Davis, William Morris (1850-1934)

US physical geographer who analysed landforms. In the 1890s he developed the organizing concept of a regular cycle of erosion, a theory that dominated geomorphology and physical geography for half a century.

Davis was born in Philadelphia and studied science at Harvard, where he taught 1877-1912.

Davis proposed a standard stage-by-stage life cycle for a river valley, marked by youth (steep-sided V-shaped valleys), maturity (flood-plain floors), and old age, as the river valley was imperceptibly worn down into the rolling landscape which he termed a ‘peneplain’. On occasion these developments, which Davis believed followed from the principles of Scottish geologist Charles Lyell, could be punctuated by upthrust, which would rejuvenate the river and initiate new cycles.