Cui et al. (2026) Runoff thresholds, runoff generation mechanisms, and catchment characteristics: a global synthesis

Identification

• Journal: Hydrology and earth system sciences
• Year: 2026
• Date: 2026-08-20
• Authors: Zhen Cui, Fuqiang Tian
• DOI: 10.5194/hess-30-5281-2026

Research Groups

• Department of Hydraulic Engineering, State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China
• Key Laboratory of Hydrosphere Sciences of the Ministry of Water Resources, Tsinghua University, Beijing 100084, China

Short Summary

This study synthesizes reported storm-runoff thresholds from 138 experimental catchments worldwide, linking threshold indicators, dominant runoff generation mechanisms, wetness-dependent mechanism transitions, and soil–geology–hydrogeology contexts within a common analytical framework.

Objective

• Investigate the representation of threshold-related runoff mechanisms across climatic wetness settings.
• Examine how dominant runoff mechanisms change within catchments as event wetness increases.

Study Configuration

• Spatial Scale: Global distribution of 138 experimental catchments worldwide.
• Temporal Scale: Event-scale observations, including rainfall and runoff time series, hydrograph or hysteresis analyses, soil moisture or groundwater dynamics, tracers or isotopes.

Methodology and Data

• Models used: None mentioned in the paper.
• Data sources: Peer-reviewed studies reporting rainfall–runoff nonlinearity, abrupt stormflow responses, or runoff threshold behavior from experimental catchments worldwide.

Main Results

• Subsurface- and saturation-related mechanisms (SSF and SOF) are most frequently reported across all reviewed catchments.
• Hydrological-state indicators (e.g., antecedent precipitation index, soil water content, groundwater level) and composite rainfall–state indicators are used more often than rainfall-only metrics to identify threshold-like behavior.
• Wetness-dependent mechanism shifts from surface-dominated responses toward subsurface- or groundwater-influenced responses are reported more frequently than in the reverse direction.

Contributions

• This study provides a global synthesis linking reported threshold indicators, runoff generation mechanisms, and catchment structural controls within a common framework.
• The findings support a connectivity-based framework where rainfall forcing interacts with catchment state and structural constraints to activate or connect runoff pathways.

Funding

• Not mentioned in the paper.

Citation

@article{Cui2026Runoff,
  author = {Cui, Zhen and Tian, Fuqiang},
  title = {Runoff thresholds, runoff generation mechanisms, and catchment characteristics: a global synthesis},
  journal = {Hydrology and earth system sciences},
  year = {2026},
  doi = {10.5194/hess-30-5281-2026},
  url = {https://doi.org/10.5194/hess-30-5281-2026}
}