In this lab, the Google Earth Engine (GEE) is used to extract NDVI data, which a common reflectance based vegetation index from MODIS (Moderate Resolution Satellite Imaging System). The NDVI data is then processed and visualized using Google earth engine and java script, as well as the NDVI data. The resulting gif shows the vegetation cover changes across the boundary of India over the past two decades based on the Landsat-derived Normalized Difference Vegetation Index (NDVI). In the existing gif, NDVI is mapped to a color gradient from tan to dark green representing low to high photosynthetic capacity (low to high vegetation cover/density/productivity). Each frame is a 20 year Median NDVI for the same 16 day composite from 2000 to 2019. We can see that the northern and the western part of India (towards ladakh and Rajasthan) the photosynthetic capacity remained low while the capacity increased on average for the overall country starting from the north eastern end of the boundary reaching far south which implies that there is an increase in the vegetation index of the country over the past decades.
The variability in the weather pattern of India can be observed in the attached GIF and the forest vegetation in some regions of India (typically western ghats) are typically under most stress during the dry summer months. As we can see the areas around the state of Rajasthan are mostly affected throughout the animation period. Arid region of India shows vast variation in climate and vegetation which is very critical for agriculture, livelihood and cattle stock of India. MODIS NDVI is helpful in quickly assessing vegetation changes in response to rainfall as well as due to anthropogenic interventions in arid regions. (Borana & Yadav, 2019)