Floods and Flood Control

Floods occur when a body of water, e.g., a stream, lake, or sea, overtops its normal channel or basin because of excessive inflow of water or geophysical or atmospheric activity. The two broad categories of floods are stream flooding and coastal flooding. Most types of floods are a very normal part of the hydrological rhythms of water bodies. In fact, many riparian and coastal systems generally depend upon cycles of flooding to maintain a healthy ecology. Human societies in coastal and riparian regions have evolved agricultural and resource extraction systems dependent upon cycles of flooding to maintain productivity and sustainable livelihoods. Since the onset of the Industrial Revolution, urbanization, and increasing populations, however, the equation between human societies and floods has changed into a largely ...