Alpine wetland is one of the important types of land cover on the Qinghai-Tibetan Plateau, which connects different geospheres of the plateau and plays an important role and value for maintaining the function of the plateau ecosystem. The inherent characteristics of wetland system and the special natural geographical environment of the plateau determine that the plateau wetland ecosystem is sensitive to climate change. Previous studies have shown that the types of wetlands in the Qinghai-Tibetan Plateau are diverse, but there are large discrepancies between studies, the response of wetlands to climate change shows significant temporal and spatial differences and typological differences, the comprehensive ecological functions of plateau wetlands need to be scientifically evaluated, and the lack of wetland-related thematic data products limit the in-depth research on wetlands, especially, in the fields of carbon cycle and biodiversity conservation. In the future, it is necessary to strengthen the synthesis of multi-source technology, interdisciplinary cross-research, and launch the simulation of environmental effects of wetland changes and quantitative assessment studies of ecological functions, and so on, which are suggesting to provide scientific support for the sustainable management of alpine wetlands.

This paper reviews the mechanisms of interaction between glaciers and glacial lakes (mainly proglacial lakes) on the Qinghai-Tibet Plateau (QTP) based on existing research. It aims to understand the processes and patterns of glacier retreat and proglacial lake expansion on the QTP and deepen the understanding of the interaction mechanisms between glaciers and proglacial lakes. Proglacial lakes on the QTP are mainly distributed in the southeastern region over QTP, particularly in the Himalayas and Nyainqentanglha Mountains. Of the recorded and identified reason of glacial lake outburst flood events, 55% are caused by glacier dynamics, predominantly in the southeastern QTP including the Himalayas and the Nyainqentanglha Mountains. The interaction pattern between glaciers and proglacial lakes includes the effects of glaciers on proglacial lakes and the feedback of proglacial lakes on contacted glaciers. The effects of glaciers on glacial lakes mainly include providing space for the development of glacial lakes through glacier retreat, supplying abundant water sources for the formation and expansion of glacial lakes through glacier meltwater, and causing glacial lake outburst floods due to extreme glacier events, e.g. ice surface/internal water system outbursts, glacier advances/movements, ice avalanches. The feedback mechanisms of proglacial lakes on glaciers involve thermal melting of glaciers by proglacial lakes, mass loss from ice calving on the terminal glacier caused by dynamic processes of proglacial lakes, and the local climate effects of the evolution of proglacial lakes on their parent glaciers. It is important to note that the interaction between the two is not isolated but mutually dependent and simultaneous. Future research on glacier and proglacial lake should focus on: (1) Establishing unified glacier observation standards and glacier-lake datasets; (2) Integrating a comprehensive observation system that encompasses “climate-glacier-glacial lake-disaster” and sharing those observation datasets; (3) Coupling glacier and glacial lake models to quantify interaction processes and understand their mechanisms; (4) Standardizing the evaluation system for glacial lake outburst flood disasters and improving early warning mechanisms. Besides, the theories of glacier and glacial lake changes are relatively mature, while the theoretical research on the interactions between glaciers and proglacial lakes is still insufficient and urgently needs further development.

In order to explore the impact of climate change on the changes in lakes in the southwest of Nagqu, Tibet, the characteristics of lake changes and their relationship with climate factors were analyzed based on the 1976-2022 Landsat series of remote sensing image data. The results showed that the total area of lakes in 1976-2022 showed a significant expansion trend, at a rate of 6.96 km²/a (P<0.001). Compared with 1976, the lake area increased by 234.29 km² in 2022, with the largest expansion of 144.44 km² in 2000-2010, accounting for 64.46% of the total expansion; and the smallest expansion of 7.98 km² in 2010-2020, accounting for only 3.56% of the total expansion. Changes in lake water level and water volume are basically the same as the lake area. The lake area are very significantly correlated with temperature, maximum frozen soil depth of the research area (P<0.01). The increase in temperature has caused the thawing of permafrost and the continuous expansion of the lake area. The influence of precipitation on expansion is staged.

The spatiotemporal heterogeneity at the onset of the Tibetan Plateau (TP) rainy season and its related evolutions of atmospheric circulation were investigated from 1979 to 2019 based on precipitation datasets from the surface observations and ECMWF. Results show that: (1) TP’s rainy season exhibits three precipitation centers respectively in the central-eastern, southern, and northern regions, with significant discrepancies in their rain process, precipitation concentration period, and precipitation. (2) There exists a bimodal distribution in the annual variation of precipitation over the central-eastern TP, with a remarkable increase around the 27th pentad. The onset of rainy season is accompanied by the weakened westerly stream in the mid-latitudes region, the convergence of the Southwest Monsoon from the Bay of Bengal and the west coast of Indian on the southern edge of the plateau, and the enhanced water vapor transport under southwestlies. However, an increase in precipitation appears at the 32nd pentad over the southern TP, manifesting an unimodal distribution. The corresponding atmospheric circulation pattern involves the northward movement of westerlies, convection development in the Indian Peninsula, and water vapor intrusion in the middle troposphere. In the northern TP, the annual change in precipitation is unimodal, and the increase in precipitation starts at the 29th pentad. The onset of its rainy season corresponds to the westward- and northeard-stretching of East Asian westerly jet, and intensive wind shear over the plateau. (3) It should be pointed out that water vapor flux at the onset of rainy season is mainly transported across the south and west boundaries in the central-eastern and southern subregions but north and west edges over the northern part of TP. The increases in the northward transport flux of water vapor and regional moisture budgets in the plateau region jointly have contributed to an earlier onset of the TP rainy season in the past decades.