HARNESSING THE POWER OF RELATIONAL DATABASES FOR MANAGING SUBSURFACE GEOTECHNICAL AND GEOLOGIC DATA

Knowledge of surface and subsurface geology is fundamental to the planning and development of transportation systems, as well as other engineering land uses. Through dynamic coupling of readily available areal GIS coverages and subsurface borehole data stored in a relational database, we have created a spatially referenced digital catalog of borehole data for 2 pilot areas: a transportation corridor near the U. of RI and an urban zone centered around Providence, RI. The borehole database is populated with data derived from RI DOT geotechnical reports and with supplemental data from the US Geological Survey ground-water site inventory system, and local storm-water and sewer projects. Most of these data were previously maintained in paper format, making historical or inter-project data comparisons virtually impossible. Unification of these data in a single relational database yields two primary benefits: 1) historical data are readily accessible for review and can therefore be easily incorporated into the planning stages of new projects and 2) sophisticated analysis of the region becomes possible with access to data from multiple projects with both spatial and temporal coverage. In addition to engineering applications, the spatial data are also 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.

Geologic data include bedrock geology, surface outcrops, unconsolidated materials, soil types, topographic and orthophotographic base maps, and location of ground-water-wells and boreholes. Subsurface geologic and hydrologic data associated with the site-specific wells and boreholes include land-surface elevation, depth to water table, depth to bedrock, and material properties including presence of fill, high and low blow-count zones, and organic sediment. The digital catalog is distributed on a CD-ROM that includes ArcView project files and an Access relational database. The borehole data are also accessible through the Internet, with retrieval access for all users and data entry privileges for registered users (http://geo.uri.edu/borehole/index.asp). Ongoing development of the database will incorporate detailed subsurface lithology and geochemical data.