Spatial–temporal variations and response mechanisms of groundwater storage anomalies in Central Asia under global warming

Five Central Asia (CA) countries, including Kazakhstan (KAZ), Kyrgyzstan (KGZ), Uzbekistan (UZB), Tajikistan (TJK) and Turkmenistan (TKM), as well as Xinjiang (XJ), China. Groundwater depletion is widespread in arid regions such as CA, especially in the context of global warming and population growth. To achieve rational use and management of groundwater resources in CA, it is essential to understand the changes in groundwater storage and the response mechanisms influenced by climate and human activities. This study analyzed these aspects using statistical and correlation methods. The study shows a three-stage trend of GWSA in CA: “decline-rise-decline” (–0.45 mm/yr from 2002 to 2008, +0.29 mm/yr from 2009 to 2017, and –0.01 mm/yr after 2018), especially in KAZ, KGZ, and UZB, indicating dynamic changes in regional groundwater. The significant decline in groundwater storage is likely due to increased water consumption from arable land expansion and rising air temperatures (GWSA positively correlated with precipitation and negatively correlated with agricultural and domestic water withdrawals), while the sharp increase is probably related to water resource policies in CA. The results suggest opportunities to enhance groundwater recharge during rainy periods and the risk of over-exploitation. Recommendations include establishing a climate-resilient water management system, adopting water-saving technologies, and enhancing transboundary cooperation to ensure sustainable regional water resource utilization. • Analysis of groundwater storage anomalies (GWSAs) in Central Asia (CA) in 2002–2020. • GWSAs in CA exhibited a decrease–increase–decrease trend in the last 19 years. • GWSAs were significantly and positively affected by pre and negatively by AWW and DWW.