GIS 5935 Module 6

This week we have been working exploring the effects of scale and resolution on spatial data. We first completed an exercise that compared vectors at different resolutions. We found that resolution had a great impact on the quality and completeness of data. The lower the resolution of the data used the less detail and less completeness is achieved in data. Higher resolution data results in more detail of vector features and are typically more complete. We compared the lengths of vector data at various resolutions to determine if there were differences in vectors derived at different resolutions. We also compared rasters at different resolutions to determine if there were any differences at varying resolutions. We used rasters to determine slopes and used the values derived from slopes to make comparisons  of resolutions between 2 and 50 meters. The values for slope that were derived varied by over six degrees between 2 and 50 meters. It is evident that when data derived from rasters can be significantly impacted by resolution. 

The second part of this weeks assignment had to do with gerrymandering. The New Times describes gerrymandering as drawing congressional district maps specifically to "tilt political power in favor of one party" (Wines 2019). Geographically gerrymandering creates odd shaped congressional districts that were drawn a particular way to benefit a particular political party. In some occasions congressional districts will have odd shapes or may be composed of a series of land islands that somehow contain political or societal conditions that are favorable to a political party. Because of the odd shapes that are produced we can deduce where gerrymandering is occurring using a mathematical formula that produces a score which involves the area and the perimeter of a congressional district. The score derived in the described formula is the Polsby-Popper score.  The Polsby-Popper score measures compactness of a district. The less compact a district is determined to be the more likely that it has a jagged exterior boundary that has likely been drawn to politically benefit a certain party. 

Below is a screenshot of Congressional District 12 which in my analysis had the lowest Polsby-Popper Score. The odd shape of this district's perimeter is evident. 

Works Cited:

Wines, M. (2019, June 27) What is gerrymandering and how does it work. The New York Times. https://www.nytimes.com/2019/06/27/us/what-is-gerrymandering.html