Research

Our Lab aims to develop new knowledge, tools and methods to improve our management of water resources under variability, change and uncertainty. Our research addresses the challenges in representing variability and change in a way that directly relates to and informs water management decisions. Much of our group’s research is applied and done in partnership with industry.

Projects

Example current projects include:

• Megadrought likelihood and its water resource impacts in Australia
• Vulnerabilities for environmental water outcomes in a variable and changing climate
• Floods in a warming climate
• Assessing water supply security in a non-stationary environment
• Lower Goulburn environmental flows study focussing on future risk: applied research

Lab capabilities

• Catchment modelling
• Water resource system simulation
• Characterisation of climate change
• Adaption and management
• Modelling interface between ecology and hydrology
• Stochastic data generation and simulation techniques
• Vulnerability assessments

Partnerships

Australian Bureau of Meteorology, Department Environment Land and Water Planning, Melbourne Water, Murray Darling Basin Authority, Goulburn-Broken Catchment Management Authority, Snowy Hydro, HydroTasmania, Water Corporation WA, Sunwater, Seqwater, WaterNSW, Dept of Natural Resources Mining and Energy (Qld), Victorian Environmental Water Holder.

Research focus

Members of our group will focus on addressing key questions on how climate variability and change impact on catchment hydrology, environmental health and the built environment.

Our approach is based on the analysis of climate data derived from observations, reanalysis products, and numerical weather prediction models, in combination with the simulation of catchment processes and environmental systems to assess vulnerabilities to a range of threats, focussing on climate change.

We aim to incorporate this improved understanding of climate risks within decision science to inform policy.

PhD students

• 
  Andrew John, Modelling change and variability in streamflow to assess environmental outcomes (Prof Rory Nathan, Dr Avril Horne, Prof Mike Stewardson)
• 
  Declan O’Shea, The changing risk of very rare to extreme floods in a warming climate (Prof Rory Nathan, Dr Conrad Wasko, Prof Ashish Sharma (UNSW))
• 
  Katayoon Bahramian, An integrated framework for short-term probabilistic flood forecasting using an event-based approach considering the uncertainty associated with natural variability (Prof Nathan, Prof Ryu, Prof Western)
• 
  Lubna Meempatta, Interactions in water use decision making by irrigators, environmental water managers and bulk providers (Prof Mike Stewardson, Dr Avril Horne, Assoc Prof Angus Webb)
• 
  Meghan Mussehl, Improving Flow Ecology Modelling Methods for Adaptive Management in Environmental Flows (Assoc Prof Angus Webb, Dr Avril Horne, Prof LeRoy Poff)
• 
  Natasha Ballis, Informing water resource analyses with palaeoclimate reconstructions (Dr Murray Peel, Prof Rory Nathan, Dr Ben Henley, Prof David Karoly)
• 
  Robert Morden, Hydrological threats to biodiversity in unregulated rivers (Dr Avril Horne, Prof Rory Nathan, Dr Nick Bond (Latrobe University))
• 
  Wen Wang, Real-time Ensemble Flood Inundation Forecasting (Prof QJ Wang & Prof Rory Nathan, Carlos Velasco & Elma Kazazic (BoM))
• 
  Yuerong Zhou, Investigation of computationally efficient schemes for modelling flood inundation (Dr Wenyan Wu, Prof QJ Wang, Prof Rory Nathan)
• Johan Visser, (UNSW), The changing risk of very rare to extreme floods (Ashish Sharma (UNSW), Lucy Marshall (UNSW), Conrad Wasko, Rory Nathan)
• Meegan Judd, (La Trobe University), Incorporating climate adaptations in environmental water management (Prof Nick Bond La Trobe and Dr Avril Horne)

Key recent publications

Environmental water in a variable and changing climate

John, Horne, Nathan, Stewardson, Webb, Wang, and Poff (2020) Climate change and freshwater ecology: Hydrological and ecological methods of comparable complexity are needed to predict risk. WIREs Clim Change. 2020;e692. https://doi.org/10.1002/wcc.692

John, Nathan, Horne, Stewardson, Webb; (2020) How to incorporate climate change into modelling environmental water outcomes: a review. Journal of Water and Climate Change, 1 June 2020; 11 (2): 327–340. doi: https://doi.org/10.2166/wcc.2020.263

Moore, Rutherfurd, Peel, & Horne. 'Sub-Prime' Water, Low-Security Entitlements and Policy Challenges in Over-Allocated River Basins: the Case of the Murray–Darling Basin. Environmental Management 66, 202–217 (2020). https://doi.org/10.1007/s00267-020-01303-7

