Soil and land constraint assessment for urban and regional planning

Abstract

A new approach to land capability assessment, termed soil and land constraint assessment, has been developed and carried out over an area of 60,000 km2 along the NSW coast and in the Hawkesbury-Nepean Catchment in eastern NSW. The system allows for the generation of soil and land constraint maps that portray in detail the physical potential of the land to support a range of land uses, including standard residential development, agriculture and domestic wastewater disposal. It involves a semi-quantitative analysis of soil-landscape constraints such as erosion, flood and mass movement hazards, and includes a broad indication of potential costs necessary to overcome these constraints. The system has been extensively field tested and was found to be reliable in approximately 80% of sites, with a tendency to give conservative results (i.e. indicate higher constraints than actually present). It is recommended for broadscale planning only and not site-specific development control. Twenty of the 34 standard land use zones used in Local Environmental Plans in NSW are effectively covered. The results can be readily interpreted by land use planners and land managers and should contribute to environmentally sustainable land use decision making. The process could be adapted to apply to similar natural resource datasets in other Australian states.