3. Adjusted Population Distribution Rationale: Due to the problem of county land areas diluting the population density per square mile measure used above, a third population variable was mapped as an exclusion area. This area is identified as "adjusted population distribution" and it represents a third approach to determine the exclusion area for population. Reliability of the Data: Unlike the two previous variables, adjusted population distribution represents a somewhat subjective approach to population density. Th..- data was developed by overlaying the grid of the'United States over the U.S. Department of the Census's dot map of the population of the United States. This dot map is based upon 1970 census data. It is important to note that certain counties of the United States are large enough that 10 to 20 grid cells fit within their boundaries. By overlaying the grid cells and the dot map, substantial areas were added to the populated areas map. Although replication of the process might lead to varying results, certain rules were followed. First, any grid cell with a city of 25,000 persons or more was added. Second, if there were two towns of 10,000 persons or more, the grid cell was scored. Third, if there were combinations of a town of 10,000 or more and a number of dispersed, smaller dots, the grid cell was scored. As stated earlier, this process was subjective and was based upon visual examination of the dot map. However, it is felt that those areas covered by the "adjusted population density" variable should not be considered as sites. The important point is that the combination of the three population variables represents a rather conservative assessment of the land areas unavailable as potential sites on the basis of population. Spatial Coverage: The land area mapped as "adjusted population distribution" consists of 419 grid cells.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==