Horne, Nathan, Bond, Poff, Webb (2019) Modeling Flow-Ecology Responses in the Anthropocene: Challenges for Sustainable Riverine Management, BioScience, Volume 69, Issue 10, October 2019, Pages 789–799, https://doi.org/10.1093/biosci/biz087

Wang, J., Nathan, R., & Horne, A. (2018). Assessing the Impact of Climate Change on Environmental Outcomes in the Context of Natural Climate Variability. Journal of Water Resources Planning and Management, 144(12). https://doi.org/10.1061/(ASCE)WR.1943-5452.0001008

Wang, J., Nathan, R., Horne, A., Peel, M. C., Wei, Y., & Langford, J. (2017). Evaluating four downscaling methods for assessment of climate change impact on ecological indicators. Environmental Modelling and Software, 96, 68–82. https://doi.org/10.1016/j.envsoft.2017.06.016

Wang, J., Horne, A., Nathan, R., Peel, M., & Neave, I. (2018). Vulnerability of Ecological Condition to the Sequencing of Wet and Dry Spells Prior to and during the Murray-Darling Basin Millennium Drought. Journal of Water Resources Planning and Management, 144(8). https://doi.org/10.1061/(ASCE)WR.1943-5452.0000963

Floods in a warming climate

Wasko, C., Nathan, R., & Peel, M. C. (2020). Trends in Global Flood and Streamflow Timing Based on Local Water Year. Water Resources Research, 56(8), 1–12. https://doi.org/10.1029/2020wr027233

Wasko, C., Nathan, R., & Peel, M. (2020). Changes in Antecedent Soil Moisture Modulate Flood Seasonality in a Changing Climate. Water Resources Research, 56(3). Retrieved from https://doi.org/10.1029/2019WR026300

Wasko, C., & Nathan, R. (2019). The local dependency of precipitation on historical changes in temperature. Climatic Change, 156(1–2), 105–120.

Wasko, C., & Nathan, R. (2019). Influence of changes in rainfall and soil moisture on trends in flooding. Journal of Hydrology, 575 (November 2018), 432–441. https://doi.org/10.1016/j.jhydrol.2019.05.054

Gillen, J., Costelloe, J. F., Allen, K. J., Fallon, F. J., Peel, M. C., Stewardson, M., & Nathan, R. (2021). Can riparian eucalypts be used for hydroclimatic reconstruction ? The case for Eucalyptus coolabah to define paleo-flood events. Journal of Arid Environments, 184 (September 2020), 104301. https://doi.org/10.1016/j.jaridenv.2020.104301

Visser, J. B., Wasko, C., Sharma, A., & Nathan, R. (2020). Resolving Inconsistencies in Extreme Precipitation ‐ Temperature Sensitivities Geophysical Research Letters. Geophysical Research Letters, 47(18). https://doi.org/10.1029/2020GL089723

Wasko, C., Sharma, A., & Lettenmaier, D.P. (2019). Increases in temperature do not translate to increased flooding. Nature Communications, 10, 5676. https://doi.org/10.1038/s41467-019-13612-5

Hettiarachchi, S., Wasko, C. & Sharma, A. (2019). Can antecedent moisture conditions modulate the increase in flood risk due to climate change in urban catchments? Journal of Hydrology, 571, 11–20. https://doi.org/10.1016/j.jhydrol.2019.01.039

Sharma, A., Wasko, C., & Lettenmaier, D.P. (2018). If Precipitation Extremes Are Increasing, Why Aren't Floods? Water Resources Research, 54, 8545–8551. https://doi.org/10.1029/2018WR023749

Water supply security in a nonstationary environment

Henley, B. J., Peel, M., Nathan, R., King, A. D., Ukkola, A. M., Karoly, D., & Tan, K. S. (2019). Amplification of risks to water supply at 1.5°C and 2°C in drying climates: a case study for Melbourne, Australia. Environmental Research Letters, 14(8), 84028. https://doi.org/10.1088/1748-9326/ab26ef

Mehran A, AghaKouchak A, Nakhjiri N, Stewardson MJ, Peel MC, Phillips TJ, Yoshihide W & Ravalico JK, 2017. Compounding Impacts of Human-Induced Water Stress and Climate Change on Water Availability. Scientific Reports, 7, 6282.

Nathan, McMahon, Peel and Horne (2019) Assessing the degree of hydrologic stress due to climate change, Climatic Change. https://link.springer.com/article/10.1007/s10584-019-02497-4

O’Donnell, Garrick and Horne (2019) Reallocation through irrigation modernization: The 'once-in-a-hundred-year' opportunity of the North-South Pipeline, Australia, Water Security, 6.

