气候变化下多年冻土融水对青藏高原径流影响评估  

Unsustainable water supply from thawing permafrost on the Tibetan Plateau in a changing climate

作　　者：王泰华 杨大文 杨雨亭 郑冠恒 金会军 李新 姚檀栋 程国栋 Taihua Wang;Dawen Yang;Yuting Yang;Guanheng Zheng;Huijun Jin;Xin Li;Tandong Yao;Guodong Cheng(State Key Laboratory of Hydroscience and Engineering,Department of Hydraulic Engineering,Tsinghua University,Beijing 100084,China;Institute of Cold Region Science and Engineering,School of Civil Engineering,Northeast Forestry University,Harbin 150040,China;State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;National Tibetan Plateau Data Center,Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China;Center for Excellence in Tibetan Plateau Earth Sciences,Chinese Academy of Sciences,Beijing 100101,China;Institute of Urban Study,Shanghai Normal University,Shanghai 200234,China)

机构地区：[1]State Key Laboratory of Hydroscience and Engineering,Department of Hydraulic Engineering,Tsinghua University,Beijing 100084,China [2]Institute of Cold Region Science and Engineering,School of Civil Engineering,Northeast Forestry University,Harbin 150040,China [3]State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China [4]National Tibetan Plateau Data Center,Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China [5]Center for Excellence in Tibetan Plateau Earth Sciences,Chinese Academy of Sciences,Beijing 100101,China [6]Institute of Urban Study,Shanghai Normal University,Shanghai 200234,China

出　　处：《Science Bulletin》2023年第11期1105-1108,M0003,共5页科学通报（英文版）

基　　金：the National Natural Science Foundation of China(42041004 and 52209027);the Strategic Priority Research Program of Chinese Academy of Sciences(XDA20100103);the support from the China Postdoctoral Science Foundation(2022M711857);the Postdoctoral Innovation Talents Support Program of China(BX2021166);the Shuimu Tsinghua Scholar Program;the financial support from the National Natural Science Foundation of China(42071029)。

摘　　要：青藏高原约40%的面积分布有多年冻土,相比冰川积雪融水得到的广泛关注,冻土融水对径流的影响仍有待评估.本研究基于耦合冰冻圈过程的分布式水文模型GBEHM(Geomorphology-based Ecohydrological Model),在区域尺度量化了多年冻土融水对径流的影响.研究结果表明:(1)过去40年间,青藏高原多年冻土面积下降13.9%,地下冰储量减少约401.1 Gt,约为同期冰川储量减少量的2倍;(2)多年冻土融水对全青藏高原总径流贡献相对较小(约0.5%),但在某些区域(如黄河上游、长江上游)和高程范围(如河西走廊4000m高程附近),地下冰融水对径流的贡献超过冰川融水贡献,其影响不可忽略;(3)气候变化背景下,地下冰融水径流在未来不可持续,澜沧江、怒江等区域历史阶段已经达到峰值,而对全青藏高原,融水径流拐点预计将在21世纪20年代(SSP1-2.6)、50年代(SSP2-4.5)或90年代(SSP5-8.5)达到.Rivers originating from the Tibetan Plateau(TP)provide water to almost one-fifth of the global population[1,2].Due to its high elevation,the TP features high dependence on cryospheric meltwater,including meltwater from snow,glaciers,and ground ice[3].In a warming climate,the sustainability of cryospheric meltwater on the TP has raised concerns because of its importance for the fragile ecosystems in the headwater regions.Existing studies mainly focused on glacier melt and snow melt on the TP[1,4,5],while the hydrological implications of thawing permafrost remain elusive.The TP has the world’s largest area of elevational permafrost,which features long-term preservation of ground ice that has formed since the Late Pleistocene[6].With ongoing climate warming,a large quantity of ground ice is likely to be mobilized and the meltwater could contribute to river runoff(Q)[7],which might also transport sediment and organic carbon fluxes[2].Existing large-scale hydrological modelling studies on the TP rarely include permafrost dynamics in their models[8,9].Therefore,the fate of ground ice and its hydrological implications across the entire TP remain largely unknown.

关 键 词：多年冻土 地下冰 分布式水文模型 融水径流 气候变化背景 冰冻圈 冰川融水 青藏高原 

分 类 号：P467[天文地球—大气科学及气象学] P333.1[天文地球—水文科学]