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Data Transfer and Uncompression Information

Hydrology and Transportation Data

The hydrology and transportation data are 1:100,000-scale data. The hydrology data were modified, to display either the tributaries of the Upper Mississippi River System (UMRS) or land/water features within the floodplain. If you require these data in their original format, contact the EROS Data Center.

The hydrology and transportation data are available for the full length of the UMRS. The UMRS is defined as the navigatable portions of the Mississippi River, from Cairo, Illinois to Minneapolis, Minnesota and includes the full length of the Illinois River.

The data are stored as compressed ArcView shape files. All data have been projected to UTM Zone 15, north American datum 1927 (NAD27), and the Clark 1866 ellipsoid.

Transfer Option

   ArcView Shape Files: The ArcView shape files containd double precision data that was compressed using the software program WinZip. These files are stored as PC/NT format data, if you want to transfer them to a UNIX computer the shape files are transferred as binary format data. Any legend (.avl) or metadata (.txt) files stored with the data should be transfered using ASCII protocols, so a DOS to UNIX file conversion will be performed.

To restore the data:

1. Download and store the compressed file(s) on a personal computer (PC) or NT workstation.
2. Uncompress the data by activating the .exe file.
   Use a Windows 3.1 File Manager or a Windows 95, 98, 2000's Windows Explorer, or NT Explorer program to locate the executeable (.exe file) on your hard drive. Activate the uncompression routine by double clicking on the file name. If you need to add any additional information like identifying an output directory, the uncompression program will prompt you for this information.
3. The uncompressed files are ready to use. If you're accessing these data using ArcView GIS software, use the Add Theme function to locate and add the shape file to a view window.

   Metadata: Metadata for the land cover/use and aquatic areas data sets are stored as ASCII text files. The files are viewable by clicking on the metadata graphic. To download the metadata file, either hold the computer's mouse over the metadata graphic and press the mouse's right-hand mouse button or use which ever option your web browser contains for saving files.