Gao et al. (2026) Evaluating the impact of climate change on water supply system reliability – a robust assessment framework using stochastic data

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-07-14
• Authors: Zitian Gao, David E. Robertson, Tze Ling Ng, Patrick Russell, Francis H. S. Chiew, John Frdelja
• DOI: 10.1016/j.jhydrol.2026.136033

Research Groups

• Commonwealth Scientific and Industrial Research Organisation (CSIRO), Environment Research Unit, Clayton, Melbourne, VIC 3168, Australia
• Water resource management consultant in Victoria, Australia
• Central Highlands Water, Ballarat, VIC 3353, Australia
• Commonwealth Scientific and Industrial Research Organisation (CSIRO), Environment Research Unit, Canberra, ACT 2601, Australia

Short Summary

This study presents a stochastic data-based framework for evaluating water supply system performance under climate change and climate variability. The framework integrates sensitivity analysis, hydrological modelling, water supply system modelling, and assessment of augmentation effects to support robust decision-making.

Objective

• Evaluate the impact of climate change on water supply system reliability using a bottom-up approach with stochastic data generation.
• Assess the effectiveness of system augmentation in improving system reliability under different climate scenarios.

Study Configuration

• Spatial Scale: Regional scale (Maryborough, Victoria, Australia)
• Temporal Scale: 1975-2021 (baseline period) and 2022-2091 (future projection)

Methodology and Data

• Models used:
  • Monthly stochastic climate data model for generating baseline and climate change impacted stochastic climate data.
  • GR4J rainfall-runoff model for simulating runoff at McCallums, Stony, and Tullaroop creeks.
  • Water supply system model (Source) developed by Central Highlands Water for simulating water supply system performance.
• Data sources:
  • Observed climate and runoff data from SILO dataset and Water Data Online portal.
  • GCM projections under Shared Socio-economic Pathway 2-4.5 (SSP2-4.5) for the study region.

Main Results

• The water supply system became less reliable under two different climate pathways: a large increase in evaporation and temperature coupled with a moderate decrease in rainfall, and a substantial decrease in rainfall.
• System restrictions and shortfalls increased rapidly over time under these pathways.
• Early augmentation was more effective than late augmentation in alleviating system restrictions.

Contributions

• This study presents a comprehensive framework for assessing water supply system reliability and augmentation effects using stochastic data generation and sensitivity analysis.
• The framework provides probabilistic insights into system performance under different climate scenarios, supporting robust decision-making.

Funding

• Not specified

Citation

@article{Gao2026Evaluating,
  author = {Gao, Zitian and Robertson, David E. and Ng, Tze Ling and Russell, Patrick and Chiew, Francis H. S. and Frdelja, John},
  title = {Evaluating the impact of climate change on water supply system reliability – a robust assessment framework using stochastic data},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.136033},
  url = {https://doi.org/10.1016/j.jhydrol.2026.136033}
}