Where to Place Campaign Headquarters in North Texas
UTA Libraries: GIS Workshop Series
Exercise Objective: Locate the best possible sites in North Texas to place campaign headquarters for a Hispanic democrat running in for Governor. North Texas is defined as North of Austin.
Joshua Been GIS Librarian UTA Libraries Voice: Fax: Email: Web: (817) 272-5826 (817) 272-3924 firstname.lastname@example.org http://libraries.uta.edu/gis/index.html
Date Place Additional GIS Assistance UTA Libraries Contact Joshua Been, GIS Librarian -- OR -Walk-In GIS Assistance, GIS Facility (Central Library 510) Saturday 12:00 – 8:00
Data Sets Used:
All Data Sets Located in the Geodatabase: CampaignHQ.mdb Except for the 4 DOQ Files
Spatial: o Locations of all cities in North Texas o (CampaignHQ.mdb/Cities) o Texas House District Shapes in North Texas o (CampaignHQ.mdb/CongressDistNorth) o Block Group Shapes in North Texas o (CampaignHQ.mdb/Texas_Block_Groups_North) o County Shapes in North Texas o (CampaignHQ.mdb/CountiesNorth) o DOQ Files o (DOQ/) Attribute: o 2002 o o o General Election Results by Texas House Districts (CampaignHQ.mdb/BG_Attributes) File contains U.S. Senate, Texas Governor, and Attorney General Source: Texas Legislative Council: District Election Analysis http://gis1.tlc.state.tx.us/static/pdf/plan1369h~2002gen.pdf o Numbers of Hispanic Residents by Block Group o (CampaignHQ.mdb/BG_Attributes) o Source: Census 2000 SF3 http://factfinder.census .gov/ o Median Household Income by Block Group o (CampaignHQ.mdb/BG_Attributes) o Source: Census 2000 SF3 http://factfinder.census .gov/ o Marital Status by Block Group o (CampaignHQ.mdb/BG_Attributes) o Source: Census 2000 SF3 http://factfinder.census .gov/
Overview of Procedure Outcome: Find the best locations which include the following characteristics: o As close as possible to a city o Within a democratic area o As close as possible to large concentrations of Hispanics o As close as possible to middle and lower middle class communities o As close as possible to communities where a high proportion of the adult population is married
Steps: Open ArcMAP o Start / Programs / ArcGIS / ArcMAP
FIRST WE WILL VIEW OUR VECTOR DATA
View the following map layers by clicking on the button to add layers. 1. Location of cities in North Texas. a. (CampaignHQ.mdb/Cities) 2. Texas House District Shapes in North Texas a. (CampaignHQ.mdb/CongressDistNorth) 3. Block Group Shapes in North Texas a. (CampaignHQ.mdb/Texas_Block_Groups_North)
SECOND WE WILL JOIN OUR ATTRIBUTE DATA
Join the 2002 General Election Results to the CongressDistNorth layer. o Right-click on the CongressDistNorth layer on the left and select Properties. o Select the Joins & Relates tab o Under Joins, click on the Add button. o Choose the Field: H_ o Choose the Table: Browse to CampaignHQ.mdb/ElectionResults o Choose the Field: Districts
o OK o Apply o To view the distribution of our attributes: Select the Symbology Tab (still in properties) Under the Show menu, select Quantities/Graduated Colors Under Value, select ElectionResults.Gov_D Under Classification, select Natural Breaks and 10 classes.
OK. Click the empty shadow box next to the Texas_Block_Groups_North on the left to view the layer.
Join the attribute data to the Texas_Block_Groups_North layer. o Right- click on Texas_Block_Groups_North o Select the Joins & Relates tab o Under Joins, click on the Add button.
