abstract:In geometry, a hypersurface is a generalization of the concept of hyperplane. Suppose an enveloping manifold M has n dimensions; then any submanifold of M of n − 1 dimensions is a hypersurface.
Drylands, which range from "dry sub-humid" to "hyper-arid" regions, make up more than 40 percent of the world's land surface and are home to two billion people.