Voting Districts and Census Blocks

The map shown below depicts voting districts (green areas) in Honolulu, in the Diamondhead area, with voting district 2307 highlighted in yellow.

The map shown below depicts this same general area as Census 2000 blocks with voting district 2307 again highlighted in yellow. The upper map shows the whole district without census block subdivision and the lower map shows the district as comprised of census blocks. These maps show how a voting district can be decomposed into census blocks, the smallest geographic area for which census data are tabulated.

High School Complexes and Census Blocks

The map shown below depicts high school complex (HSC) areas (purple areas) in Honolulu, in the Diamondhead area, HSC 10813 highlighted in yellow.

The map shown below depicts this same general area as Census 2000 blocks with HSC 10813 again highlighted in yellow. The upper map shows the whole HSC without census block subdivision and the lower map shows the HSC as comprised of census blocks. These maps show how a HSC can be decomposed into census blocks, the smallest geographic area for which census data are tabulated.

How these Maps were Created

These maps are intended to be illustrative of how a geographic information system can be used to show relationships between different types of geographic areas. These maps required three map layers or themes: (1) a shape file comprised of census blocks where the corresponding dbase (dbf) file contained the census tract code, census block code, high school complex code, and voting district code, (2) a shape file comprised of voting districts, and (3) a shape file comprised of high school complex areas.

The census block layer dbf provides an equivalency file relating each census block to a voting district and high school complex area. To show an area highlighted as yellow, a query is performed on that layer/theme where the geographic area name/variable of interest is set equal to a particular code. In one query the voting district was set equal to ' 2307'. In the other query, the high school complex area code was set equal to '10813'.