Lake Rim GIS  
Layer Reference Information 

    For each layer, the list below gives the source of information, the date of the information, and the source scale. Spatial datasets may have been derived from various sources (with or without good documentation regarding their creation and processing), by digitizing published or unpublished maps, from datasets with locational information in the form of the congressional coordinate system (which may have been plotted and digitized, or converted directly to latitude and longitude, using computer software), or by using global positioning system (GPS) equipment.

     A final note: the maps that you compose using a GIS are very different from the paper maps that you may have used in the past: they are hybrids of maps derived from many different sources and constructed with widely varying standards of accuracy. A published map from an established agency - such as the Indiana Geological Survey or the U.S. Geological Survey - has been subjected to thorough review and cross-checking and is produced in accordance with well-established standards. Many of the layers in this GIS are derived from such sources. But other layers within this GIS are derived from spatial datasets that are still under construction and that have not been thoroughly reviewed and checked, nor subjected to established quality-control procedures. Nevertheless, such incomplete and unchecked datasets have been included in this GIS because it may be many years until they have been upgraded to the standards required for conventional publication, and we assume that many users may wish to have access to such data during the interim. LET THE USER BEWARE. It is especially important that the user pay attention to the source scale: a feature plotted on a map that was originally compiled at a scale of 1:250,000 may not appear to overlay that exact same feature plotted on a map compiled at a scale of 1:24,000. Usually - although not always - the location from the latter map would be considered more accurate.

Map coordinates are in the Universal Transverse Mercator (UTM) coordinate system, zone 16. This is the coordinate system used by the Indiana Geological Survey. In the case of those layers for which projection information was complete, the NAD27 datum is used. However, some of the layers that were acquired from other sources did not include information on the datum; for those layers the datum is unknown and may be either NAD27 or NAD83. In the Lake Rim area, this could create a 200 meter displacement of features in a north-to-south direction.

     For contact information of persons who provided the datasets please visit the link
About Lake Rim GIS.