Lesson Report 4: Address Geocoding by Diana Jo Lau Introduction Home Testing Incorporated is a company that produces testing kits for radon and other hazards. Currently, HTI have compiled the results of addresses testing the levels of radon using the company's home testing kit. "Radon is a radioactive gas that is colorless, odorless, and tasteless. It is formed by the natural radioactive decay of uranium rock, soil and water." (King, Walrath, & Zeiders, 1999-2013). Radon is measured in picocuries per liter (pci/l); the EPA suggests to remediate your home if radon levels are 4 pci/l; radon levels below 4 pci/l still bring some risk to your health. Health effects of radon include the rist of lung cancer (EPA, 2012). Lesson Objectives - To set the geocoding layer properties and perform a batch match - To apply an address locator. - To match records using the interactive rematch. - To use the Union tool in ArcToolbox to union two layers. - To merge two layers. - To use the Find tool to locate a single address. - To create thematic maps to describe the data analyzed. Project Criteria 1. To map all geocoded addresses and locate addresses of potential radon hazards. 2. To map the six new addresses (Try This!) and locate addresses of potential radon hazards. Results and Discussion The GIS data was downloaded from the link provided in Lesson 4. The data was already projected to NAD83 Albers Conical Equal Area in units of meters (King, Walrath, & Zeiders, 1999-2013). Geology and soils layers were added and their symbology was modified to show the type of geology and soil layers. Later these two layers were joined using the Union tool. The address locator was included in the files downloaded. Geocoding was performed using the addresses (reference) table provided and the address locator. The types of fields chosen were Address and Zip code; it is important that the type of fields match in between the address locator and the reference table. Unmatched records were matched using the Interactive Rematch. As previously mentioned, the soils and geology layers were combined using the
Union tool, then a new field was added to calculate the total radon potential (radon potential of soil + radon potential of geology). The total radon potential data was classified in quantiles and three (3) classes (low, medium, high). Figure 1 shows the geocoded addresses and the radon potential by areas. The single address searched is shown in detail in Figure 2. The Try This! exercise results are shown in Figure 3, and the matched addressed is shown in more detail in Figure 4. A successful merge in between the geocoded addresses is shown in the attributes table, Figure 5. Figure 1 Radon risk zones and affected locations. The highest radon potential is mostly located in the south and southwest area of the map.
2581 Old Gatesburg, 15303 Figure 2 Southwest area of map in Figure 1 magnified. The address location (green star) is located in a high risk area. Figure 3 Radon risk zones and affected locations including six (6) additional addresses. Five (5) of the additional addresses are located in high risk zones.
485 Arbor Way, 15303 Figure 4 Southwest area of map in Figure 3 magnified. The address to match (light blue star) is located in a high risk area. Figure 5 Table of geocoded addreses including the six additional addresses (highlighted).
Conclusion As seen in Figures 1 and 3 most of the addresses located in the south and southwest area are in high risk of radon. Geocoding is essential for local and state agencies to identify addresses, for example, addresses in need of emergency services. This projects is a good example of geocoding and geospatial analysis in environmental applications. References EPA (2012). A Citizen's Guide to Radon: The Guide to Protecting Yourself and your Family from Radon. Indoor Air Quality. EPA 402/K-12/002. Retrieved March 20, 2013 from http://www.epa.gov/radon/pdfs/citizensguide.pdf King, E., Walrath, D & Zeiders, M (1999-2013). Problem-Solving with GIS, Lesson 3, /Part 1, Section b. The Pennsylvania State University World Campus Certificate/MGIS Programs in GIS. Retrieved March 13, 2013. This document is published in fulfillment of an assignment by a student enrolled in an educational offering of The Pennsylvania State University. The student, named above, retains all rights to the document and responsibility for its accuracy and originality.