GIS-ing Flood Data Continued from page 35 tools to explore them in conjunction with other relevant GIS data. Departments could store these studies in a relational database management system, thus making it accessible through the county network. The county could also provide this information to the public through Web GIS and eliminate the labor associated with the previous process. To achieve these goals, the county's Floodplain Management and GIS sections teamed up to complete the conversion process and create an informative and useful flood GIS layer. Conversion Process The ArcGIS Desktop environment was chosen for the conversion because of its advanced tools, existing database environment, and low learning curve. The conversion process included the following steps: 1. Search paper flood studies for the base information that will help locate any data that should be added. 2. Locate the study site. Because studies are basically survey drawings, they have range, township, and section information that can be used to track down the site. Survey notes can be used to create the boundary if no parcel or subdivision lines are available. 3. Check the validity of the study. New information might be available for the same area from The image above is a scanned unaligned study area that needs to be georeferenced. The image on the left shows an image of the same area that has been georeferenced. It has been rotated, stretched, and aligned. 36 ArcUser Fall 2010 www.esri.com