Regional assessment of the potential risks of rapid lake expansion impacting on the Tibetan human living environment

High-altitude inland lakes on the Tibetan Plateau (TP) play a crucial role in maintaining the water balance of Asian water towers and are the key indicators of climate change and variability. Over the past several decades, dramatic lake expansions in the endorheric Tibetan basins have exerted pronounced influences on the environmental changes of the unique highland. However, the potential influences of rapid lake growth on human living environment were rarely reported. The objective of this study is to analyze the influence or potential risk of rapid lake expansion on the living environment (including settlements and transportation facility) of the TP by referring to the recent lake growth rate since the early 21st century. This study examines the change characteristics of 139 Tibetan terminal lakes larger than 1 km² from 2000 to 2018, and shows that the area and water storage of these examined lakes increased by 2,737.40 km² and 89.37 km³, respectively, from 2000 to 2018. Furthermore, we assessed the submerging risk levels and potential influences of the rapid lake expansions on the local living environment by disentangling different lake drainage basins and administrative units, focusing on residential areas and road networks. The results indicate that 393 residential settlements and 393.90 km of road segments will be probably submerged within the next 20 years. The predicted high-risk townships might mainly concentrate in the southern and central parts of the Nagqu Prefecture, including Rongma, Qiangma, and Beila Townships. The study provides essential scientific references for evaluating the potential threats of lake growth on local people in Tibet and taking risk mitigation actions under the context of climate change.