Methods and techniques for environmental impact assessment (EIA) and development of land use management options are described. The methods and techniques have specific application in Defence estate management, and general application in other areas of land use assessment and management. The EIA methodology includes techniques for land cover and soil classification, land capability and suitability assessment. The biophysical classifications and assessment techniques are based on the application of various para and non- parametric approaches. The study area for the application of the EIA methods and techniques was the Singleton Training Area (STA) in the Hunter Valley of central New South Wales. Defence estates are required to provide a wide range of terrain and other environmental conditions to support the development of combat related tactics. The maintenance of these areas for sustainable use is fundamental in achieving both military and land use management objectives. The EIA of the STA provided a means of testing the efficiency of the methods and techniques developed in this thesis. The baseline resource inventory data used in the EIA includes land cover and vegetation maps derived from satellite digital data and soils maps derived from both conventional methods and airborne gammaradiation data. This information, together with the military land use requirements provided the basis for land capability and suitability assessment, and development of land use management options.