Issue link: http://read.dmtmag.com/i/55888
Although the compilation project was a success, lingering problems with the geologic map-creation process remained, and new problems concerning the "usability" of the Shapefiles and Access database as well as the long-term maintenance of the overall data- base structure/format were introduced. In addition, while the data were being compiled, light detection and ranging (LIDAR) data were introduced at DOGAMI. Mapping geology on 1:24,000-scale USGS topo- graphic quadrangle series basemaps was replaced by mapping on a LIDAR basemap at a more-accurate 1:8,000 scale. Problems with Map Creation The project's major difficulties included the following: polygons and lines; geologists used different methods to produce a similar result. - butes than OGDC had been built to consume. attribution wasn't efficient. and didn't meet the USGS standard. navigate for some users. Microsoft Access data into Esri ArcGIS using joins/ relates to Shapefiles. Geologic Map-Creation Standards for several years. A draft version currently is available and is recommended for use by state surveys (ngmdb. usgs.gov/Info/standards/NCGMP09). In 2006, the Federal Geographic Data Committee (FGDC) published - tion that's recommended for map production by state surveys (ncgmp.usgs.gov/ncgmpstandards). Esri also developed a Geologic Mapping Template that uses cartographic representations to effectively portray (resources.arcgis.com/gallery/file/map-templates). This template was created using the FGDC Digital as a guide. Simply stated, each geologic feature listed in the FGDC Standard is assigned a symbol and code. The representations use the codes to draw the correct symbols on a map. Figure 1. Oregon: A Geologic History (DOGAMI Interpretive Map 28, 2009) compiles rock units from OGDC into thematic groups reflecting the major events in Oregon's geologic history. This depiction is just one of many that can be made from OGDC-5 data. The DOGAMI Solution problems associated with the revised map-creation process: 1. A new geodatabase format and structure were created and implemented. 2. A new methodology was developed for geologists to streamline data creation and simplify quality analy- sis/quality control (QA/QC). 3. Cartographic representations were employed for geologic map production. File Geodatabase Structure Using the two geodatabase templates provided by USGS and Esri, DOGAMI created a custom file geo- database to allow for the detailed attributes needed database to a single file geodatabase and support FEBRUAR Y 2O12 / WWW . GEOPLA CE . COM 19