It works by reading the absorption and reflecting of both visible and near-infrared light off of all types of objects, such as concrete, water, vegetation, and dirt. The different values give information regarding the type and abundance of vegetation in a given location. This information is then used by ecologists and conservation biologists to predict the impacts of potential changes in the environment on the animal inhabitants.
This figure shows the basic process by which NDVI works. The readings received from the vegetation give information as to the makeup of the environment, and from there the biodiversity and species density can be inferred from previous research. This data can then be entered into models which can help to predict the effects of climate change and degradation.
The authors state that NDVI and other types of satellite imaging are part of the future of ecology. They offer types of information that could not easily be gathered from the earth's surface, and will make predictions about future changes more accurate.
, , , , & (2005) Using the satellite-derived NDVI to assess ecological responses to environmental change. Trends in Ecology and Evolution, 20, 503–510.
Probably the most interesting thing for me so far, from learning about GIS, is seeing how a view of Earth from space can provide new types of information to so many different fields, and how this allows us to think more ecologically. Were these things we had considered previously but were not able to measure - e.g. the land cover use article, this type of satellite information?
ReplyDeleteI took a class in Conservation Biology that talked about this technology and how scientists use this to track habitat loss and track species. Nasir, I think that yes these are things that people have thought about for a long time but without a visual measurement, it truly is hard to see the affects of habitat loss. This is one benefit of GIS, being able to provide this type of information.
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