Geomorphology of Desert Environments

In popular concept, a desert should be hot, barren, and, preferably, sandy. In reality, many deserts are few, or none of these things. Most deserts are, however, areas of aridity, and it is upon this property that the scientific definition of deserts has generally hinged. Even so, providing an acceptable measure of aridity upon which to base a definition of desert areas has not been straightforward, and several attempts based upon a variety of geomorphic, climatic, and/or vegetational indices of aridity have been made to identify the world distribution of deserts.