Highway project development often requires environmental analyses of several alternative corridors and alignments. These analyses invariably include assessing the impact of projects on wetlands. However, common wetland-identification sources such as National Wetland Inventory (NWI) maps, U.S.G.S. topographical maps, and Soil Conservation Service country soil surveys do not always provide the information necessary for evaluating and comparing potential impacts of alternative highway corridors or alignments during the project development process. Although federal agencies have agreed on a methodology for identifying and delineating wetlands (Federal Interagency Committee on Wetland Delineation, Federal Manual for Identifying and Delineating Jurisdictional Wetlands, 1989--an interagency cooperative publication, U.S. Army Corps of Engineers, U.S. Environmental Protection Agency, U.S. Fish and Wildlife Service, and U.S.D.A. Soil Conservation Service, Washington, DC), extensive field investigations to identify, classify, and locate wetlands in sufficient detail within project corridors and alignments are costly and time consuming. Many environmental issues, including wetlands, must be analyzed to reduce the number of alternative corridors or alignments under consideration and to eventually justify requests for the necessary regulatory permits on the final alignment.

There are no readily available methods for efficiently and effectively identifying, classifying, and locating wetlands within corridors and alignments beyond the detail and accuracy of NWI maps. Consequently, there is a need to assess the application of remote sensing technologies to the various stages of project development. An evaluation of technologies and geographical information systems in combination with other existing information resources will be required.

The objectives of this project are as follows: (1) define methodologies suitable for cost effective and timely identification, classification, and location of wetlands required to support decisions throughout the highway project development process; and (2) evaluate technologies in terms of cost, procedures, personnel, practicality, application, and accuracy for applying the methodologies.

The applicability of each methodology and associated technologies will depend on the accuracy required at various stages of project development, the cost, and the statistical significance and confidence of the necessary measurements. Application of the methods and technologies also will be based on consideration of their suitability and applicability to various geographic regions, wetland sizes, and classification detail within the Fish and Wildlife Service system (Classification of Wetlands and Deepwater Habitats of the United States, Cowardin et al., Washington, DC, December 1979).

These project objectives will be accomplished in two phases and will require at least the following tasks.

Phase I: (1) Information Search--Conduct a comprehensive literature search to locate, assemble, and analyze applicable information. Identify and analyze ongoing related research and applications. Sources for this information will include, but are not limited to, computerized research information services, universities, state and federal transportation and natural resource agencies, environmental and engineering consultants, and industries, such as utility companies. (2) Interview Plan--Based on the results of Task 1, identify and select application managers and research project leaders for follow-up interviews. A list of suitable questions will need to be developed for the interviews to obtain details on the various methodologies and technologies. Within 3 months of contract initiation, a summary report of Tasks 1 and 2 will be submitted for NCHRP approval and authorization to proceed with subsequent tasks. (3) Interviews--Perform follow-up interviews. (4) Phase I Final Report--Synthesize and evaluate the information acquired under the previous tasks, fully describing the recommended methodologies and technologies, and develop the Task 5 field-testing program.

Phase II: (5) Field Tests--Test the applicability and accuracy of the recommended technologies to implement the various methods identified in Phase I. Field tests will be verified by comparing the results of field tests to actual detailed wetland identifications and delineations using both the Federal Manual for Identifying and Delineating Jurisdictional Wetlands and the Fish and Wildlife Service classification system. Each technology will be evaluated to satisfy the terms of Objective 2. (6) Preliminary Outline--Submit a detailed outline of the Phase II final report for approval by the NCHRP. (7) Phase II Final Report--Fully document the Phase II effort. Based on the results of Task 5, modify and refine the recommendations of Task 4, as appropriate; and provide information that will allow users to determine the suitability of the methodologies and their associated technologies for implementation within various stages of the highway-development process. The information shall include the cost and performance characteristics that were evaluated in Task 5, presented in the form of suitable graphics, matrices, illustrations, and tables. Sufficient detail on the technical procedures must be provided so that the procedures can be duplicated.

Status: The project has been completed. Although the original intent of the project (to identify and assess remote sensing technologies for wetland identification, classification, and delineation) was not technically feasible, the research agency provided information on wetland planning within the transportation planning and development process.

Product Availability: The agency final report will not be published but is available for loan or purchase on request to the NCHRP.