Traditional satellite-based mapping of vegetation
vigor and amount is based on the way vegetation
interacts with red and infrared light. Occasionally,
however, those two signals are not enough. MODIS
measures light reflected from Earth at a variety of
wavelengths, and the Arizona researchers incorporate
the additional information into their Enhanced
Vegetation Index (EVI).
The EVI has increased sensitivity within very dense
vegetation, and it has built-in corrections for several
factors that can interfere with the satellite-based
vegetation mapping, like smoke and background
noise caused by light reflecting off soil.
The bi-weekly and monthly vegetation index maps
have wide usability by biologists, natural resources
managers, and climate modelers. They can track
naturally occurring fluctuations in vegetation, such
as seasonal changes, as well as those that result from
land use change, such as deforestation. The EVI can
also monitor changes in vegetation resulting from
climate change, such as expansion of deserts or
extension of growing seasons. Educational levels: Undergraduate lower division, Undergraduate upper division, Graduate or professional