Published online by Cambridge University Press: 17 October 2005
Rapid assessment of land use change at scales ranging from local to global can provide timely, accurate information about land suitability, supporting infrastructure, and regulatory compliance so that developers, resource managers, planners, and decision makers can make critical decisions in the face of uncertainty. One area of concern regarding land suitability is the presence, extent, and quality of wetlands. Federal and state wetland protection legislation and local ordinances have effectively sought to reduce the amount of wetlands converted to other uses or to mitigate for unavoidable removal of wetlands. Identification and delineation of existing or potential wetlands, as well as locations that could serve as mitigation areas, is an important process in environmental planning and development. A method of identifying and delineating wetlands using the technique of rapid assessment at regional scales is presented. This method combines high-resolution remote-sensed and secondary data, including thematic maps depicting vegetation, soils, and surface hydrology in a computer-aided geographical information system. The system provides a co-occurrence analysis in which the presence of existing and historic wetlands can be mapped. Areas identified as wetlands can then be compared with detailed, on-site wetland delineations conducted by professional wetland scientists to check the accuracy of the prediction. Using various combinations of data, prediction accuracy ranged between 75% to more than 80% when compared with on-site delineation. While it is conceded that automated rapid assessment will never replace an experienced professional making a site visit, the technique demonstrates a high degree of accuracy in locating and bounding wetland systems in a cost-effective manner. Further, regional screening tools with a high degree of accuracy can substantially limit more costly and time-intensive fieldwork.