Sarker et al. (2026) Geographic complexity in Queensland irrigation water pricing: Spatial and temporal dynamics revealed by generalized additive models

Identification

• Journal: Agricultural Water Management
• Year: 2026
• Date: 2026-07-28
• Authors: Jaba Rani Sarker, John C. Rolfe, Delwar Akbar
• DOI: 10.1016/j.agwat.2026.110659

Research Groups

• School of Business and Law, Central Queensland University
• Department of Local Government, Water and Volunteers (DLGWV)
• Queensland Competition Authority (QCA)

Short Summary

This study examines the spatial and temporal dynamics of irrigation water pricing across 16 Queensland water supply schemes over eleven years (2015–2025) using generalized additive models. The results reveal significant non-linear spatial and temporal price patterns, with prices increasing by 115%–164% above 2015 baseline levels through to 2024.

Objective

• Investigate the spatial and temporal dynamics of irrigation water pricing across Queensland's diverse schemes.
• Examine the factors driving observed price differentials between schemes and sectors.
• Identify systematic geographic pricing gradients and their relationship to scheme location, crop composition, and climate variability.

Study Configuration

• Spatial Scale: 16 Queensland regional water delivery schemes spanning from the Mareeba-Dimbula in the north to the Border Rivers and Condamine-Balonne in the south.
• Temporal Scale: Eleven years (2015–2025).

Methodology and Data

• Models used: Generalized Additive Models (GAMs), fixed effects panel model, and cross-sectional log-linear regression.
• Data sources: Permanent water entitlement trading reports published by DLGWV.

Main Results

• Significant non-linear spatial and temporal price patterns were revealed using GAMs, explaining 40% of price variation.
• Prices increased by 115%–164% above 2015 baseline levels through to 2024.
• A structural break was identified in 2019, with prices rising sharply after that year.

Contributions

• This study provides a comprehensive spatial, temporal, and economic characterization of Queensland's water pricing dynamics.
• The findings have direct implications for water pricing policy, market regulation, and cost recovery frameworks in Queensland and other jurisdictions with geographically segmented irrigation markets.

Funding

• Not specified.

Citation

@article{Sarker2026Geographic,
  author = {Sarker, Jaba Rani and Rolfe, John C. and Akbar, Delwar},
  title = {Geographic complexity in Queensland irrigation water pricing: Spatial and temporal dynamics revealed by generalized additive models},
  journal = {Agricultural Water Management},
  year = {2026},
  doi = {10.1016/j.agwat.2026.110659},
  url = {https://doi.org/10.1016/j.agwat.2026.110659}
}