Dai et al. (2025) Divergent impacts of Tibetan Plateau lakes on local and downstream water availability

Identification

• Journal: Advances in Climate Change Research
• Year: 2025
• Date: 2025-10-11
• Authors: Yufeng Dai, Deliang Chen, Lei Wang, Tinghai Ou, Xiaowen Zhang, Yang Gao, Tandong Yao
• DOI: 10.1016/j.accre.2025.09.013

Research Groups

• State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
• Department of Earth System Science, Tsinghua University, Beijing, China
• University of Chinese Academy of Sciences, Beijing, China
• Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden
• College of Information Science and Engineering, Huaqiao University, Xiamen, China
• Department of Resource Management, Tangshan Normal University, Tangshan, China

Short Summary

This study quantifies how Tibetan Plateau lake clusters regulate moisture transport and water availability through competing retention and compensation mechanisms. It finds that strong lake-effect years enhance local precipitation (retention) while weak lake-effect years promote downstream moisture export (compensation), significantly impacting dry-season water security in major Asian river basins.

Objective

• To quantify how Tibetan Plateau lake clusters regulate atmospheric moisture transport and water availability in autumn (October-November) through competing retention and compensation mechanisms, assessing their relative strengths, controlling factors, and interannual variability, particularly in extreme lake-effect years.

Study Configuration

• Spatial Scale: Tibetan Plateau (TP), focusing on lake clusters within 30.5°—32° N, 82.5°—92.5° E (southern TP), and the headwaters of the Salween, Mekong, Yangtze, and Yellow River basins.
• Temporal Scale: October to November, 1980—2019 (40 years). Annual simulations were conducted from 1 August to 30 November.

Methodology and Data

• Models used:
  • Weather Research and Forecasting (WRF) model (version 3.8) coupled with a one-dimensional (1D) lake model.
  • Eta Ferrier microphysics scheme.
  • Betts-Miller-Janjic convection scheme.
  • Noah Land Surface Model.
  • Yonsei University scheme (PBL).
  • Dudhia scheme (shortwave radiation).
  • Rapid Radiative Transfer Model (longwave radiation).
• Data sources:
  • ECMWF Reanalysis v5 (ERA5) reanalysis data (0.25° × 0.25° spatial resolution).
  • Moderate Resolution Imaging Spectroradiometer (MODIS) Land Surface Temperature product (MOD11A1 V006).
  • HydroLAKES database (v1.0) for lake boundary and depth data.
  • TP river basin boundaries (Fan et al., 2024).
  • The Third Pole High-Resolution Meteorological Forcing Dataset (TPMFD) (0.1° × 0.1° spatial resolution) for validation.

Main Results

• In strong lake-effect (LE) years, characterized by lower 500 hPa temperatures and weaker 500 hPa westerlies, intensified thermal convection and local moisture recycling (retention) increase precipitation over lakes (averaging approximately 15 mm in autumn), but reduce moisture transport and precipitation in downstream river source regions.
• In contrast, weak LE years, characterized by higher temperatures and stronger upper-level westerlies, promote efficient westerly advection and downstream moisture export (compensation), increasing precipitation in river basins (averaging approximately 5 mm).
• Over the period 1980–2019, the lake region exhibited a statistically significant decline in LE water availability (LEW, precipitation minus evaporation) of -0.18 gigatonnes (Gt) per decade (p < 0.05).
• Conversely, downstream river basins showed a statistically significant increase in LEW of +0.04 Gt per decade (p < 0.1), driven by enhanced lake evaporation and subsequent downwind precipitation.
• Extreme years highlight these dynamics: In the strong LE year 1997, the Yellow River source region faced a 0.45 Gt deficit in LEW compared to the multi-year average due to retention. In the weak LE year 1999, the Yellow River source region experienced a 0.73 Gt surplus, and the Yangtze basin a 0.75 Gt surplus, contributing to a total increase of approximately 2.2 Gt across all basins due to compensation.

Contributions

• Reveals a novel "retention—compensation binary dynamic mechanism" for Tibetan Plateau lake clusters regulating regional hydrology, advancing beyond traditional unidirectional moisture transport models.
• Establishes TP lakes as active, climate-responsive hydraulic pivots that drive competitive water redistribution across synoptic to decadal scales.
• Provides a quantitative assessment of the competing retention and compensation mechanisms, identifying them as primary physical processes governing the spatial allocation of dry-season water resources.
• Reconciles previously paradoxical trends in TP hydrology by explaining the sustained decrease in LE water availability in the lake region alongside increased supply to downstream river sources.
• Offers new insights into the regulatory role of lakes in the hydrological cycle of the TP, providing a scientific foundation for improving water resource management and dry-season water security for downstream populations.

Funding

• Youth Innovation Promotion Association of CAS (CAS2022067)
• Second Tibetan Plateau Scientific Expedition and Research Program (2024QZKK0400)
• Tsinghua University (100008001)

Citation

@article{Dai2025Divergent,
  author = {Dai, Yufeng and Chen, Deliang and Wang, Lei and Ou, Tinghai and Chen, Hong-Bin and Zhang, Xiaowen and Gao, Yang and Yao, Tandong},
  title = {Divergent impacts of Tibetan Plateau lakes on local and downstream water availability},
  journal = {Advances in Climate Change Research},
  year = {2025},
  doi = {10.1016/j.accre.2025.09.013},
  url = {https://doi.org/10.1016/j.accre.2025.09.013}
}