Chen et al. (2025) Emerging Patterns of Changes in Intra‐Annual Variability of Streamflow

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Geophysical Research Letters
• Year: 2025
• Date: 2025-11-19
• Authors: Xinyu Chen, Liguang Jiang
• DOI: 10.1029/2025gl118724

Research Groups

[Information not available in the abstract.]

Short Summary

This study presents the first large-scale analysis of spatial patterns in long-term trends of intra-annual streamflow variability from 1970 to 2022 across 12,311 streamflow stations. It found that approximately 23% of stations exhibit significant trends, with increasing variability dominating in tropical regions due to declining low flows, and decreasing variability prevailing in cold regions due to rising low flows, indicating widespread non-precipitation-led flow regime changes.

Objective

• To analyze the spatial patterns in long-term trends of intra-annual streamflow variability from 1970 to 2022 across free-flowing and non-free-flowing rivers in diverse climate zones.

Study Configuration

• Spatial Scale: Large-scale analysis covering 12,311 streamflow stations globally, across diverse climate zones including tropical, cold, and arid/semi-arid transition regions.
• Temporal Scale: Long-term trends analyzed over a period of 53 years, from 1970 to 2022.

Methodology and Data

• Models used: Not explicitly mentioned in the abstract.
• Data sources: Observational data from 12,311 streamflow stations; analysis of precipitation variability.

Main Results

• Approximately 23% of the analyzed streamflow stations exhibit significant trends in intra-annual variability, with roughly 11% showing increasing variability and 12% showing decreasing variability.
• Increasing streamflow variability is predominant in tropical regions, primarily driven by declining low flows.
• Decreasing streamflow variability is prevalent in cold regions, mainly attributed to rising low flows.
• In arid and semi-arid transition zones, changes in variability are strongly linked to overall reductions in streamflow.
• Non-free-flowing rivers show a higher proportion of decreasing variability compared to free-flowing rivers.
• Consistency between precipitation variability and streamflow variability is observed only in tropical regions, suggesting that flow regime changes in other regions are largely not driven by precipitation variability.

Contributions

• Presents the first large-scale observational analysis of spatial patterns in long-term trends of intra-annual streamflow variability across a vast network of 12,311 stations.
• Identifies distinct spatial patterns of streamflow variability trends linked to specific climate zones (tropical, cold, arid/semi-arid) and underlying hydrological drivers (e.g., changes in low flows).
• Highlights the differential impact of human interventions by comparing trends in free-flowing versus non-free-flowing rivers.
• Reveals that widespread changes in streamflow regimes are often decoupled from precipitation variability, particularly outside tropical regions, suggesting other dominant factors.

Funding

[Information not available in the abstract.]

Citation

@article{Chen2025Emerging,
  author = {Chen, Xinyu and Jiang, Liguang},
  title = {Emerging Patterns of Changes in Intra‐Annual Variability of Streamflow},
  journal = {Geophysical Research Letters},
  year = {2025},
  doi = {10.1029/2025gl118724},
  url = {https://doi.org/10.1029/2025gl118724}
}