Updating land cover maps satellite images
The land cover maps were developed at Boston University in Boston, MA., using data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA’s Terra satellite.
The maps are based on a digital database of Earth images collected between November 2000 and October 2001.
"With data collected over several years," says Friedl, "we will be able to create maps that highlight global-scale changes in vegetation and land cover in response to climate change, such as drought.
We'll also be establishing the timing of seasonal changes in vegetation, defining when important transitions take place, such as the onset of the growing season." Launched December 18, 1999, Terra is the flagship of the Earth Observing System series of satellites and is a central part of NASA's Earth Science Enterprise.
An important breakthrough for these maps is the merging of those multiple looks into a single image.
In addition, advances in remote sensing technology allow MODIS to collect higher-quality data than previous sensors.
Although no systematic work has been conducted in recent years, displacement of people related to civil unrest is frequent and commonly results in increased pressure on natural resources, with deforestation and degradation of woodlands for biofuel production and land conversion to agriculture.
New NASA land cover maps are providing scientists with the most refined global picture ever produced of the distribution of Earth’s ecosystems and land use patterns.