EGU23-6834, updated on 25 Feb 2023
https://doi.org/10.5194/egusphere-egu23-6834
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Lake evaporation and its effects on basin evapotranspiration and lake water storage on the inner Tibetan Plateau

Liuming Wang1,2, Junxiao Wang3, and Xingong Li4
Liuming Wang et al.
  • 1School of Geography and Ocean Science, Nanjing University, Nanjing 210023, China (dg1927033@smail.nju.edu.cn)
  • 2Department of Ecohydrology and Biogeochemistry, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany (liuming.wang@igb-berlin.de)
  • 3School of Public Administration, Nanjing University of Finance & Economics, Nanjing, 210023, China (wangjunxiao@nufe.edu.cn)
  • 4Department of Geography and Atmospheric Science, University of Kansas, Lawrence, 66045, USA (lixi@ku.edu)

Lake evaporation (EW) is an important component of both basin evapotranspiration (ETB) and lake water balance for lake-basins on the inner Tibetan Plateau (IB), and it greatly influences lake water storage change (ΔSW). However, the effects of EW on ETB and ΔSW at lake-basin scale have never been reported for most basins on the IB. In this study, the EW of 117 large lakes (area > 50 km2) in 95 closed lake-basins (area > 1000 km2) were estimated, and its effects on ETB and ΔSW over 2001-2018 were examined using several newly derived diagnostic equations from the aspects of EW amount, rate, trend slope and inter-annual variability. During the study period, mean annual EW rate and total EW amount for the lakes are 994.25 ± 20.48 mm, and 24.83 ± 0.52 km3 respectively. The significant increasing trend (0.29 ± 0.04 km3/a) in annual EW amount is mainly caused by the increase (224.65 km2/a) in lake area (82.13%), and the increase (2.12 ± 1.28 mm/a) in EW rate is responsible for the rest (17.87%). EW accounts for 23.16% ± 4.94% of the ETB (107.24 ± 21.90 km3) for the 95 basins, and its impact has increased significantly (0.20% ± 0.09%/a) over the period. The increasing trends of EW rate and lake area ratio (0.06%, P < 0.05) contributed 14.49% and 52.69% to the increase trend in ETB (0.85 mm/a), and their variances contributed 1.60% ~ 4.79% and 1.64% ~ 6.50% to ETB variance (155.44 ± 107.97 mm2), respectively. The contribution of EW, quasi lake inflow (RL, 23.48 km3), and lake surface precipitation (PW, 9.18 km3) to mean ΔSW (7.82 km3) are -43.02%, 40.84% and 15.96%, respectively. And the increasing trends of the three components (EW, RL and PW) account for -58.02%, 29.59% and 12.39% of the decrease trend in annual ΔSW (-0.81 × 10 km3/a, P > 0.05), respectively. Basin RL, derived based on lake water balance, is significantly correlated with two independent land surface net precipitation estimates (0.57 < R < 0.86), and basin lake area ratio is a good indicator of basin EW and lake inflow in the IB.

How to cite: Wang, L., Wang, J., and Li, X.: Lake evaporation and its effects on basin evapotranspiration and lake water storage on the inner Tibetan Plateau, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-6834, https://doi.org/10.5194/egusphere-egu23-6834, 2023.