Glacier changes and their impact on glacial lakes in the Parlung Zangbo Basin, Southeastern Qinghai-Tibetan Plateau, 1987–2023

There is a dearth of accurate multitemporal glacier change investigations and analyses in the Parlung Zangbo Basin (PLZB) of the Southeastern Qinghai-Tibetan Plateau. A combination of deep learning and artificial visual interpretation was employed to investigate the glaciers in the PLZB since 1987 using multisource and multitemporal data. The impact of climate change on glaciers retreat, and the impact of glaciers retreat on the risk of glacial lake outburst floods (GLOFs) were revealed and assessed. From 1987 to 2023, a total of 1,505 to 1,702 glaciers, encompassing a total area of 1,693.94 km² to 1,068.24 km², were identified in the PLZB. The glacier area has continued to shrink, with a shrinkage rate of 16.99 km²/yr (1.01 %/yr). The PLZB is one of the fastest glaciers retreat region in China. The distribution of glaciers in the PLZB exhibits the typical characteristics of mountain glaciers. The number of small glaciers is considerable and increasing, and the average elevation of the glaciers is over 5,000 m and rising. East- and northeast-facing glaciers are the most numerous, north-facing glaciers are exceedingly scarce. The principal factor driving the accelerated retreat of the glaciers was the rapid rise in temperature. The accelerated retreat of glaciers has contributed to the formation and expansion of glacial lakes and may have increased the potential risk of GLOFs. It is imperative that the residents of the PLZB and even the Qinghai-Tibetan Plateau enhance their capacity to prevent and withstand GLOFs.