One of my mapping projects for this summer involved creating a hypothetical redistricting map of what the New Hampshire House of Representatives might look like if it used single-member districts. Currently, the chamber uses multi-member and floterial districts, as it contains four hundred members. The box below allows you to zoom in and see the map in closer detail. Each district has a number in order to help viewers differentiate between each. Beneath is a discussion of how I made the map and some final thoughts.
How I Made The Map
Creating this map was a process that took up most of my summer. Given the pandemic, I had more free time than usual, but I still had a number of things to do as part of my graduate schoolwork. In this section, I describe the process of creating it.
- I began by downloading a shapefile from the U.S. Census Bureau which shows the various census blocks within the state. These blocks formed the component parts of each district, with the shapefile serving as my basemap. The specific shapefile I used contained population data, which was crucial for the next phases of the process.
- Next, I loaded the shapefile into QGIS. As my personal preference was to minimize splitting towns, I also loaded a shapefile from the Census Bureau containing town outlines.
- Within QGIS, I then loaded a plugin called the Statto Software Redistricter. This plugin allows you to create redistricting maps from a shapefile which contains population data. Unfortunately, the plugin no longer appears available to download.
- From there, it was a two-month process of clicking away at the various blocks in order to get districts that were fairly equal in population. The plugin contains features which helped ease this process, including the ability to select entire census tracts at once, and the ability to select multiple blocks. Due to my own preference to minimize town splits, and the size of some blocks, most districts are not exactly at the target number of 3,291 people. I managed to get most within ±50 people of the desired number, however. This, of course, was by far the most tedious step.
- Once I finished assigning all the blocks, I ran QGIS's "dissolve" feature, which produced a shapefile containing just the district lines. I then uploaded this shapefile into the Mapbox website.
- Given that this shapefile contained numbers for each district, Mapbox enabled me to identify any enclaves, which I then went back and corrected to the best of my ability. (Some of them may have been too small for me to notice, so you may come across a couple remaining. These generally would have no more than a minor impact on the population). In theory, the plugin should have been able to do this, but I was unable to do so.
- Following this process, I re-uploaded the shapefile into Mapbox, producing the completed map.
Final Thoughts
In closing, I think one thing this map shows is that the usage of multi-member districts for the NH HOR is clearly warranted, barring a reduction in the number of members. This many single-member districts would be far too unwieldy and produce absurdly small districts, such as District #239 in Manchester, which is only around eleven blocks in length. Although, on the other hand, I guess campaigning wouldn't be too difficult. My intention, however, was not to expose the House as an absurd body, but more of an intellectual and cartographic exercise to satisfy my own curiosity. I hope you enjoy looking at the map, and feel free to comment below if you have any thoughts or questions.
