Satellite-based alpine water dynamics response to climate change across the Tibetan Plateau

The spatiotemporal water dynamics across the Tibetan Plateau (TP) are important for sustainable utilization and management of water resources in Asia, particularly under the influence of climate change. However, comprehensive assessments of the long-term variations in lakes, marshlands, and terrestrial water storage (TWS) across the TP remain limited. This study utilized a long-term series of Landsat images of the TP to create annual lake maps with 30-m spatial resolution for the period 1990–2022, using a surface water frequency algorithm and Google Earth Engine (GEE). Based on the derived maps, the spatiotemporal trends of marshland area (MA) were analyzed. We also investigated changes in TWS from 2002 to 2022 using GRACE and GRACE-FO data products. Furthermore, we conducted a quantitative analysis of the drivers of changes in lake area (LA) and TWS. Results show that from 1990 to the 2020s, both LA and the number of lakes increased rapidly, with the most pronounced changes occurring in the Inner Plateau. In contrast, MA exhibited a declining trend during 1990–2020, also predominantly in the Inner Plateau. TWS exhibited an overall increasing trend, predominantly occurring in the Inner Plateau, where lakes are most densely distributed—mirroring the spatial pattern of lake expansion. The findings of this study could assist both the government and the general public in confronting the escalating challenges regarding water resources and water security in China.