Making 3D Maps of Air Pollution in ArcGIS

Introduction

This tutorial guides you through the process of creating 3D maps of air pollution using ArcGIS. By leveraging census tract data and PM2.5 air quality measurements, you will learn how to visualize air pollution levels geographically, which is crucial for urban planning, public health assessments, and environmental studies.

Step 1: Download Census Tract Shapefile and Load It into ArcMap

• Access the TIGER/Line shapefiles for U.S. counties from the Census website.
• Download the appropriate census tract shapefile for your area of interest.
• Open ArcMap and load the shapefile:
  • Click on "Add Data" and navigate to the location of your downloaded shapefile.
  • Select the shapefile and click "Add."

Step 2: Calculate the Average PM2.5 for Each Census Tract

• Obtain PM2.5 air quality data from the EPA.
• Ensure the data is formatted correctly for analysis.
• Use the "Spatial Join" tool in ArcMap to associate PM2.5 data with census tracts:
  • Open the "Spatial Join" tool from the Geoprocessing menu.
  • Set the target feature as your census tract shapefile and the join feature as the PM2.5 data.
  • Configure the join type to "KEEP_ALL" to retain all census tracts.

Step 3: Perform Zonal Statistics

• Navigate to the "Zonal Statistics" tool in ArcMap:
  • Select your census tract layer as the input raster, and the PM2.5 data as the zone.
  • Choose the statistic type as "MEAN" to calculate the average PM2.5 levels.
• Run the analysis to generate a new layer that contains the average PM2.5 values for each census tract.

Step 4: Join the Statistics to Census Tract and Map Them

• Use the "Join" tool in ArcMap to merge the average PM2.5 statistics with the census tract layer:
  • Right-click on the census tract layer and choose "Joins and Relates" > "Join."
  • Select the field that corresponds to the PM2.5 statistics.
• Once joined, symbolize the census tracts based on PM2.5 levels:
  • Open the layer properties, go to the "Symbology" tab, and choose a color ramp to represent different pollution levels.

Step 5: Visualize in ArcScene

• Open ArcScene to create a 3D visualization of your data:
  • Import the mapped census tract layer into ArcScene.
  • Adjust the elevation settings to reflect PM2.5 data, allowing for a 3D representation of pollution levels.

Step 6: Make a 3D Map

• Use the “3D Analyst” tools to enhance your visualization:
  • Apply extrusion based on PM2.5 values to give height to the census tracts.
  • Customize viewing angles and lighting to improve the visual impact of your map.
• Save your 3D map as a scene file for future use or presentations.

Conclusion

In this tutorial, you learned how to create 3D maps of air pollution using ArcGIS by downloading census tract shapefiles, calculating average PM2.5 levels, performing zonal statistics, and visualizing data in 3D. These skills are essential for effectively communicating air quality issues and can be applied to various public health and environmental studies. Consider exploring additional data layers or other environmental factors to enrich your analysis further.