Choose the Field: STFID Choose the Table: Browse to CampaignHQ.mdb/BG_Attributes Choose the Field: KEY OK Apply To view the distribution of our attributes: Select the Symbology Tab (still in properties) Under the Show menu, select Quantities/Graduated Colors Under Value, select BG_Attributes.Hispanic o Under Classification, select Natural Breaks and 10 classes. o Click the empty shadow box next to the Texas_Block_Groups_North on the left to view the layer. o o o o o o
THIRD WE WILL CALCULATE DISTANCES FROM CITIES IN NORTH TEXAS
Ensure that the Spatial Analyst Feature is Enabled o From the menu at the top, click ‘Tools’, and select ‘Extensions’. o Click the shadow box next to Spatial Analyst if it is not checked. o Close o From the menu at the top, click ‘View’, and select ‘Toolbars’. If there is not a check next to Spatial Analyst, click Spatial Analyst. o The toolbar that appears can be docked Configure Spatial Analyst for This Project o Click the pull-down menu for Spatial Analyst and select Options. o In the General tab, set the Working Directory to c:\campaign\ by typing this in the space provided.
o In the Extent tab, set the Analysis Extent to ‘Same as Layer “Tarrant_Block_Groups’
o OK o If you receive a message asking you to create this new campaign directory, click yes. Measure Out Distances From Cities o Click the Spatial Analyst pull-down menu, and select Distance, and then select Straight Line. o Change Distance To to Cities. o OK. o If you cannot see the newly created layer, un-check the shadow box next to the layers above it on the left. Configure the Newly Created Distance to Cities based on a 10-Class Frequency Divided by Natural Breaks. o Right-click the Distance to Cities layer on the left and select Properties. o Select the Symbology Tab
o o o o
Click on the Classify… button Under Classification Method, select Natural Breaks Select 10 Classes OK…OK
FOURTH WE WILL CREATE FOUR RASTER IMAGES FROM OUR DISTRIBUTED ATTRIBUTES
Create Four (4) Raster Images for Our Three Attribute Maps (Election Results, Hispanic Population, Median Income, and Marital Status) o Click on the Spatial Analyst pull-down menu o Select Convert and then select Features to Raster o Input Features: CongressDistNorth o Field: BG_Attributes.Gov_D o Output Raster: c:\campaign\DemoGov
o OK o Repeat process for three other attributes, this time using Tarrant_Block_Groups_North as the Input Feature with the following three Fields: BG_Attributes.Hispanic BG_Attributes.MedianIncome BG_Attributes.Married_Per
o OK Set The Four Newly Created Raster Images to a 10-class frequency divided by Natural Breaks.
FIFTH WE WILL CLASSIFY OUR RASTER IMAGES TO A COMMON 10 POINT SCALE (10 BEING THE MOST DESIRABLE QUALITY)
Classify five (5) raster images to a common 10 point scale. o Five raster images: (Distance to Cities, Election Results, Hispanic Population, Median Income, and Marital Status)
o o o o
Click on the Spatial Analyst pull-down menu. Select Reclassify… Input Raster: Distance to Cities Click on the Classify… button to ensure a 10-class frequency.
o Ensure that the new values represent their assignment as you see fit, with a 10 ranking the highest and a 1 ranking the lowest. o OK. o Repeat for the other four raster images.
SIXTH WE WILL CALCULATE THE WEIGHTS AND COMBINE THE FIVE RECLASSIFIED FILES
[Fun Part] Calculate the Weights and Combine the Reclassified Files
o o o o o o o o o o o Click on the Spatial Analyst pull-down menu. Select Rastor Calculator Double-click on Reclass of DemoGov Single-click on the asterisk (multiply) Assign a value between 0 and 1 Single-click on the plus Double-click on another of the 5 reclassified files Single-click on the asterisk (multiply) Assign a value between 0 and 1 Continue with all of the reclassified files. When complete, click Evalauate.
Reclassify the Calculation layer to a 1-10 scale. Select o o o o o o Only to view 9 and 10 of the Reclassified Calculation Layer Click on the Spatial Analyst pull-down menu. Select Rastor Calculator Double-click on Reclass of Calculation Single-click on the greater-than sign Single-click on 8 Evaluate.
Add the Counties layer (CampaignHQ.mdb/CountiesNorth). Add the four (4) DOQ Images for East Arlington(DOQ/). These are the best locations. Try playing around with the weights.