Visualization and Analysis of Guatemala NDVI using Python and Google Earth Engine
Course: Computer Programming for GIS
Date: October 2020
Author: Rachel Corcoran-Adams
Background: A code was created in Google Earth Engine to create an animated gif of NDVI in Guatemala. Using MODIS, a moderate resolution satellite imaging system and its NDVI band, a common reflectance-based vegetation index, this image is mapped to a color gradient from tan to dark green which represents low to high photosynthetic capacity.
Data: MODIS sensor NDVI band obtained through Google Earth Engine's Image Collector
Methods: This was done by first, defining the region of interest and animation frame metrics, then joining images from the 16-day composite window, reducing the composite groups by median to produce the animation frames, and then defining the parameters for visualization and converting the data into RGB images.
Outcome: The results show a tide-like latitudinal shift in vegetation which is accredited to the sun's declination moving between 23.5° north and 23.5° south, relative to the equator, throughout the year. We see a similar seasonal pattern in vegetation productivity in Guatemala shown in the gif below.
You can access the code on GitHub: Here
Date: October 2020
Author: Rachel Corcoran-Adams
Background: A code was created in Google Earth Engine to create an animated gif of NDVI in Guatemala. Using MODIS, a moderate resolution satellite imaging system and its NDVI band, a common reflectance-based vegetation index, this image is mapped to a color gradient from tan to dark green which represents low to high photosynthetic capacity.
Data: MODIS sensor NDVI band obtained through Google Earth Engine's Image Collector
Methods: This was done by first, defining the region of interest and animation frame metrics, then joining images from the 16-day composite window, reducing the composite groups by median to produce the animation frames, and then defining the parameters for visualization and converting the data into RGB images.
Outcome: The results show a tide-like latitudinal shift in vegetation which is accredited to the sun's declination moving between 23.5° north and 23.5° south, relative to the equator, throughout the year. We see a similar seasonal pattern in vegetation productivity in Guatemala shown in the gif below.
You can access the code on GitHub: Here