Siren Buffer Analysis

Summary

The City of Lansing had complaints of some residents not being able to hear the sirens during an emergency and wanted to figure out where the best place to put additional sirens would be. After some analysis, three new siren locations were proposed on time and within budget.

My Part

Lead GIS Analyst

Skills Learned + Demonstrated

• Proximity analysis

• Extrapolation of incomplete data

• Professional proposal write-up

The Proposal

The Lansing Emergency Management Office did not have a map detailing where all of the emergency sirens were located. Additionally, the sirens all had varying radii that they can be heard from. I was tasked with finding out where additional sirens were needed to have as much coverage of the city as possible.

What I Did

I was given a list that included all the sirens within the city borders with their nearest crossroads provided. Also available at my disposal were a few maps that other neighboring cities had generated for their sirens (many of the other city's sirens audible radii bled into Lansing's boundaries). I had the model numbers for most of these sirens that I could use to research the radius that each could cover. I generated ellipses around each point with radii that were dependent on the model number. Using various ArcGIS tools, I simplified the generated polygons and ended up with a map that displayed three prominent zones that were uncovered.

The following image is a simplified version highlighting the three problem areas in red:

The Result

In my write-up, I proposed that three new sirens, each with a radius of about 1.5 mi. be placed at the centroid of each of the three large problem areas.