Rethinking catchment models for the future of the Great Barrier Reef

Project scope

• Declining water quality threatens the Great Barrier Reef, with nutrients and sediments from nearby catchments driving damage under climate change. Strong catchment models are needed to trace pollution sources and guide management.
• This project will apply the INCA water quality model to one or more reef catchments. Widely used overseas but not yet in this context, INCA will be adapted to Australian conditions using local data to explore nutrient and sediment dynamics.
• The project provides hands-on modelling experience and tests a process-based alternative to current reef management tools.
• Ideally a year-long project
• Available to start from February 2026.
• Flexible project mode (can be either on campus, remote or mixed modes). Desktop only work involved.
• Suitable for a student project for ENGN4200, ENGN4350, ENGN4706, ENGN4712, ENGN4718, ENGN8601, ENGN8602
• Suitable for both domestic and international students.

Project description

Declining water quality is a major threat to the Great Barrier Reef, with excess nutrients and sediments from adjacent catchments contributing to reef degradation under a changing climate. Reliable catchment-scale models are therefore essential for understanding pollutant sources, testing management strategies, and projecting future risks.

This project will apply the INCA (Integrated Catchments) process-based water-quality model to one or more Great Barrier Reef catchments. While INCA has been widely used internationally, there are no published applications for GBR catchments. The student will adapt existing INCA model setups to Australian conditions, using observed hydrological and water-quality datasets to explore nutrient and sediment dynamics. The project provides hands-on experience with environmental modelling and data analysis, and offers a unique opportunity to critically test a more mechanistic alternative to the models currently used in reef management, with direct relevance to real-world environmental decision-making.

Background

Protecting the Great Barrier Reef requires reliable modelling of how catchment processes influence nutrient and sediment loads delivered to coastal waters. In Australia, government agencies widely use the eWater SOURCE modelling framework for this purpose. However, our previous research has identified several structural and conceptual limitations in SOURCE, raising concerns about its suitability for projecting future water-quality outcomes under climate and land-use change. In contrast, INCA is a more mechanistic, process-based model that explicitly represents catchment biogeochemistry and has been successfully applied across Europe and elsewhere. Despite this, INCA has not yet been tested or published for GBR catchments. This project responds to that gap by critically examining whether a more mechanistic modelling approach can improve understanding and confidence in future water-quality projections for reef protection and management.

Project goals

The primary goal of this project is to test the feasibility and value of applying INCA to GBR catchments as an alternative or complement to existing operational models. Specific objectives include: 

1. adapting INCA to Australian datasets and catchment characteristics
2. evaluating model performance against observed streamflow and water-quality data; and
3. assessing the suitability and reliability for INCA under plausible climate change conditions. 

Through this process, the student will develop a deeper understanding of catchment-scale processes, model structure, and uncertainty under changing climate and land use. A key outcome is improved insight into whether more mechanistic models can better support long-term planning and decision-making for reef water quality. The project also aims to build transferable modelling and data skills relevant to honours, PhD, and applied environmental engineering pathways.

Deliverables

• Expected deliverables include a configured INCA model for one or more GBR catchments, a documented modelling workflow, and a quantitative evaluation of model performance and behaviour.
• The student will produce a final technical report suitable for an honours or coursework project, with potential to develop results into a conference presentation or journal paper.
• Additional outputs may include assessment of the model for climate change assessments.
• More broadly, the work contributes to improving confidence in water-quality modelling used to protect the Great Barrier Reef.

Information for applicants

Essential skills and background

• background in engineering, environmental science, or a related quantitative discipline
• be equipped with curiosity, problem-solving skills, and an interest in applying modelling to real-world environmental challenges
• be comfortable working with data and computational tools and programming languages.
• strong Python skills are essential, including experience with data processing, analysis, and basic scripting.
• be able to work independently, learn new modelling frameworks, and engage critically with scientific literature.
• be equipped with an interest in environmental systems, water quality, or climate impacts is required, along with good communication skills for documenting methods and results.

Desirable requirements

• experience or coursework in hydrology, environmental modelling, or water-quality analysis
• familiarity with numerical or process-based models, geospatial data, or time-series analysis would be an advantage.
• experience with version control (e.g. Git)
• experience in working in Linux or HPC environments, or using statistical or machine-learning methods is also beneficial.

Student takeaways

• Gain hands-on experience applying an internationally recognised, process-based water-quality model to real Great Barrier Reef catchments.
• Develop practical skills in environmental data handling, model setup and evaluation, and critical comparison of modelling approaches under future climate and land-use change.
• Exposure to policy-relevant research, insight into how models inform environmental decision-making, and opportunities to engage with an international research network working on INCA and catchment modelling. 

These skills and experiences provide a strong foundation for honours, PhD, or applied environmental and water engineering careers.

How to apply

If you are interested, please send a copy of your CV (resume) and academic transcript to the project supervisor via email.