Water resources management and dynamic changes in water politics in the transboundary river basins of Central Asia

The growing water crisis in Central Asia (CA) and the complex water politics over the region's transboundary rivers have attracted considerable attention; however, they are yet to be studied in depth. Here, we used the Gini coefficient, water political events, and social network analysis to assess the matching degree between water and socioeconomic elements and analyze the dynamics of water politics in the transboundary river basins of CA. Results indicate that the mismatch between water and land resources is a precondition for conflict, with the average Gini coefficient between water and population, gross domestic product (GDP), and cropland measuring 0.19 (highly matched), 0.47 (relatively mismatched), and 0.61 (highly mismatched), respectively. Moreover, the Gini coefficient between water and cropland increased by 0.07 from 1997 to 2016, indicating an increasing mismatch. In general, a total of 591 water political events occurred in CA, with cooperation accounting for 89 % of all events. Water events have increased slightly over the past 70 years and shown three distinct stages, namely a stable period (1951-1991), a rapid increase and decline period (1991-2001), and a second stable period (2001-2018). Overall, water conflicts mainly occurred in summer and winter. Among the region's transboundary river basins, the Aral Sea basin experienced the strongest conflicts due to the competitive utilization of the Syr and Amu Darya rivers. Following the collapse of the former Soviet Union, the density of water conflictive and cooperative networks in CA increased by 0.18 and 0.36, respectively. Uzbekistan has the highest degree centrality in the conflictive network (6), while Kazakhstan has the highest degree centrality in the cooperative network (15), indicating that these two countries are the most interconnected with other countries. Our findings suggest that improving the water and land allocation systems and strengthening the water cooperative networks among countries will contribute to the elimination of conflicts and promotion of cooperation in CA.