IMPROVED INPUTS FOR PREDICTION OF REGIONAL-SCALE SOIL EROSION POTENTIAL FOR QUEENSLAND

Soil erosion is a major form of land degradation in Queensland, which impacts on both on-site costs as well as offsite infrastructure, conservation assets and adjacent farmlands. For some time, there has been an active program of experimental research on runoff and erosion processes at a farm scale. However, for catchment scale planning and use of natural resources, a broad-scale assessment of the potential for soil erosion is required to predict the spatial impacts of land-use and prioritise investments in solutions. A spatial version of the Universal Soil Loss Equation (USLE) has been developed for this purpose in Queensland. The USLE factors rainfall erosivity, soil erodibility, slope and length of slope have been derived from a range of spatial estimation approaches using the best available information for Queensland. When combined with a cover index, these factors will produce a spatial map of the inherent hazard to hillslope soil erosion based on the physical features of landscapes, land management and climate. The development of the soil erosion assessment map can then provide a framework for government and catchment community groups to focus their activities in areas where the risks of potential soil erosion are greatest.