Work

Distributed and semi-distributed hydrological modelling for catchments draining to the Great Barrier Reef coastline

Year: 2025

Type: article

Abstract: The Great Barrier Reef (GBR) is a renowned natural wonder of the world. Estimation of flows entering the GBR from eastward-draining rivers is crucial to quantifying the associated pollutant load threatening the coral reef’s well-being. A distributed hydrological model – Grid-to-Grid (G2G) – has been set up at a spatial-temporal resolution of 0.01° (~1km) and 1 hour to simulate these flows. A semi-distributed hydrological model – Short-term Water Information Forecasting Tool (SWIFT) – has been set up for 9 catchments at 19 streamflow gauging locations to generate 7-day Streamflow Forecasts operationally. In this research, the performance of both models has been evaluated at common locations for both models. The Nash-Sutcliffe Efficiency (NSE), Mean Absolute Error (MAE) and Relative Bias (RBias) performance metrics, along with visual inspection of hydrographs, are used to compare model performance. Performances of both models vary from site to site and are broadly comparable, although the SWIFT model's performance is slightly better than G2G because it is specifically calibrated to each gauged catchment. In contrast, G2G is configured as a single area-wide model, making use of all gauged catchments. It is capable of generating outputs for any grid-cell across the model domain, either at gauged or ungauged locations. Both catchment-specific and area-wide modelling approaches have their strengths and limitations and can be used to serve specific modelling purposes.

Source: Hydrology research

DOI: 10.2166/nh.2025.156