Greenness (NDVI)

Howdy, I’m the Normalized Difference Vegetation Index, but only my mother calls me that, you can just call me ‘NDVI’. I’m here to tell you how green your surroundings are! Satellites measure me from space to capture seasonal differences in greenness. My greenness comes from anything with chlorophyll, a small grassy patch to large bushes and trees. The greener plants the higher my NDVI value, no wonder my winter body looks different than my summer body. My natural features bring out the best in people by improving psychological and physical health outcomes by reducing heat, air pollution and exposing people to nature. I can detect public or private green spaces, but I cannot tell you their quality. Higher levels of greenness have been associated with higher birth outcomes and student performance including higher test scores and lower chronic absenteeism as well decrease all-cause mortality. A high NDVI value helps reduce urban heat island, pollution and water runoff, and increase tree canopy and resilience. More trees and plants may also mean more maintenance. Inequities in the amount of surrounding greenness creates an environment where even within the same city, one neighborhood is several degrees hotter than another one. To make sure that the effects of harmful weather, such as extreme heat, do not place an unequal burden on disadvantaged communities, designers should incorporate strategies to increase greenness in every community.