An E-Government Web Portal for Dissemination of Geotechnical Data

Abstract

The California Geological Survey (CGS) is implementing a user-friendly, GIS enabled Web portal on the Internet for the dissemination of geotechnical data to researchers, governments, and the geotechnical consulting profession. Over 20,000 geotechnical borings throughout the greater Los Angeles and San Francisco Bay regions have been acquired over the past 10 years in support of regional assessments of earthquake-induced ground failure hazard. Results of these analyses from the basis for delineating regulatory hazard zones that local government must use to improve the earthquake resistance of new construction. Borehole data include lithologic logs, index properties, and results from a variety of in situ and laboratory tests. Boring logs were acquired during decades of building and infrastructure development and were obtained from local building departments, flood control districts, highway departments and consulting firms. To navigate through the vast boring repository the CGS developed a map-oriented graphical interface, which facilitates identification of available data for particular sites of interest. Maps can be quickly generated by making a selection from either 7.5-minute USGS quadrangle or by dropdown lists of county, city, or zip code. Borehole locations can then be posted on the map view and when interactively selected the borehole metadata is displayed in a pop-up table. From the pop-up table the user can download the geotechnical data from the selected borehole. The user can also select multiple boreholes within a specific area either by selecting a quadrangle boundary, or by interactively defining a point on the map and associated radius of interest. The resulting report allows the user to view the individual records from the selection, and/or download all records into Excel format. The individual CGS database tables are represented as separate sheets in the Excel spreadsheet, and include the CGS data dictionary, and entity relationships.