Letters

摘要

Read the somewhat romantic article on stream restoration in your August issue ("Entering the Mainstream") with raised eyebrows. As one who has worked in stream slope instead of using the steps. Engineers of earlier generations put them there for a reason and knew what they were doing. Streams through subdivisions and urban areas are fine, but there must be separate diversion structures for high floods, a design rejected by ! some geomorphologists who veer on the dogmatic side. Bushy trees and vegetation are great, but if placed in a stream they will greatly raise the Manning coefficient value, which measures the resistance of the bed of a channel to the flow of water in it, causing increasing depth of flooding.