VIEWING DIGITAL BOUNDARIES OF HYDROLOGIC UNITS FOR SOUTH DAKOTA USING GOOGLE EARTH

The U.S. Geological Survey completed the Watershed Boundary Dataset (WBD) for South Dakota in early 2008, and the WBD has recently been completed for the United States. The WBD subdivided 8-digit hydrologic units (subbasins) into watersheds with 10-digit codes and subwatersheds with 12-digit codes. The final product of the WBD consists of electronic drainage area and boundary data layers for use in geographic information system (GIS) software. Because of the scale and level of detail inherent in the WBD, publishing a paper map is impractical. The GIS format of the WBD is well-suited to mapping and spatial analysis, but requires the individual to own expensive GIS software. In order to make the WBD available to a wider audience of landowners, education institutions and the general public, the U.S. Geological Survey developed an internet resource page in cooperation with the Hyde County Conservation District and the South Dakota Association of Conservation Districts.

In recent years, public domain software such as Google Earth made it possible for anyone to view maps and high-resolution imagery of the earth’s surface. Converting the WBD GIS data layers to a Keyhole Markup Language (kml) file makes them available as data layers that will display in Google Earth. Users need only download a free copy of Google Earth software to a home computer or access a computer at a public library or other location that already has Google Earth installed. A kmz file (zipped kml file) of the WBD downloaded from http://sd.water.usgs.gov/projects/GoogleHuc/GoogleHUC.html may then be opened in Google Earth. The displayed map of watershed boundaries can be used to determine what water bodies may be within or immediately downstream from a watershed of interest. There are 2,411 subwatersheds within 457 watersheds across South Dakota viewable through this tool. This poster will describe how users may view the South Dakota Watershed Boundary Dataset in Google Earth, provide user tips, and highlight features of the product.