How To Extract Forest Or Vegetation Cover In Your City Using Satellite Imagery

Are you thinking to analyze how much of city is covered with vegetation or forest, there are many houses having big lawns with boundary wall how to get data, satellite images have solved this problem. You can now very easily get vegetation in your city or country using satellite images.

Image by Free-Photos from Pixabay

How to do it

- Download a satellite image
Get GIS Software
- Perform analysis
- Generate a Map

Your first step is to download any satellite imagery of your area from any free satellite data source such as USGS Earth Explorer or any other. Multi-spectral Imagery that captures scene in many bands which are usually available free of cost.
Downloading Raster Imagery using Earth Explorer

Follow URL https://earthexplorer.usgs.gov/ a screen as shown appears, get yourself registered by clicking Register Button as shown, once you are registered you can login to download imagery.

USGS Earth Explorer Interface

Enter Search criterion, add Address, e.g. Islamabad
Zoom to Islamabad, Select USE map option for time being you can use KML, Shapefile etc.
Specify Date, click Data Set
E.g. I select Landsat Archive, Pre Collection -> Landsat 7 ETM+ SLC- OFF(2003-Present)
Click Additional Criterion, Specify Cloud cover < 10 %
Proceed to Results, Check browse to Overlay Option as shown in screen

Browse to overlay

- Select Download and Download Level 1 product.

Get a free software here is a list of many available
Perform Analysis

Calculate NDVI ( Normalized Difference Vegetation Index )

Using GIS Software, Calculate a formulae (NIR-RED/NIR+RED), NIR means Near InfraRed Band, Red is Red Band which you have recently downloaded.

Click process or execute option in your software package

Output will be a raster map, to interpret
The value range of an NDVI is -1 to 1. Negative values of NDVI (values approaching -1) correspond to water. Values close to zero (-0.1 to 0.1) generally correspond to barren areas of rock, sand, or snow. Low, positive values represent shrub and grassland (approximately 0.2 to 0.4), while high values indicate temperate and tropical rainforests/ healthy vegetation (values approaching 1).
Text Source (https://www.sentinel-hub.com/eoproducts/ndvi-normalized-difference-vegetation-index)

Where you can use it:

Forestry, Agriculture, Tax Collection of lands, Ecology, and many others…

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