Aryal et al. (2025) Spatio-temporal heterogeneities in hydrologic dynamics across the Asian Water Tower

Identification

• Journal: Journal of Hydrology
• Year: 2025
• Date: 2025-07-19
• Authors: Saugat Aryal, Yadu Pokhrel
• DOI: 10.1016/j.jhydrol.2025.133951

Research Groups

• Department of Civil and Environmental Engineering, Michigan State University, USA

Short Summary

This study employs high-resolution hydrological-hydrodynamic modeling to analyze hydrologic changes across the Asian Water Tower (AWT) from 1979 to 2018, revealing significant spatio-temporal heterogeneity in flood risks and water storage components.

Objective

• To evaluate multi-decadal spatio-temporal heterogeneities in hydrologic dynamics (river discharge, water storage, flood regimes, and terrestrial water storage) across the basins of the Asian Water Tower.

Study Configuration

• Spatial Scale: The entire Asian Water Tower (AWT) region, categorized into Western, Central, Eastern, and Southeastern basins.
• Temporal Scale: Multi-decadal period from 1979 to 2018.

Methodology and Data

• Models used: High-resolution hydrological-hydrodynamic modeling.
• Data sources: GRACE (Gravity Recovery and Climate Experiment) for terrestrial water storage (TWS) and remotely sensed data.

Main Results

• Western Basins (Amu Darya, Tarim): Observed an increase in flood occurrence by up to ~60%, with Snow Water Equivalent (SWE) contributing up to ~41% to TWS.
• Central Basins (Ganges): Transitioning toward increased water scarcity, with subsurface storage contributing up to ~79% to TWS.
• Eastern Basins (Yangtze, Yellow River): Dominance of subsurface storage (~78% for the Yangtze and ~83% for the Yellow River), with the Yangtze also showing a notable river storage contribution of ~21%.
• Southeastern Basins (Mekong, Irrawaddy, Salween): Exhibited complex, temporally varying patterns that do not fit simple regional categorizations.

Contributions

• The research provides a comprehensive, high-resolution analysis of the entire AWT, filling a critical knowledge gap caused by the scarcity of in-situ data in high-altitude regions. It demonstrates that the complex interplay of surface and subsurface processes necessitates basin-specific water resource management and climate adaptation strategies rather than a one-size-fits-all regional approach.

Funding

• Not specified in the provided text.

Citation

@article{Aryal2025Spatiotemporal,
  author = {Aryal, Saugat and Pokhrel, Yadu},
  title = {Spatio-temporal heterogeneities in hydrologic dynamics across the Asian Water Tower},
  journal = {Journal of Hydrology},
  year = {2025},
  doi = {10.1016/j.jhydrol.2025.133951},
  url = {https://doi.org/10.1016/j.jhydrol.2025.133951}
}