APPLYING ARCSCAN IN GEOLOGIC MAPPING TO CONVERT HAND-DRAWN GEOLOGIC CONTACTS

When necessary to convert hand-drawn lines representing geologic contacts and other information to GIS-based data, application of ArcScan provides a time-saving alternative to heads-up digitizing or digitizing paper maps. This particular effort focused on the surficial geology of the Effingham 7.5-minute quadrangle in northeastern Kansas, an area with a high density of geologic contacts. Specific software utilized was ArcGIS for Desktop 10.1, ArcScan 10.1 ArcGIS Spatial Analyst, which was used in conjunction with a Colortrac SmartLF Gx+ T42 scanner. Here ArcScan was employed to convert hand-drawn geologic contacts to a feature class for use in geologic mapping. After preliminary cleanup of the scanned map in Adobe Photoshop, the mapped quadrangle was rectified and automatic vectorization used to create a set of contact lines. After elimination of all topological errors, the lines were converted to polygons and attributed for use in the map product. Hardcopies of the map are being printed on HP Designjet Z6100ps printers. Surficial geologic data were field-derived as part of multi-year, USGS STATEMAP-funded project.