GE Grids

Post submitted by Andrew Jacobson.

What do you think of when you hear the words “remote sensing?” Or what about “wildlife corridors?” While both of these remain somewhat esoteric concepts, they share an important link. Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object1, in this case the earth from satellites or aircraft. A wildlife corridor is an area of habitat connecting wildlife populations separated by human activities or structures2. As it turns out, remote sensing is often essential for identifying wildlife corridors (often linked via animal tracking). An essential first step in working out where lions and other big carnivores are likely to survive, or traverse, is the accurate identification of the distribution and extent of human converted land cover (such as cities and croplands). However, even with remote sensing, this task can be quite difficult.

In light of the difficulty of obtaining accurate land cover maps, particularly in developing countries; researchers with National Geographic’s Big Cats Initiative designed a new open-access web application, GE Grids3. This tool is the first of its kind, allowing users to create land use land cover maps for free using high-resolution satellite imagery available on Google Earth. Researchers applied GE Grids to identify the distribution of human converted land cover across East Africa.

The researchers discovered that nearly 30% of East Africa (Kenya, Tanzania, Uganda, Rwanda and Burundi) is converted to human land cover. Most dramatically, over 80% of densely populated Rwanda and Burundi are occupied by humans, leaving little room for wildlife. On the other hand, slightly more than 80% of Kenya remains in a natural state. Tanzania, a country with the world’s largest population of African lions (Panthera leo) and one of the largest populations of African elephants (Loxodonta africana) is roughly 1/3rd converted —> Read More