Model Library

Great Barrier Reef Dynamic Sednet (GBR Dynamic Sednet)

Model name: Great Barrier Reef Dynamic Sednet (GBR Dynamic Sednet)

Developed by: Queensland Government Department of Science (DES) (Last update: 2022)

Model type: Distributed, daily time-step, process-based, hydrological and water quality, catchment model

History: The model is built on eWater Source – Australia's National Hydrological modelling platform.

Computational requirements: Windows XP or later, minimum 512 MB of RAM, 1 GB recommended, minimum 2 GB of free hard disk space, minimum 800 x 600 or higher-resolution display with 256 colours.

Software requirements: Microsoft Data Access Components 2.6 or later, Microsoft Internet Explorer 5.01 or later, .net framework 1.1 redistributable or later; GIS: optional

Link to download model: Not open-source. Contact opendata@agency.qld.gov.au for any information.

Capabilities and Limitations:

Capabilities

  • It models nutrient and sediment generation from various land uses, including grazing, conservation, forestry, sugarcane, cropping, and urban environments. It accounts for waterway processes like hillslope, gully, streambank erosion, channel remobilization, and sediment/nutrient deposition in floodplains and storage areas (Baird et al., 2021);
  • It supports representation of different land management levels for agricultural land uses and their impact on load generation (Baird et al., 2021);
  • It retains nutrient enrichment ratios for comparability with previous water quality models (McCloskey et al., 2021);
  • Independent delivery ratios can be set for particulates, avoiding assumptions of complete connectivity to streams (McCloskey et al., 2021).

Limitations

  • Not open-source;
  • It simulates only two sediment types: fine and coarse sand (McCloskey et al., 2021);
  • It represents sediment sources as hillslope, gully, and stream (streambank and channel) but does not explicitly differentiate between surface and subsurface sources (McCloskey et al., 2021);
  • It does not account for surface losses caused by aeolian processes or landslips (McCloskey et al., 2021);
  • It relies on RUSLE to estimate erosion and sediment loads (McCloskey et al., 2021);
  • While independent delivery ratios can be applied, the model's compartmentalization into only fine and coarse sediment classes limits representation of the full range of particle sizes, such as clay fractions (McCloskey et al., 2021).

Model Inputs and Outputs:

Inputs

DEM, Soil data, LULC, Meteorological data, Hydrological data, Water quality data

Outputs

GBR Dynamic SedNet simulates flows, loads of nutrients and total sediment (fine and coarse) yields on a daily timestep.

Example:

Reference

McCloskey, G. L., Baheerathan, R., Dougall, C., Ellis, R., Bennett, F. R., Waters, D., Darr, S., Fentie, B., Hateley, L. R., & Askildsen, M. (2021). Modelled estimates of fine sediment and particulate nutrients delivered from the Great Barrier Reef catchments. Marine Pollution Bulletin, 165, 112163. https://doi.org/10.1016/j.marpolbul.2021.112163

Objective

The aim of this paper is to present the modelled estimates of fine sediment and particulate nutrients being delivered to the GBR lagoon from 35 basins, and the sources and sinks of each in these regions.

Other resources: All of the data used in (and generated by) the catchment models, the models themselves and the software are stored in the Science Knowledge and Information Portal (SKIP). SKIP is accessible to all users once registered with the Queensland Government Open Data portal.