DATA MANAGEMENT IN PENNSYLVANIA'S STATEMAP PROGRAM

Pennsylvania's STATEMAP program often employs contractors from outside of the geological survey to conduct the geological mapping. Their data and resulting draft maps are then submitted to the PA Geological Survey for final publication. As the program expanded, our GIS staff spent too much of its map production time deciphering the data formats used by various contractors. To streamline the process a digital data collection system was developed that standardizes the data format and assists the contractors in preparing their preliminary map.

The centerpiece of the system is a user-friendly form within an Access database that facilitates data entry for each field station. To standardize data input, the form employs a variety of pick lists which the user can customize to control the options that will be displayed in the form. Each scientist is free to enter their measurements in the format that they used to collect it. Built-in routines, run by the user, extract and format the data into 6 standardized export tables: station data, lithology data, planar measurements, linear measurements, contact data, and sample data. An ArcMap project file distributed with the Access database directly reads data from these export tables and displays them as fully symbolized event themes. After data collection is complete, this ArcMap project is used as the template to develop the geodatabase containing the feature classes for the digital geologic map

To further standardize the digital map production process, a set of requirements for the point, line, and polygon feature classes have been developed. Also distributed with the database is a constantly expanding ArcMap style that predefines the symbology for commonly used structural symbols and lines as well as the fills for geologic polygons. This is especially important because the symbol set currently available in ArcMap lacks adequate symbols for metamorphic foliations. Finally, we provide guidelines for metadata, and for legend material and explanatory text that accompanies the map.

Contractors are not required to provide the geologic polygon features. Instead, they provide geologic contacts and a point feature containing the polygon attributes. Topology is preserved because smoothing and other processing of the lines is completed before the polygons are built.