Quantitative/dynamic geomorphology at Columbia 1945-60: a retrospective

Abstract

In the late 1940s, a graduate programme of quantitative/dynamic geomorphology largely replaced a qualitative/descriptive programme in the Department of Geology of Columbia University. Although the new paradigm had deep roots in earlier works by G. K. Gilbert, R. A. Bagnold, and others, its modern form was defined by Horton's seminal hydrophysical paper of 1945. At Columbia, two pervasive underlying concepts of geomorphic systems were stressed: a) a reductionistic dynamic analysis emphasizing categories of stress and strain; b) a synthesizing organization into natural open systems of energy and matter. Quantitative studies of fluvial systems carried out by graduate students and staff at Columbia in the early 1950s included restatement and field testing of Horton's laws of stream networks, along with improvements in stream-segment ordering and drainage density determination and in hypsometric and slope analysis. Mathematical statistics and dimensional analysis were applied to all map and field data. Morphometric parameters were related functionally to influencing variables of climate, vegetation, soils, lithology, and rock structure. Columbia research in the late 1950s introduced correlations of morphometric elements with hydrologic factors of rainfall intensity, infiltration, and runoff intensity.