Impacts of permafrost degradation on streamflow in the northern Himalayas

Fan, Linfeng1; Ji, Fang2; Kuang, Xingxing3; Guo, Zhilin3; Zhang, Rui1,4; Zheng, Chunmiao3,4

2024-06-01

10.1007/s11430-023-1297-4

SCIENCE CHINA-EARTH SCIENCES   影响因子和分区

1674-7313

1869-1897

The Himalayan water tower provides crucial water resources for Asia. Permafrost degradation is deemed to exert important impacts on streamflow in the Himalayan rivers. Yet, the magnitudes of such impacts remain poorly quantified. Here, we established a robust hydrological model that incorporated active layer deepening and ground ice melt for the drainage basin of the largest river in the northern Himalayas-the Yarlung Zangbo River (YZR). We estimated that permafrost degradation led to similar to 0.65 km3/yr decrease in surface runoff and similar to 0.35 km3/yr increase in baseflow and ground ice melt contributed similar to 0.25% to the annual streamflow in the YZR for the period 2001-2022. The "fill-and-spill" mechanism helps explain the seeming contradiction of observed increasing versus decreasing baseflow in different permafrost regions worldwide. We propose that the dilution of riverine dissolved organic carbon (DOC) concentrations by baseflow may lead to the riverine DOC hysteresis patterns. This study not only lays solid scientific basis for water resources management in the Himalayas, but also yields new insights into how to interpret measured river discharge and nutrient flux in permafrost regions over the globe.

Permafrost degradation Hydrology Streamflow Surface runoff Groundwater Himalayas

SCI ; EI

英语

通讯

National Natural Science Foundation of China[92047202] ; Science and Technology Research Program of the Institute of Mountain Hazards and Environment, Chinese Academy of Sciences[IMHE-ZDRW-03]

Geology

Geosciences, Multidisciplinary

WOS:001223447700001

SCIENCE PRESS

Web of Science

1.Chinese Acad Sci, Inst Mt Hazards & Environm, State Key Lab Mt Hazards & Engn Resilience, Chengdu 610041, Peoples R China
2.Hohai Univ, Yangtze Inst Conservat & Dev, Nanjing 210024, Peoples R China
3.Southern Univ Sci & Technol, Sch Environm Sci & Engn, Shenzhen 518055, Peoples R China
4.Eastern Inst Adv Study, Ningbo 315200, Peoples R China

Fan, Linfeng,Ji, Fang,Kuang, Xingxing,et al. Impacts of permafrost degradation on streamflow in the northern Himalayas[J]. SCIENCE CHINA-EARTH SCIENCES,2024,67(6).

Fan, Linfeng,Ji, Fang,Kuang, Xingxing,Guo, Zhilin,Zhang, Rui,&Zheng, Chunmiao.(2024).Impacts of permafrost degradation on streamflow in the northern Himalayas.SCIENCE CHINA-EARTH SCIENCES,67(6).

Fan, Linfeng,et al."Impacts of permafrost degradation on streamflow in the northern Himalayas".SCIENCE CHINA-EARTH SCIENCES 67.6(2024).