Evolution trends and driving factors of groundwater storage, recharge, and discharge in the Qinghai-Tibet Plateau: Study progress and challenges

The Qinghai-Tibetan Plateau is rich in groundwater storage, which maintain surface runoff and water supply security during the dry season. Climate warming is driving groundwater evolution, altering the water balance and ecological stability of Asia's water towers. This study synthesizes the literature analysis and identifies the groundwater quantity evolution dynamics in the Qinghai-Tibetan Plateau dominated by climate change and synergized by various regional drivers. Research dynamics and methods for groundwater storage were assessed, with most studies finding that changes in precipitation evapotranspiration pushed groundwater storage to decrease in the south and increase in the north, with an overall increasing trend. The trends and drivers of groundwater storage changes still need to be further verified due to differences in calculation methods and data sources. Numerous studies have demonstrated that changes in climate and permafrost are important drivers of groundwater quantity evolution. Reducing the uncertainty of model parameters and improving the understanding of groundwater movement and environmental change processes to improve groundwater flow simulation. This remains a top priority for the study of groundwater quantity evolution processes and trends in the Qinghai-Tibetan Plateau. Despite the remarkable progress of current research, studies and monitoring of regional groundwater evolution are still missing or inadequate, especially in environmentally hostile and sparsely populated areas. We propose three considerations for future research, combining satellite remote sensing data and enhanced water cycle monitoring elements and densities, coupling multivariate data such as isotopes to develop advanced coupled cryosphere-groundwater numerical modeling methods, and considering various ecological and environmental effects arising from groundwater quantity evolution. To provide information for the establishment of effective policies for ecosystem maintenance and sustainable water resource management in the global alpine water tower region.