Zambrano et al. (2026) Agricultural land-use composition modulates hydroclimatic coupling of cropland water use efficiency under prolonged aridification: sub-watershed evidence from Chile’s megadrought

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-10-07
• Authors: Francisco Zambrano, Francisco Fernández, María Molinos‐Senante
• DOI: 10.1016/j.jhydrol.2026.136584

Research Groups

• Facultad de Medicina Veterinaría y Agronomía, Universidad de Las Américas (Chile)
• Facultad de Agronomía y Sistemas Naturales, Pontificia Universidad Católica de Chile (Chile)
• Instituto para El Desarrollo Sustentable, Pontificia Universidad Católica de Chile (Chile)
• Institute of Sustainable Processes, Universidad de Valladolid (Spain)

Short Summary

This study investigates the impact of prolonged aridification on cropland water-use efficiency in 127 Chilean agricultural sub-watersheds from 2001 to 2020. The results show that WUE responses are spatially heterogeneous and influenced by crop system composition, irrigation infrastructure prevalence, and latitudinal gradient.

Objective

• Investigate the effect of prolonged aridification on cropland water-use efficiency in Chilean agricultural sub-watersheds

Study Configuration

• Spatial Scale: 127 Chilean agricultural sub-watersheds
• Temporal Scale: 2001 to 2020, a period spanning an unprecedented megadrought

Methodology and Data

• Models used: Standardized Precipitation-Evapotranspiration Index (SPEI) and Standardized Precipitation Index (SPI)
• Data sources: Satellite data, observation data, and reanalysis data

Main Results

• WUE responses are spatially heterogeneous: arid and semi-arid sub-watersheds show predominantly negative ΔWUE, while irrigated Mediterranean sub-watersheds show positive ΔWUE
• Negative long-term trends and structural breaks are concentrated in the 30–35◦S band
• Precipitation deficit indices dominate cross-sectional WUE sensitivity: SPEI and SPI show practically equivalent explanatory power (two one-sided tests p<0.001, 90% CI [−0.004, +0.003])
• Crop system composition is associated with WUE drought sensitivity through two contrasting patterns:
  • Annual-crop prevalence is robustly and negatively associated with drought sensitivity across all latitude-control specifications (spatial error model β range: −0.341 to −0.591, p<0.01)
  • Irrigation infrastructure prevalence shows a positive association with WUE-drought coupling that is not distinguishable from the latitudinal aridity gradient

Contributions

• This study provides new insights into the impact of prolonged aridification on cropland water-use efficiency in Chilean agricultural sub-watersheds, highlighting the importance of crop system composition and irrigation infrastructure prevalence.
• The findings are consistent with crop-portfolio flexibility and suggest that WUE responses are spatially heterogeneous.

Funding

• This research was funded by [project name], [program name], and [reference code]

Citation

@article{Zambrano2026Agricultural,
  author = {Zambrano, Francisco and Fernández, Francisco and Molinos‐Senante, María},
  title = {Agricultural land-use composition modulates hydroclimatic coupling of cropland water use efficiency under prolonged aridification: sub-watershed evidence from Chile’s megadrought},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.136584},
  url = {https://doi.org/10.1016/j.jhydrol.2026.136584}
}