Hydrology to inform water resource decisions under change and uncertainty

Barria P, Peel MC, Walsh KJE & Garreaud R, 2017. Analysis of within and between-GCM uncertainties of runoff projections in Mediterranean-like catchment. Journal of Southern Hemisphere Earth Systems Science, 67(3), 181–213.

Fowler K, Peel M, Western A & Zhang L, 2018. Improved rainfall-runoff calibration for drying climate: choice of objective function. Water Resources Research, 54, 3392–3408.

Fowler K, Coxon G, Freer J, Peel MC, Wagener T, Western A, Woods R & Zhang L, 2018. Simulating runoff under changing climatic conditions: a framework for model improvement. Water Resources Research, 54, 9812–9832.

Fowler K, Knoben W, Peel MC, Peterson T, Ryu D, Saft M, Seo K-W & Western A, 2020. Many commonly used rainfall-runoff models lack long, slow dynamics: implications for runoff projections. Water Resources Research, 56: e2019WR025286.

Guo, D., Zheng, F., Gupta, H., & Maier, H. R. (2020). On the Robustness of Conceptual Rainfall‐Runoff Models to Calibration and Evaluation Data Set Splits Selection: A Large Sample Investigation. Water Resources Research, 56(3), e2019WR026752.

Guo, D., Johnson, F., & Marshall, L. (2018). Assessing the potential robustness of conceptual rainfall-runoff models under a changing climate. Water Resources Research, 54(7), 5030–5049. doi: https://doi.org/10.1029/2018WR022636

Guo, D., Westra, S., & Maier, H. R. (2018). An inverse approach to perturb historical rainfall data for scenario-neutral climate impact studies. Journal of Hydrology, 556, 877-890. doi: https://doi.org/10.1016/j.jhydrol.2016.03.025

Guo, D., Westra, S., & Maier, H. R. (2017). Use of a scenario-neutral approach to identify the key hydro-meteorological attributes that impact runoff from a natural catchment. Journal of Hydrology, 554, 317–330. doi: https://doi.org/10.1016/j.jhydrol.2017.09.021

Guo, D., Westra, S., & Maier, H. R. (2017). Impact of evapotranspiration process representation on runoff projections from conceptual rainfall-runoff models. Water Resources Research, 53. doi: 10.1002/2016WR019627

Improving environmental water management

Horne, Webb, Stewardson, Richter, Acreman (Eds) (2017) Water for the Environment: from Policy and Science to Implementation and Management. Elsevier, Cambridge MA.

Arthington, Bhaduri, Bunn, Jackson, Tharme, Tickner, Young, Acreman, Baker, Capon, Horne, Kendy, McClain, Poff, Richter, Ward (2018) The Brisbane Declaration and Global action agenda on environmental flows (2018), Frontiers Ecological Science.

Horne A, O’Donnell E, Loch A, Adamson D, Hart B and Freebairn J (2018) Environmental water efficiency: Maximizing benefits and minimizing costs of environmental water use and management. Wiley Interdisciplinary Reviews: Water

Kaur, S., Horne, A., Nathan, R., Szemis, J. ., Gibson, L., Costa, A. M., Webb, J.A., Stewardson, M.A. (2019). Examining trade-offs in piggybacking flow events while making environmental release decisions in a river system. Journal of Water Resources Planning and Management, 145(6). Retrieved from https://doi.org/10.1061/(ASCE)WR.1943-5452.0001048

Horne, A. C., Szemis, J. M., Webb, J. A., Kaur, S., Stewardson, M. J., Bond, N., & Nathan, R. (2018). Informing Environmental Water Management Decisions: Using Conditional Probability Networks to Address the Information Needs of Planning and Implementation Cycles. Environmental Management, 61(3), 347–357. https://doi.org/10.1007/s00267-017-0874-8

Horne, A. C., Kaur, S., Szemis, J. M., Costa, A. M., Nathan, R., Webb, J. A., … Boland, N. (2018). Active Management of Environmental Water to Improve Ecological Outcomes. Journal of Water Resources Planning and Management, 144(12). https://doi.org/10.1061/(ASCE)WR.1943-5452.0000991

Kaur, S., Horne, A., Stewardson, M., Nathan, R., Costa, A. M., Szemis, J. ., & Webb, J. A. (2017). Challenges in determining frequency of high flow spells for varying thresholds in environmental flows programs. Journal Ecohydraulics, 2, 28–37. https://doi.org/10.1080/24705357.2016.1276418

Horne, A., Kaur, S., Szemis, J., Costa, A., Webb, J. A., Nathan, R., … Boland, N. (2017). Using optimization to develop a “designer” environmental flow regime. Environmental Modelling & Software, 88, 188–199. https://doi.org/10.1016/j.envsoft.2016.11.020