Tuesday, May 10, 2016

How Green is Your Town?

The Berliner Morgenpost has analysed hundreds of satellite images in order to determine Germany's greenest towns. These are Germany's Greenest Towns ranks Germany's 79 major cities in order of how much vegetation they have.

Most previous analysis of Germany's greenest cities has been determined by the amount of public parks and public recreational areas a city has, The Berliner Morgenpost has used detailed analysis of satellite imagery to provide a more accurate picture of the amount of vegetation in each city. Their analysis includes other natural areas, such as planted roofs, private gardens, urban trees and private backyards.

To analyse the satellite imagery the Berliner Morgenpost developed this EarthEngine Script. The script examines Landsat 5, Landsat 7 and Landsat 8 satellite images, with less than five percent cloud cover, taken in the summer months of June and July 2005-2015. Using the Normalized Difference Vegetation Index the Berliner Morgenpost was able to determine how much greenery was present in each 30 by 30 meter square in the imagery.

To create the interactive map it appears that the Berliner Morgenpost has created a heat map of the country, where the percentage of greenery determined by the NDVI analysis is represented on the map with a green color ramp. The map tiles were created in Tilemill and made into an interactive map using the Leaflet mapping platform.

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