WETLANDS ASSESSMENT AND IDENTIFICATION USING REMOTE SENSING AND GIS DATA WITHIN A KNOWLEDGE-BASED CLASSIFIER

The accurate identification of wetlands is essential to many environmental, hydrologic, and engineering geology studies. Wetlands are biologically diverse, ecologically and economically valuable, and heavily regulated. Wetlands occupy a transitional zone between terrestrial and aquatic habitats, and exhibit features of each to varying degrees. They differ widely in character, even in a local region, due to differences in soils, topography, hydrology, water chemistry, vegetation, and other factors. Contributing to the confusion on what constitutes a wetland is the fact that different agencies have jurisdiction over wetland areas and different definitions delimiting them. Because wetlands can vary so significantly within a given type, no universally recognized wetland definition exists. This study presents a knowledge-based classification system protocol designed to delineate wetlands in the Toledo region of northwest Ohio. An expert-based classification system is used to address the problems in the enforcement of wetland regulations by providing a rapid, legally defensible preliminary wetland identification system. The protocol was designed to match the EPA and U.S. Army Corps of Engineers requirements for jurisdictional wetlands (areas possessing hydrophytes, hydric soils, and hydrology). It integrates multi-temporal Landsat 7 data with SSURGO-based soils information and USGS digital elevation models to provide a wetland identification tool that can be used by non-experts. The classification protocol identifies and delineates five varieties of wetlands in the region: coastal, prairie, riverine, forested wetlands as well as open water habitats.