William Morris Davis

William Morris Davis developed the 'geographical cycle,' also known as the erosion cycle or geomorphic cycle, which describes how landscapes evolve through stages he called youth, maturity, and old age. According to Davis, landscapes begin with a rapid uplift of land, followed by gradual erosion by rivers that eventually reduce the terrain to a flat low-relief surface he termed a peneplain. This model dominated geomorphological thinking for decades in the early 20th century.

William Morris Davis lived from 1850 to 1934 and spent much of his career at Harvard University, where he taught geology and physical geography. He was a founding member of the Association of American Geographers in 1904. His most productive period of writing on landscape evolution spanned the late 1880s through the early 1900s.

Davis's cycle of erosion is largely considered outdated as a comprehensive model, having been superseded by modern plate tectonics and process-based geomorphology. His assumption of brief, rapid uplift followed by prolonged erosion does not account for the continuous tectonic activity understood today. However, his systematic approach to landscape study laid important groundwork for the field of geomorphology.

Beyond the erosion cycle, Davis was instrumental in establishing physical geography as an academic discipline in the United States. He helped found the Association of American Geographers in 1904 and served as its president. His teaching methods and textbook writing influenced how geography was taught in American universities for much of the early 20th century.