INTERACTIVE GEOLOGIC TRANSPORTATION MAPS: A MODEL FOR THEIR CREATION, IMPLEMENTATION, AND MAINTENANCE

Knowledge of surface and subsurface geology is fundamental to the planning and development of multi-modal transportation systems, which in Rhode Island incorporate linked highway, rail, air, and water transportation networks. Toward this end, we have compiled a GIS database consisting of important geologic, cartographic, environmental, and cultural data along a transportation corridor in Rhode Island. These data are presented as twenty-seven spatially defined themes that can be overlaid on-screen or in printed format to quickly show the geographic distribution of the diverse types of data. Such capability permits the quick determination of the spatial relationship of transportation corridors to geologic setting, environmentally sensitive areas, areas of cultural importance, and other relevant features. This exercise expedites site evaluation and planning.

Geologic data include bedrock geology, outcrops, surficial materials, soils, topographic and orthophoto base maps, and location of ground-water-wells and boreholes. Subsurface data associated with the site-specific wells and boreholes are an integral component of the database including land-surface elevation, depth to water table, depth to bedrock, and material properties, all of which are invaluable for transportation planning. Users of this database can quickly assess the distribution and quality of existing subsurface data, readily identifying locations where supplementary data are needed. Thus, the need for expensive new borings that duplicate previous effort can be minimized. Currently this interactive database is distributed on a CD-rom, which includes a simplified viewer.

Our project serves as a model for 21st Century compilation of geologic and geotechnical information for transportation corridors on a local to statewide basis. The database is structured to easily incorporate new data as it is acquired, thus providing condensed, easily accessed information of the type essential to transportation planning. In addition to transportation applications, the spatial data also is of interest to a broader audience, including state agencies dealing with environmental management and planning issues, town planners, conservation and environmental groups, and concerned citizens.