Chapter 2.2.1 - A Landscape-Level Wetland Functional Assessment Tool: Building a Framework for Watershed-Based Assessments in the United States

Abstract

Given increasing interest in watershed planning and management and improved information on the functions of wetlands, the U.S. Fish and Wildlife Service's National Wetlands Inventory Program (NWI) considered ways of expanding the use of its data in landscape-level wetland functional assessments. To accomplish this, the NWI developed a set of hydrogeomorphic-type descriptors (landscape position, landform, water flow path, and waterbody type) that could be added to its digital database to facilitate and improve its use for producing watershed-based functional assessments of wetlands. These new descriptors were added to NWI databases to create what have been called “NWI+ data” to prepare watershed-based or statewide wetland characterizations and preliminary assessments of wetland functions. This paper describes the new descriptors and the correlations between enhanced NWI wetland characteristics and functions as well as presents examples of their application and discusses use of the data by various agencies.