The U.S. Fish and Wildlife Service (Service) is the principal Federal agency that provides information to the public on the extent and status of the Nation's wetlands. The National Wetlands Inventory has extensive mapping expertise and knowledge involving wetland identification and classification, image interpretation, and digital data capabilities. Reflecting this expertise, the NWI has been regularly asked to provide resource mapping guidance and requested to map riparian areas of the western United States.
With growing interest in riparian habitats in the western U.S., the Service undertook early riparian mapping projects for several agencies in Arizona in the early 1990s. Additional projects were conducted for the National Park Service in Nevada, and the Bureau of Land Management in Wyoming. Each project included a variety of definitions, classifications, and mapping conventions. The Service was regularly asked to map riparian areas in the western United States, but lacked a standard definition and conventions to guide the mapping.
In 1997, the National Wetlands Inventory made a commitment to assemble a committee of habitat and cartographic specialists to develop the Service’s riparian definition and mapping conventions. In 2000, western Service Regions began implementation of the system.
Riparian areas are plant communities contiguous to and affected by surface and subsurface hydrologic features of perennial or intermittent lotic and lentic water bodies (rivers, streams, lakes, or drainage ways). Riparian areas are usually transitional between wetland and upland. Riparian areas have one or both of the following characteristics:
Digital riparian data can be viewed using the Wetlands Mapper. Riparian data is also available for download for the continental United States in Geodatabase or Shapefile format. Though riparian digital map data can stand alone, it is recommended that this data be used in conjunction with the associated wetlands data. This will provide a “complete picture” of the ecological systems that have been mapped.