Sub-surface soil erosion is the biggest human-induced source of sediment entering the Great Barrier Reef and has to be addressed if Reef 2050 targets are expected to be met, but a project under the Tropical Water Quality Hub aims to find the best ways of reducing this key Reef health impact.
Revegetation programs and controlling stocking rates in erosion-prone areas is currently considered one of the most cost-effective options for reducing anthropogenic sediment levels in runoff.
The Tropical Water Quality Hub’s Project 2.1.4, led by Dr Rebecca Bartley from CSIRO, will investigate and evaluate various gully remediation options in the Burdekin catchment.
Dr Bartley and her team are measuring the cost, effectiveness and biophysical processes of these techniques in addition to evaluating their impact on the farmer’s bottom line, with the aim of changing the perception that gully and scald management does not offer a lot to the beef enterprise.
Earlier this year, the project team worked with NQ Dry Tropics and Greening Australia to select suitable Reef Trust gully sites in the Upper Burdekin, Bogie and Don River Basins. Terrain and vegetation surveys were conducted prior to installing the rainfall, runoff and water quality monitoring instruments and undertaking remediation treatments. Vegetation and land condition surveys were also completed upslope of each gully site.
“The combination of terrain scanning and water quality instrumentation will enable the measurement of the erosion, deposition and delivery (loss or export) of sediments and nutrients from these gullies under treatment and control conditions” Dr Bartley said.
“These data will be critical for evaluating the water quality improvements (or effectiveness) of the various remediation activities”.
This will provide important data that can be used in predictive modelling at both paddock and catchment scales.
The project will collect its first round of wet season monitoring data this year. This will provide important initial estimates of the success of various gully erosion remediation treatments on measured water quality. Real-time rainfall measurements at the sites and when samples are collected can be viewed here http://ermt.csiro.au/html/nesp.html.