Sediment and Sedimentation

Water is the most effective agent of transport, even in the desert. When you think of water erosion, you probably think of erosion mainly by stream water, which is channelized. However, water also erodes when it flows over a lawn or down the street, in what is known as sheet flow. Even when water simply falls from the sky and hits Figure 1. Table of names for sedimentary particles based on grain size. Illustration by Hans & Cassidy. Courtesy of Gale Group. the ground in droplets, it erodes the surface. The less vegetation that is present, the more water erodes—as droplets, in sheets, or as channelized flow.