Straight channels are the first of a simple three part classification by early geomorphologists, as reported by Leopold, Wolman and Miller (1957) and Schumm (1977).
These images show the oblique view and cross sectional view of a relatively straight channel. The oblique view reveals the relatively steep Valley slope associated with this natural Stream type. Many human constructed channels are straight and without step-pool sequences, thereby increasing the efficiency of moving flood waters from the area, but likely causing downstream scour due to excessive energy and shear forces. Often Streams of this straight class are in the headwater areas, and dissipate hydraulic potential energy through a series of high friction steps and scour pools. Straight channels are considered relatively stable.
Image courtesy of Rosgen