青藏高原冰前湖与冰川相互作用研究进展

Progress in the study on the interaction between proglacial lake and lake-terminating glacier over the Qinghai-Tibet Plateau

基于已有研究,对青藏高原地区冰川与冰湖(主要为冰前湖)相互作用的机理研究进行梳理,以理解青藏高原冰川后退与冰湖扩张的过程和模式,加深对冰川与冰湖相互作用过程和机理的认识。青藏高原地区冰前湖主要分布于藏东南喜马拉雅山和念青唐古拉山,有记录和查明冰湖溃决成因的事件中,冰川动态引起冰前湖溃决事件占到冰湖溃决总事件的55%,且多分布于喜马拉雅山和念青唐古拉山等藏东南地区。冰川与冰前湖的相互作用模式表现为:冰川对冰前湖的作用和冰前湖对冰川的反作用。其中,冰川对冰湖的作用主要包括冰川退缩为冰湖发育提供了空间、冰川融水为冰湖形成和扩张提供了充足水源、冰川极端事件(冰面/内水系溃决、冰川前进/运动、冰崩等)引起冰湖溃决;冰前湖对冰川的反馈机制体现在冰前湖对冰川的热力融冰、冰前湖动力过程导致末端冰川崩解等物质亏损、冰前湖的演变对母冰川的气候效应。需要说明的是,二者之间的相互作用不是孤立的,是彼此依存、同时发生。未来冰川与冰前湖研究中,应致力于:(1)建立统一的冰川观测规范和冰湖-冰川数据集;(2)集成“气候-冰川-冰湖-灾害”为一体的综合观测体系,实现数据共享;(3)耦合冰川与冰湖模型,模拟相互作用过程与机制;(4)统一冰湖溃决灾害的评价体系和完善预警机制。此外,冰川与冰湖变化的理论相对成熟,但冰川与冰前湖相互作用的理论研究依然不够,亟需不断完善。

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 glacierlake 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.