Coquille Subbasin Working Atlas - p5
Population
Page 5: Population
Page 6: Vegetation and Land Cover
Page 8: Water Use and Availability
Page 9: Fish Distribution & Habitat
Population density is shown on the Population Density map as the number of persons per square mile of land area by Census block, based on the 1990 Census of Population and Housing. Census blocks are the smallest geographic units for which summary Census data are reported by the Bureau of the Census. Blocks are delineated along major roads and other physical features and typically do not coincide with watersheds, communities or other meaningful social units. Small towns and communities are often split into several blocks.
Estimating population totals
Derivation of accurate population totals within the Coquille subbasin is problematic since blocks have little relationship to either subbasins or unincorporated communities. Since blocks often overlap the boundaries of the Coquille subbasin, total population must be estimated based on the average population density for each block. For this analysis, population totals were estimated by calculating population density by block, and multiplying density by that portion of each block falling within the subbasin.
The underlying assumption of this method is that populations are evenly distributed within each block. While simple observation indicates that populations are not evenly distributed, there is no other statistical information to guide the analysis. Since most of the population within the Coquille is clustered around several small towns this only raises a question of accuracy around the town of Bandon where the extended population straddles the Southwest boundary of the Coquille subbasin. Based on this methodology, the total 1990 population within the subbasin is estimated at 16,801 persons.
The same method is used to estimate population within each of the five subdivisions. As show in Figure 10 over half of the population is in the lower portion of the subbasin within the Coquille River subdivision.
Population distribution
An estimated 92 percent of the entire population of the Coquille subbasin reside within two miles of a major stream. In an analysis of the distribution of human population relative to the Coquille River and its primary tributaries, the Census Block population density was combined with a coverage of major streams buffered within two miles on each side. Major streams include the Coquille River and the East, Middle, North and South Forks. As shown in Table 6, this pattern is fairly consistent at both subbasin and subdivision levels.
| Table 6: Total Human Population and Population Residing within Two Miles of Major Streams | |||
| Population | |||
| Subdivision | Near streams * | ||
| Subdivision | Total Persons | Persons | Percent |
| Coquille | 9,721 | 8,916 | 92% |
| East Fork Coquille | 253 | 240 | 95% |
| Middle Fork Coquille | 1,369 | 1,222 | 89% |
| North Fork Coquille | 3,521 | 3,384 | 96% |
| South Fork Coquille | 1,937 | 1,744 | 90% |
| Totals | 16,801 | 15,506 | 92% |
