Hemachandra et al. (2026) Soil-crop hydrology modelling approaches for conjunctively estimating recharge, crop demand and pumping in irrigated agriculture: a review

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-08-28
• Authors: E. M. G. P. Hemachandra, Lucy Pamela Reading, Adrian Deane Werner, P. Egodawatta
• DOI: 10.1016/j.jhydrol.2026.136308

Research Groups

• Queensland University of Technology (QUT), Brisbane, QLD 4000, Australia
• College of Science and Engineering, and the National Centre for Groundwater Research and Training, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia

Short Summary

This review examines soil-crop hydrology models that estimate regional-scale groundwater recharge, crop water use, runoff, and freshwater extraction rates to support irrigation demands. The study evaluates the reliability of these models for estimating pumping rates and their limitations in simulating conjunctive use of groundwater and surface water.

Objective

• Evaluate the key model functions and conceptual elements of existing soil-crop hydrology modelling tools applied to the coupled estimation of recharge and irrigation water supply rates.
• Assess how these tools are applied in various real-world contexts through 8 case studies.

Study Configuration

• Spatial Scale: Regional scale, with applications ranging from local to global scales.
• Temporal Scale: Daily to annual time steps, depending on the model and application.

Methodology and Data

• Models used:
  • APSIM
  • LEACHM
  • SWAP
  • CropSyst
  • HYDRUS-1D
  • SALUS
  • RZWQM2
  • DSSAT
  • STICS
  • AquaCrop
  • Daisy
  • EPIC
  • WAVES
  • MIKE SHE
  • SWAT
• Data sources: Meteorological datasets, vegetation parameters, soil hydraulic properties, irrigation and land-use practices.

Main Results

• The review found that most models evaluate the reliability of groundwater recharge and irrigation water extraction estimates depends on the representation of key hydrological and crop processes.
• Surface runoff plays a crucial role in rainfall partitioning and estimation of recharge and soil moisture content.
• Soil water movement is simulated using either tipping-bucket models or Richards' equation, with variation among models in the representation of hydraulic functions, pedotransfer functions, and macropore flow.

Contributions

• This review provides an evaluation of the key model functions and conceptual elements of existing soil-crop hydrology modelling tools applied to the coupled estimation of recharge and irrigation water supply rates.
• The study highlights the limitations of these models in simulating conjunctive use of groundwater and surface water, which is essential for capturing complex interactions between irrigation practices, soil, and aquifer dynamics.

Funding

• This research was funded by the Queensland University of Technology (QUT) and the National Centre for Groundwater Research and Training.

Citation

@article{Hemachandra2026Soilcrop,
  author = {Hemachandra, E. M. G. P. and Reading, Lucy Pamela and Werner, Adrian Deane and Egodawatta, P.},
  title = {Soil-crop hydrology modelling approaches for conjunctively estimating recharge, crop demand and pumping in irrigated agriculture: a review},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.136308},
  url = {https://doi.org/10.1016/j.jhydrol.2026.136308}
}