ABSTRACT
This part introduction presents an overview of the key concepts presents in the subsequent chapters. This part shows the other side of the erosion problem—siltation. Whenever soil or rock materials have been removed from the land, the resulting debris must ultimately be deposited elsewhere, causing sedimentation. Carl B. Brown groups the sediment problems into four categories: suspended-sediment concentration in water; in natural stream channels, improved river channels, and harbors, floodways, ditches, and canals; on land, improvements, and habitats; and in reservoirs. The US Department of Agriculture maintains a surveillance service for sedimentation in reservoirs that contains data grouped according to the 79 drainage areas of the United States. In somewhat like manner, the US Geological Survey maintains observation programs for wells and stream gaging stations and various sediment-monitoring stations in rivers. Siltation in reservoirs behind dams often has a deleterious effect on channels downstream.
