Utah Wetland Functional Classification 

Abstract / Description

The most comprehensive wetland classification system for the state of Utah is the National Wetland Inventory (NWI). While the NWI is the most complete and accessible classification system, the 366 unique wetland type identifiers in the state are often difficult to interpret and have little relevance to natural resource managers. Consequently, NWI data are often overlooked as a viable wetland data source, which often restricts opportunity for interagency cooperation as many agencies develop their own wetland GIS datasets and workflows. Many agencies would benefit from a simplification and functional reclassification of NWI data accessible to all. To address these concerns, the Utah Geological Survey reclassified the state’s wetlands to provide GIS data users a universal dataset for consistent use. The reclassification scheme was based on the hydrogeomorphic (HGM) approach, modified from recent work in Bear River Bay of Great Salt Lake, and focused largely on geomorphic, hydrodynamic, and vegetation characteristics. Of special concern within the Great Salt Lake ecosystem are impounded wetlands, which occupy over 25% of Great Salt Lake wetlands and have unique functional and management criteria as critical habitat for migratory shorebirds and waterfowl. A key aspect of this work was to refine the previous interpretation of impounded wetlands through the consideration of attributes more closely related to wetland function. Wetland landscape profiles were developed to assist in prioritizing conservation areas and integrating wetlands into watershed planning efforts. The accuracy of this crosswalk method is approximately 70% with the majority of the error attributed to erroneously mapped NWI data due to land use or land management changes.