Application of Geomorphic Principles to Environmental Management in Semiarid Regions

摘要

In many valleys of the semiarid West valley floors are either flat and vegetated without a channel, or they are gullied. Using previously collected data from the Piceance Creek area of western Colorado, it is possible to identify a valley-slope threshold above which, for a given drainage area, gullying is probable. Below this valley-slope threshold the valley floors are stable; above it they are susceptible to gullying. When the relations and techniques developed in western Colorado were applied to the Chalk Bluffs area of northeastern Colorado, it was determined that valley width was also a significant factor determining valley stability, and a ratio of valley slope to valley width could be used to identify at a given drainage area a threshold zone of valley floor instability.