Making Air Pollution Maps from Scratch

Introduction

This tutorial will guide you through the process of creating air pollution maps from scratch, using data from the Environmental Protection Agency (EPA) and ArcMap software. Understanding air quality and visualizing it can help in public health assessments and urban planning.

Step 1: Download EPA Data

• Visit the EPA website to access air quality data.
• Look for the dataset related to PM2.5 (particulate matter with a diameter of 2.5 micrometers or smaller).
• Download the relevant files, ensuring you have data for the appropriate years and locations.

Step 2: Calculate Yearly Average PM2.5 for Each Station

• Open the downloaded data in a spreadsheet or data analysis software.
• Calculate the yearly average for PM2.5 concentrations at each monitoring station.
  • Use the formula:

    Yearly Average PM2.5 = Sum of monthly PM2.5 values / Number of months 
    

• Organize this data in a clear format, such as a table, for easy reference.

Step 3: Load Data into ArcMap and Map Stations

• Open ArcMap software.
• Import the PM2.5 dataset you prepared.
• Add a shapefile for the geographic boundaries (you can download TIGER/Line shapefiles for US counties).
• Ensure to match your PM2.5 data with the correct geographic locations.
• Create point features for each monitoring station on the map.

Step 4: Make Continuous Surface Using IDW Interpolation

• Use the Inverse Distance Weighting (IDW) method to interpolate PM2.5 values across the area.
• In ArcMap:
  • Navigate to Spatial Analyst Tools.
  • Select Interpolation and then choose IDW.
  • Set your point feature layer as the input and specify the output raster.
• Adjust IDW parameters (such as power and cell size) based on your analysis needs.

Step 5: Map Making

• Customize your map to enhance its clarity and visual appeal.
• Add elements such as:
  • Title
  • Legend
  • Scale bar
  • North arrow
• Choose appropriate color schemes to represent PM2.5 levels effectively.
• Save and export your final map for presentation or further analysis.

Conclusion

In this tutorial, you learned how to create air pollution maps from scratch, using EPA data and ArcMap software. The steps included downloading data, calculating yearly averages, mapping stations, performing IDW interpolation, and finalizing your map. With these skills, you can visualize air quality data for various applications, contributing to public awareness and informed decision-making regarding air pollution. Next, consider exploring more advanced mapping techniques or integrating additional datasets for comprehensive analysis.