Decision-Support Tools: Bayesian Modeling

In the Water Planning Tools project, we have been exploring the use of Bayesian modeling for water planning, particularly in the use of network modeling for social and economic impact and risk assessment. Bayesian modelling approaches are increasingly being used as decision support tools in many areas of natural resources management to:

determine the risks to aquatic ecosystems from multiple threats, such as flow changes, excessive nutrients degradation of instream habitat, riparian vegetation and pest fauna and flora
integrate qualitative and quantitative information across a range of disciplines and stakeholders
prioritise management activities, within an adaptive management context, to achieve the best outcomes when resources are limited
link investments to resource condition outcomes
inform risk management strategies through scenario analysis.

Due to the potential of Bayesian modelling for addressing risk and uncertainty in modeling and decision-support frameworks, the 14th National Water Commission's Waterlines Report reviews its application for use in the determination and management of environmental flow allocations. Prepared by Water Science Pty Ltd and researchers from the Australian National University, the report found significant opportunities for Bayesian modelling as a foundation for the adaptive management approaches to reinstating environmental flow requirements for rivers and wetlands. Specifically, the report found the potential of Bayesian modelling to improve current water planning tools and approaches by:

providing simple, visual representation of conceptual models and causal links that are easily communicated
documenting the rationale behind environmental flow recommendations for future use
validating the science underpinning individual flow recommendations, and testing the effectiveness of an implemented flow regime
facilitating adaptive management by using the data collected in monitoring programs to iteratively improve the models used to estimate the flow requirements for different parts of the ecosystem
predicting and demonstrating the risks associated with not providing the agreed environmental flow regime
providing potential for stakeholders representing different interests to use a single tool in scenario analysis and decision-making.

Download the National Water Commission's Executive Summary on Bayesian modelling for risk-based environmental water allocation, or the Waterlines full report.