@article{fdi:010093329,
  title = {{R}ecent ground thermo-hydrological changes in a southern {T}ibetan endorheic catchment and implications for lake level changes},
  author = {{M}artin, {L}.{C}.{P}. and {W}estermann, {S}. and {M}agni, {M}. and {B}run, {F}anny and {F}iddes, {J}. and {L}ei, {Y}. and {K}raaijenbrink, {P}. and {M}athys, {T}. and {L}anger, {M}. and {A}llen, {S}. and {I}mmerzeel, {W}.{W}.},
  editor = {},
  language = {{ENG}},
  abstract = {{C}limate change modifies the water and energy fluxes between the atmosphere and the surface in mountainous regions such as the {Q}inghai-{T}ibet {P}lateau ({QTP}), which has shown substantial hydrological changes over the last decades, including rapid lake level variations. {T}he ground across the {QTP} hosts either permafrost or is seasonally frozen, and, in this environment, the ground thermal regime influences liquid water availability, evaporation and runoff. {C}onsequently, climate-induced changes in the ground thermal regime may contribute to variations in lake levels, but the validity of this hypothesis has yet to be established. {T}his study focuses on the cryo-hydrology of the catchment of {L}ake {P}aiku (southern {T}ibet) for the 1980-2019 period. {W}e process {ERA}5 data with downscaling and clustering tools ({T}opo{SCALE}, {T}opo{SUB}) to account for the spatial variability of the climate in our forcing data ({F}iddes and {G}ruber, 2012, 2014). {W}e use a distributed setup of the {C}ryo{G}rid community model (version 1.0) to quantify thermo-hydrological changes in the ground during this period. {F}orcing data and simulation outputs are validated with data from a weather station, surface temperature loggers and observations of lake level variations. {O}ur lake budget reconstruction shows that the main water input to the lake is direct precipitation (310 mm yr-1), followed by glacier runoff (280 mm yr-1) and land runoff (180 mm yr-1). {H}owever, altogether these components do not offset evaporation (860 mm yr-1). {O}ur results show that both seasonal frozen ground and permafrost have warmed (0.17°{C} per decade 2 m deep), increasing the availability of liquid water in the ground and the duration of seasonal thaw. {C}orrelations with annual values suggest that both phenomena promote evaporation and runoff. {Y}et, ground warming drives a strong increase in subsurface runoff so that the runoff/(evaporation + runoff) ratio increases over time. {T}his increase likely contributed to stabilizing the lake level decrease after 2010. {S}ummer evaporation is an important energy sink, and we find active-layer deepening only where evaporation is limited. {T}he presence of permafrost is found to promote evaporation at the expense of runoff, consistently with recent studies suggesting that a shallow active layer maintains higher water contents close to the surface. {H}owever, this relationship seems to be climate dependent, and we show that a colder and wetter climate produces the opposite effect. {A}lthough the present study was performed at the catchment scale, we suggest that this ambivalent influence of permafrost may help to understand the contrasting lake level variations observed between the south and north of the {QTP}, opening new perspectives for future investigations.},
  keywords = {{TIBET} ; {QINGHAI} {PLATEAU} ; {PAIKU} {LAC}},
  booktitle = {},
  journal = {{H}ydrology and {E}arth {S}ystem {S}ciences},
  volume = {27},
  numero = {24},
  pages = {4409--4436},
  ISSN = {1607-7938},
  year = {2023},
  DOI = {10.5194/hess-27-4409-2023},
  URL = {https://www.documentation.ird.fr/hor/fdi:010093329},
}