Needs and Requirements: Key Reasons for GIS Model Development for the North Carolina Department of Transportation
The merged NEPA/404 permit process allows for preliminary design and environmental data to be gathered and analyzed for all NCDOT projects. These data are then used to select the best alternative for construction of a given project designated as an Environmental Assessment (EA) or Environmental Impact Statement (EIS) level undertaking.
This increase of environmental consideration at the front end of the NEPA process is designed to foster better decision making regarding selection of a given undertaking's build alternative. Of all of the environmental constraints, only archaeological resources are not carried forward to the same level of identification and evaluation as community impacts, wetland delineation, and air/noise issues etc. The use of GIS technology for predicting and quantifying potential archaeological impacts is viewed as a way to streamline the identification of archaeological resources early in the NEPA process.
The reasons for the lag in the identification and evaluation of archaeological sites within a transportation project usually revolve around several issues. Cost, securing right of entry agreements, and project schedule; as well as background information on known sites within an undertaking's Area of Potential Effect, are all important in the selection of a project build alternative. In fact, the Section 106 regulations acknowledge this issue by allowing for a phased identification process to satisfy the regulations using these background reports and/or archaeological probabilities to establish context based on information from known sites near a given undertaking.
While containing key information, standard background reports do not provide relative probabilities for containing archaeological sites, either by significance or cultural affiliation, for given corridors/alternatives. Nor do they easily provide a mechanism for testing the broad premises contained in these reports. For example, archaeological background information may indicate that Early Archaic sites tend to cluster on broad ridges, and appear to be associated with a given soil type. Without some way of generating the actual location and dimensions of all landforms containing the referenced soil type, it is difficult to rank the liklihood of proposed alternatives for containing this site type in a meaningful way.
This is where the GIS archaeological predictive model approach will prove invaluable to the North Carolina Department of Transportation. This approach will allow summary tables quantifying an undertaking's probable archaeological impacts to be available early in the project planning process. Just as important will be the dynamic nature of the information. The GIS approach will allow for ready adaptability to changes that occur throughout the life of a given project, including the addition of new corridors and or alternatives for study. When this occurs, by using GIS, a clear understanding of the new alternative's archaeological potential can be generated quickly without the need to revise or create addenda to an existing report.
Aside from the NEPA driven rational for applying GIS technology, there is another benefit to those managing the project. With a clear and concise (albeit initially untested) model of archaeological sensitivity for all alternatives contained within project corridors, a better understanding of the scope, cost and timeframe associated with the field effort emerges. This will allow more realistic project schedules to be generated.
Another key benefit of this approach involves the coordination of state and federal agencies responsible for compliance with NEPA and Section 106. In order to make the GIS approach work, the massive amount of archaeological site data contained at the Office of State Archaeology (OSA) must be available for review and analysis in digital format. These data are currently maintained primarily on paper and microfiche. This project will create and maintain a modern digital site database to use for the model development process. By using project funding to accomplish this task, the regulatory agency gets digitized archaeological site information to use for future planning purposes with a minimum of expenses for the OSA. Ultimately, the OSA, through creation of a web based environment to access the archaeological site data, will be able to significantly streamline the process and quickly produce the volume of hard copy information currently generated by those using the archaeological site files. It will also be able to incorporate new site information in a more timely and efficient manner.
Other benefits will include making the archeological site probability information available to planning organizations state-wide via a web-based environment. Once the initial information is created in a digitized format and refined through field efforts, certified local governments, cities, county agencies, and regional planning organizations will be able to better plan their undertakings at a reduced cost in both time and money.
