What is a Radius Map? Radius mapping is the process of creating a circle around a specific point on a map, such as a city address or area latitude/longitude point. When it comes to creating a business operating area of interest, you can use a radius map to query imported data or to gather ZIP codes or counties for export. Radius Around Point. You can use this tool to find the radius around a point on the map. First type in the radius required in kilometers or miles and then click on the map at the center of where you wish the circle to appear.
I'm incredibly new to creating these types of maps, but I'm trying to create a coverage map not unlike the cell companies show their coverage. Our database simply has lists of ZIP codes that our service covers and I want to display these on a map, colored in, like the cell phone companies do.
I have figured out how to do this on my own (using QGIS and joining my CSV list with the shapefile from the USPS of zip codes)... But the thing I can't figure out how to do is to show a radius around each zip coded area. Our coverage extends 100 miles (50 miles in each direction) from the center point of each zip code.
With a list of over 32,000 zip codes, is there a way to easily extend the coloring area around each zip code to include this extra area?
nmtoken
2 Answers
'show a radius around each zip coded area. Our coverage extends 100 miles (50 miles in each direction) from the center point of each zip code.'
- Convert your Zip Codes to Centroids. Vector - Geometry Tools - Polygon Centroids.
- Buffer the Points. Vector - Geometry Tools - Buffer
Some things to consider.
Use a projected coordinate system that is in meters then your buffer distance will be 885139 meters. I would suggest SR-ORG:7301 as you are working in the USA and desire a unit that is stable (ie not degrees).
Once you've done your join, right-click the joined polygon layer and 'Save as' and create a new shapefile containing all the joined data. (note: here you can change the coordinate system as you save to the new file)
Then Use the Vector > Geometry Tools > Polygon centroids to turn all your zip code polygons to points
Then use Vector > Geoprocessing > Buffer to buffer your points by 50mi
But - you'll have to make sure your zip code polygons (or points) are in a coordinate system that is in FEET so when you use the buffer tool
So - what area do your zip codes cover?
DPSSpatialDPSSpatial