depletion and its dynamic factors were investigated in the Tarim Basin. The groundwater data were collected randomly from 10 groundwater monitoring wells, from September 2002-December 2014. Piezometric groundwater level decreased with the range from 667.00 cm to 1288.50 cm, and also with a linear decreasing rate of 73.96 cm per year, on average. Significant spatial variation characteristics have been detected. Groundwater depletion was more serious in the northwest than the southeast of the study area. A correlation analysis was conducted to explore the major influence factors. These results showed that the annual irrigated land area was the primary influencing factor. Driving force analysis also suggested that electricity consumption could be an effective and convenient factor to assess groundwater exploitation. This study indicated that human activity was the major impact factor for groundwater decline. The seasonal-trend decomposition analysis supported these findings, as observed from the correlation analysis and the spatial variation. It also provided new insight into the groundwater time-series and enhanced the identification of groundwater-flow characteristics. These findings may be useful for understanding the groundwater fluctuations in high water demand regions and also for developing safety policies for groundwater management.