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Partisan advantage in Arizona’s congressional districts

Voter Registration Maps By October 15, 2018 Tags: , , No Comments

Here is an interactive map that shows the distribution of political party affiliations in Arizona’s nine congressional districts. If you hover over a district, the map will display the district number, plus statistics about which voters live in that district. It also shows the current representative for each district. You can zoom in on the map for greater detail.

Democrats hold some degree of advantage in five of the nine districts. Of these five, two lean heavily in favor of Democrats: Ruben Gallego’s District Seven has a 31.6 percent advantage over Republicans, and Raúl Grijalva’s District Three has a 22.7 percent advantage.

The remaining three Democrat-leaning districts have far slimmer advantages. Tom O’Halleran’s District One leans Democratic by 5.5 percent, and Kyrsten Sinema’s District Nine leans Democratic by 3.3 percent. Martha McSally’s District Two is Arizona’s most competitive congressional district, with Dems holding an advantage of .9 percent.

Arizona has four solidly Republican congressional districts, each with a registration advantage of 15 points or more. David Schweikert’s District Six has a 15 percent advantage over Dems. Debbie Lesko’s District Eight has a 16.9 percent advantage. Andy Biggs’ District Five has a 21.2 percent advantage. And Paul Gosar’s District Four—Arizona’s most heavily GOP congressional district—has an advantage of 26.1 points.


An interactive map of Arizona’s voting precincts

GIS By September 4, 2018 Tags: , , 2 Comments

Here is an interactive map that shows the geographic boundaries of Arizona’s 1,495 voting precincts. If you hover your mouse over a precinct, the map will also display the legislative district, congressional district, and county in which the precinct is located. The map is zoomable, and will zoom automatically if you click your mouse on a precinct,

Each county is responsible for naming its precincts, and different naming conventions are followed from one to the next. The precincts of Cochise, Coconino, Gila, and Maricopa counties have names as opposed to numbers, and do not have corresponding numbers. The counties of Pima and Yuma have only numbers, not names. The counties of Apache, Graham, La Paz, Mohave, Navajo, and Pinal all have both numbers and names.

My hope is this map might serve as a starting point for more interesting maps to come, such as choropleths that show partisan voter distribution, and vote results from past elections. You can view a choropleth map I made last year showing partisan advantage in Pima County’s voting precincts by clicking here.


Exploring Tucson’s neighborhood associations

GIS By August 3, 2017 Tags: , , No Comments

Here is an interactive Leaflet map showing Tucson’s 141 registered neighborhood associations, as indicated by shapefiles obtained from the Pima County GIS library. You should see individual neighborhoods highlight as you move your cursor around the map. If you click on one, the map should zoom to that neighborhood. You can also zoom with your mouse. If you hover your cursor over a neighborhood, the map will display the neighborhood’s name, ward, and other key details.


Homeowners receiving Arizona’s Historic Property Tax Reclassification in Pima County

GIS By February 20, 2017 Tags: , , , , 4 Comments

For its recipients, Arizona’s Historic Property Tax Reclassification is a pretty great deal. Homeowners who qualify get their assessment ratios slashed from 10% to 5%, cutting their property tax bills in half. This map shows the residential properties in Pima County that receive this benefit. If you zoom in and click on an individual parcel, the map should display that property’s street address and parcel number. For a re-sizable window in a separate tab, click here.

For more on what it takes to qualify for the Historic Property Tax Reclassification, and how to apply, click here.


Homeowners versus renters in Pima County

GIS By February 19, 2017 Tags: , , , 2 Comments

This map attempts to visualize Pima County’s respective distributions of residential property that is owner-occupied, and residential property that is not. The latter category consists almost entirely of rental property, but also includes a few other instances of non-owner-occupied property, such as vacation homes, certain group homes, and bed-and-breakfasts. It is represented in orange; the owner occupied property is represented in blue. To view this map in a separate, re-sizable window, click here.

Only residential property is represented on this map. Included in the white areas are public rights-of-way, government property, commercial property, agricultural property, and a number of other non-residential property types. This map distinguishes owner-occupied properties from other types based on their legal class, according to the Pima County Assessor’s records. For more information about legal classes, click here.


A closer look at the 2016 presidential election in Pima County

GIS By February 5, 2017 Tags: , , , , 3 Comments

This map shows each of Pima County’s 248 voting precincts with a shades of blue and red to indicate the respective degrees to which they favored the Democratic or Republican candidate, Hillary Clinton or Donald Trump. You can zoom in for a closer look, and click on any precinct for more detailed information. For a resizable version in a separate window, click here.

Although they were on the ballot, I chose to ignore vote totals for the Libertarian and Green party candidates for the purpose of this map. I also ignored write-in votes, over-voted, and under-voted ballots. None occurred in percentages that exceeded single digits, with the exception of Gary Johnson, who received 42 out of 412 votes—10.19% of the total—in precinct 114.


A GIS tour of Arizona’s golf courses

GIS By February 3, 2017 Tags: , , No Comments

This map shows Arizona’s 353 golf courses. (For a resizable version in a separate window, click here.) If you click on one of them, the map should display the course’s name, number of holes, whether it is public or private, and in some cases, what type of water source it uses. (The source file only contained this data for a limited number of courses.)

The GIS data shown here is provided by the Central Arizona Project, and was obtained via the AZGEO Clearinghouse, an great resource for GIS professionals and enthusiasts.