Arancibia et al. (2026) Runoff Generation Processes and Thresholds in Agricultural Catchments of Central Chile

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Identification

• Journal: Water
• Year: 2026
• Date: 2026-08-29
• Authors: Christian Arancibia, Guillermo Barrientos, Ismael Vera-Puerto, Rafael Rubilar, Andrés Iroumé, Félix Francés
• DOI: 10.3390/w18172134

Research Groups

Not specified

Short Summary

This study investigates runoff generation thresholds in three agricultural catchments in central Chile, finding that runoff is triggered when combined precipitation and deep soil moisture exceed ~505 mm and is significantly modulated by land-use.

Objective

• To determine if nonlinear thresholds of rainfall or antecedent moisture trigger abrupt changes in the hydrological response of agricultural catchments.
• To identify the physical characteristics that determine runoff generation.

Study Configuration

• Spatial Scale: Three agricultural catchments in central Chile, ranging from 36.4 to 70.8 km².
• Temporal Scale: 2025–2026 hydrological year.

Methodology and Data

• Models used: Statistical segmented regression.
• Data sources: High-resolution observational data for precipitation and streamflow.

Main Results

• Runoff occurred in only 16 of 63 rainfall events, indicating a strong nonlinear response.
• A consistent activation threshold was identified across catchments when combined precipitation and deep soil moisture (PTOT + ASM100) exceeded ~505 mm.
• Land-use significantly influenced runoff efficiency: the most intensively agricultural catchment showed the highest specific peak discharge and a specific rainfall intensity threshold of 14.6 mm/h, driven by infiltration-excess runoff from degraded soil permeability.
• Headwater and riparian forest cover buffered rapid flows, sustained baseflow, and extended recession times.

Contributions

The study quantifies the specific subsurface control (combined precipitation and deep soil moisture) on runoff activation in central Chilean agricultural landscapes and demonstrates how land-use degradation shifts the runoff mechanism toward infiltration-excess flow.

Funding

Not specified

Citation

@article{Arancibia2026Runoff,
  author = {Arancibia, Christian and Barrientos, Guillermo and Vera-Puerto, Ismael and Rubilar, Rafael and Iroumé, Andrés and Francés, Félix},
  title = {Runoff Generation Processes and Thresholds in Agricultural Catchments of Central Chile},
  journal = {Water},
  year = {2026},
  doi = {10.3390/w18172134},
  url = {https://doi.org/10.3390/w18172134}
}