Using GIS and a land use impact model to assess risk of soil erosion in West Gippsland
The Land Use Impact Model (LUIM) is a spatially explicit tool developed by the Department of Primary Industries Victoria, and the University of Queensland.The LUIM has an aspatial component that incorporates knowledge of relationships between landscape characteristics and land management practices and a spatial component that uses a GIS to map where these relationships exist or are likely to exist. These data are linked in a risk assessment framework by using a Bayesian belief network (BBN) within the LUIM. The soft data, sourced through workshops with experts and regional stakeholders are combined with the hard biophysical data in this network, so that uncertainties or probabilities in the data are handled in the BBN.The LUIM application described in this paper shows how it was used to inform the prioritisation of actions for a Soil Erosion Management Plan in West Gippsland. Using the LUIM, maps were produced identifying areas in the West Gippsland CMA region at risk of degradation from six soil erosion processes under current land management regimes. The risk maps were used to identify high value assets to be protected from further degradation as part of the soil erosion management plan.The LUIM fills a niche in the decision making processes for catchment management. It has the flexibility to be used at a range of scales with whatever data (hard and soft) that may be available. By combining expert opinion with hard data in a spatially explicit risk framework, priority areas can be identified and knowledge gaps highlighted. The LUIM is also adaptable to any issues that have a spatial context where natural resource assets may be threatened by degrading processes.