Data Cardinality

Mapping the number of jobs in North Carolina


The goal of this project is to map the number of jobs created in North Carolina House and Senate districts for the NC House and Senate members.

Analysis Procedures

The overall strategy was to summarize and map the total number of jobs by ZIP Code using table and spatial joins. Two separate maps, one for house district and the second for the Senate, were developed.  The data for this task include ZIP Code layer file downloaded from ArcGIS online, job survey Excel file and the House and Senate districts shapefiles. ArcGIS 10.6 software was used for this task.

I added the NC House and Senate district shapefiles, US ZIP Codes points layer and the job survey Excel file to ArcMap. From the attribute table, I selected NC zip codes and exported the selection as the new layer. Next, I added the job survey results excel file to the table of contents and from the attributes table, I selected records only from North Carolina. I checked that the variable of interest in the excel file –  EMPLOYEE_SUM – is numeric and then joined the NC zip codes point shapefile with survey results excel datasheet.  The new zip code and employee shapefile contain data from the survey and zip code point file.  Lastly, I performed the spatial join joining the zip code point data to house and Senate districts polygon shapefile.  I checked the option Sum and exported the data as two new shapefiles, one each for House and Senate district jobs.



Application & Reflection

Table joins and spatial joins have wide applicability in public health.

Problem: Exposure to lead has been related to several childhood morbidities.  In Mecklenburg County, NC., there are five zip codes that are considered high priority areas.  Residents living in these five priority areas have a higher prevalence of chronic diseases, including hypertension, heart disease, and mental health.  Most of the houses in the zip codes are old and were built when lead was used in paint.

Data required: Excel sheet with data on blood lead levels of children.  ZIP Codes are available to download from the Mecklenburg County Open Mapping website.

Analysis procedures: I will use tabular data (Excel sheet) to join the blood lead levels data to the Mecklenburg County zip codes shapefile.