Topic 3 - Module 1: Scale Effect and Spatial Data Aggregation

 Scale Effects on Vector Data:

In vector data, the scale at which features are represented can dramatically affect spatial analysis results. Larger scales (zoomed in) capture more detail, while smaller scales (zoomed out) generalize features. For example, analyzing counties versus ZIP codes can produce different statistical outcomes because aggregation over larger areas smooths local variability, a phenomenon known as the Modified Area Unit Problem (MAUP).

Resolution Effects on Raster Data:

Raster data are made of grid cells, and the cell size determines the spatial resolution. High-resolution rasters capture fine details but require more storage and processing power, whereas low-resolution rasters generalize information and may hide local variation. This affects analyses like slope, elevation, or population density surfaces, where resolution can change both visual and statistical results.

Gerrymandering:

Gerrymandering is the practice of drawing political district boundaries to favor a particular party or group, often resulting in irregular, non-compact districts. It can be measured using compactness metrics, such as the Polsby–Popper score, which compares the area of a district to the square of its perimeter. Scores closer to 1 indicate compact districts, while scores closer to 0 indicate elongated or bizarrely shaped districts. Other methods include analyzing the number of non-contiguous polygons and counting splits across counties.

The screenshot below shows one of the least compact districts identified using the Polsby–Popper score. Its irregular shape and elongated boundaries make it a clear example of a potential gerrymandering “offender.”

Congressional District 12: 



Comments

Post a Comment

Popular posts from this blog

Module 1- Overview of ArcGIS

Image
This week was a good intro to the program and a good start to getting used to how the system works. It will just take more practice to get used to where things are and what they do.  
Read more

Module 5: Data Points and Geocoding

  Manatee County Schools - Overview      Here is the Link to my map for this week.      The map this week is the locations of all the schools located in Manatee County, Florida. It contains information such as the coordinates, addresses, and names of the schools. Schools of all grade type are on the map. I.E elementary through college.         This weeks experience was different because we got to use Excel and partially collecting our own data from different sites. This week felt a little easier, because I have experience with Excel and I enjoy getting to use it for new things. It was nice having the labs feel a little shorter, but still learning just as much. It was easier to manage, and understand, without the potential to feel overwhelming, which I enjoyed. I didn't run into any issues in these labs, everything ran smooth.
Read more

Module 6: Georeferencing, Editing, & 3D.

Image
  This map is a georeference of three different raster images of the UWF Campus in Pensacola, Florida. The map also includes the location of a Bald Eagle nest that was found by the FWC, and the subsequent easement that was created around the nest to protect it from harm. This week's experience was pretty fun! I really enjoyed georeferencing. Matching the older pictures of the campus with the modern day map was a cool experience. Setting up control points on the map was pretty straight forward, and I felt pretty confident following the steps and indicators. I found editing the map features interesting because it was a way to add more information to show certain characteristics that need to be highlighted. Working on the 3D map was fun because it showed me a more realistic view of what the area actually looks like, which I enjoy more than the generalized maps that we have looked at previously. The following map is a georeferenced of the UWF Campus as well, on 3D scene:
Read more