Risk mapping in the Condamine River catchment basin

Abstract

Erosion and Salinity are two of the most significant environmental problems impacting on agricultural lands in Australia. Currently 48000 hectares of Queensland are seriously affected by salinity, and an estimated 3100000 hectares of Queensland are also likely to be affected by the year 2050 (Gordon, I. 2002). When this is combined with approximately 20 to 60 tonnes of top soil per hectare being lost from cropping areas on an annual basis (Carey, B, Harris, P. 2001), it has become apparent that action needs to be taken. Through instigating efficient land management practices we must aim to prevent the formation of saline soils and water ways and at the same time limit the loss of top-soil through erosion. A key tool in the management of salinity and erosion is the process of 'risk mapping'. This tool has already been successfully used for salinity and erosion risk mapping as well as in other areas such as Fire Risk Mapping (Rural Fire Service, Queensland) and Forest Health Risk Mapping (Department of Agriculture, C'wealth). Risk mapping uses input datasets which reflect environmental (both natural and human) attributes such as vegetation, soils, terrain, waterways, geology and rainfall. These data sets can be manipulated to show environmental indicators for various issues. It will be a key objective of this project to create salinity and erosion risk maps for the Condamine River Catchment Area using environmental data-sets in a 'weighted overlay' process.