Assessing the Coordination Degree of Coupled Human–Water–Ecosystem in the Tarim River Basin of China

To understand the current status of water resource utilization and explore the coordination degree of the coupled human–water–ecosystem in the Tarim River Basin, we used the water shortage rates and index of WUE to analyze the dynamic changes in water shortage and water use efficiency. We also applied the Gini coefficient to study the evolutionary trend of the degree of matching between water consumption and GDP in each sector. Based on the above analysis, we developed a human–water–ecosystem coupling coordination degree model incorporating various indicators relevant to the three subsystems to quantitatively assess the coupled and coordinated development status of the three subsystems of the human–water–ecosystem in the basin from 2004 to 2020. The main findings are as follows: (1) The Tarim River Basin suffers from water shortage in dry years, with a prominent supply–demand contradiction. In the severe drought years of 2009 and 2014, the water shortage rates reached 10.20% and 10.93%, respectively. (2) From 2004 to 2020, the Tarim River Basin’s water use efficiency (WUE), and its five prefectures showed a clear upward trend. On a multi-year average, Bayingol Mongolian Autonomous Prefecture had the highest WUE, while the Hotan region had the lowest. (3) The multi-year average value of the match between water consumption and GDP for the entire basin is 0.28. By industry, the primary industry’s match between water consumption and GDP is higher, while the secondary and tertiary industries have lower matches. (4) From 2004 to 2020, the coordination degree of coupled human–water–ecosystem in the five prefectures showed different degrees of upward trend, generally developing towards better coordination. In terms of multi-year averages, Bayingol Mongolian Autonomous Prefecture, located in the east, has the highest degree of coupled coordination. Meanwhile, Hotan, in the south, lags significantly behind the remaining four regions. Therefore, the Tarim River Basin should further improve and optimize the development model of sustainable water resource use.