Information

Impact of vegetation cover and slope on runoff, erosion and water quality for field plots on a range of soil and spoil materials on central Queensland coal mines - Curragh

Level 1 General description

Purpose:

The purpose of this study was to determine under natural rainfall:

  • Runoff and sediment loss for a range of soil and spoil materials; and
  • The impact of pasture cover on runoff, sediment loss and salt transport from 3 slope gradients.

Methods (brief)

Three slope gradients (approximately 10, 20 and 30%) were prepared for each site. A depth of 20-30 cm of soil at Curragh and Goonyella/Riverside and 10cm at Oaky Creek was laid on the top of the spoil and ripped at 1 m intervals across each slope. Pasture and tree treatments were imposed on soil and spoil material, while on the 20% slope, single soil and spoil plots were left bare as a comparison with the vegetated treatments. Sediment and runoff were measured from 14 bounded plots, each 0.01 ha (20 m by 5 m) in size.

Key findings (brief)

The greatest window of erosion risk was before vegetation establishment where a large proportion of surface areas were exposed to the erosion forces of rain and runoff. This study showed there was little difference in soil erosion rates between slope gradients once a dense sward of buffel grass established on soil plots. Vegetation growth also reduced soluble salt concentrations at the surface of spoil material and reduced the risk of salt movement on and off site. Where spoils were crusted, poor seedling establishment and vegetation growth as a result of unacceptable large runoff and erosion rates occurred throughout the study sites.

Location

The experimental sites were located at 3 mine site in central Queensland. This site was located at Curragh (23.29oS, 148.58oE).

Related studies

The same investigation was carried out at Goonyella and Oaky Creek

 

 

Level 2, level 3, level 4, level 5