Saturday, March 07, 2015
Mapping the Cape Fire
Eyewitness News has created a Google Map showing the extent of the wildfires that raged around the Cape Town south peninsula last week.
The fire has affected around 5,000 hectares of land. To help visualize the true extent of the fire Eyewitness News' map, Cape Fire - A Comparison, allows you to overlay a polygon of the affected area overlaid on other locations around the world. The map provides a number of quick links to see the 5,000 hectares overlaid on the map of a number of major cities in South Africa and elsewhere around the world. You can also use an address search to see the polygon overlaid on any other location.
Eyewitness News appear to have created their own algorithm to adjust the size of the polygon relative to the latitude of the mapped location. The Google Maps API actually includes its own geodesic function which you can apply to polygons to enable them to be resized relative to their position on the map. You can view an example of this on this Google Maps API Draggable Polygons code example.