Abstract - Using GIS for Meeting the Requirements of the National Environmental Policy Act (NEPA)

Track: Petroleum, Mining, Geosciences

Stephen Gould
GAI Consultants, Inc.
570 Beatty Road
Monroeville, PA 15146

Telephone: 412-856-6400
Fax: 412-856-4970

John Mores, Kevin Schroeder

Using GIS for Meeting the Requirements of the National Environmental Policy Act (NEPA)

Defining Issue: An Environmental Impact Statement (EIS) must be prepared under National Environmental Policy Act (NEPA) guidelines for major highway construction projects. To accomplish this task for a largescale project located in Virginia and West Virginia, ArcInfo and ArcView systems were used for data storage, manipulation, analysis, and presentation. As part of this EIS, GISbased prehistoric and historic archaeological models were developed to identify potential areas of archaeological importance. The project area is a 51mile by approximately 1-mile corridor of mountainous/karst terrain (approximately 65ÿsquare miles) along a north/south transect in Virginia and West Virginia. The project area contains land of economic, environmental, and archaeological importance and includes natural and historic resources. It includes White Sulfur Springs, a popular vacation destination, and follows the ancient Seneca Indian Trail. This natural transportation corridor was a crossroad for Union and Confederate troops during the Civil War. The EIS process requires the identification of twnety-fiveÿenvironmental resources that may be impacted by the proposed highway. Several of the more important of these resources include wetlands, surface waters, cave systems, historic structures, and historic and prehistoric archaeological sites.GIS Solution: GAI Consultants, Inc. (GAI), in cooperation with the West Virginia Division of Highways (WVDOH), developed a PCbased ArcInfo database, consisting of approximately 1.2ÿgigabytes of data, to assist the environmental scientists in preparing the EIS. The database was used to organize, store, manipulate, and analyze data to meet the goal of predicting impacts of the proposed highway on the environment. Using GIS provided increased quality control to the project by efficiently and accurately measuring areas to be impacted by the project, as well as other benefits such as being able to easily and efficiently modify the EIS analysis with changes in the project criteria.Methodology: The combining of various buffered features in ArcInfo, overlaid with the proposed highway, was used in combination with field verification to quantify potential environmental impacts. To predict the locations of prehistoric and historic archaeological sites, GAI developed sensitivity models using ArcInfo and ArcView. Criteria for the prehistoric predictive model included terrain slope, soil type and characteristics, and distances from streams. The historic sensitivity model was developed for the study area by identifying existing historic archaeological sites, historic roads, surveyed historical resources, and historically mapped sites. Buffer zones highlighting the specified criteria were developed using ArcInfo and ArcView for determining the location of potential prehistoric and historic archaeological sites.Software: The primary database for this project was developed with PC-based ArcInfo. Database querying was conducted using both ArcInfo and ArcView, and graphics and map production were conducted solely with ArcView.