Spatio-Temporal Evolution of Glacial Lakes in the Tibetan Plateau over the Past 30 Years

As the Third Pole of the Earth and the Water Tower of Asia, the Tibetan Plateau (TP) nurtures large numbers of glacial lakes, which are sensitive to global climate change. These lakes modulate the freshwater ecosystem in the region but concurrently pose severe threats to the valley population by means of sudden glacial lake outbursts and consequent floods (GLOFs). The lack of high-resolution multi-temporal inventory of glacial lakes in TP hampers a better understanding and prediction of the future trend and risk of glacial lakes. Here, we created a multi-temporal inventory of glacial lakes in TP using a 30-year record of 42,833 satellite images (1990-2019), and we discussed their characteristics and spatio-temporal evolution over the years. Results showed that their number and area had increased by 3285 and 258.82 km(2) in the last 3 decades, respectively. We noticed that different regions of the TP exhibited varying change rates in glacial lake size; most regions show a trend of expansion and increase in glacial lakes, while some regions show a trend of decreasing such as the western Pamir and the eastern Hindu Kush. The mapping uncertainty is about 17.5%, which is lower than other available datasets, thus making our inventory reliable for the spatio-temporal evolution analysis of glacial lakes in the TP. Our lake inventory data are publicly published, it can help to study climate change-glacier-glacial lake-GLOF interactions in the Third Pole and serve as input to various hydro-climatic studies.

Automated summary

As the Third Pole of the Earth and the Water Tower of Asia, the Tibetan Plateau (TP) plays a vital role in regional freshwater ecosystem. However, the increase in glacial lakes due to global climate change increases the risk of sudden glacial lake outbursts and consequent floods, posing severe threats to the valley population. This study created a high-resolution multi-temporal inventory of glacial lakes in TP using satellite images from 1990 to 2019, showing an overall increase in number and area of glacial lakes. This inventory provides valuable data for studying climate change-glacier-glacial lake-GLOF interactions and hydro-climatic studies.