This unit begins with an overview of GIS applications used in resource management, describing characteristics and functionality of these systems, and the organizations that adopted them. The body of the unit demonstrates an application of GIS to natural resource management through an example—the Big Darby Creek Project—in which the GIS provides data input, storage, output and some analytic capabilities. The project combines a GIS (ERDAS) with a nonpoint source pollution model (AGNPS) to provide a low-cost, user-friendly system and database to support land use planning and management for the basin.