From landform description to processes
After studying at the College of Wooster, Strahler pursued graduate work at Columbia. His early subjects included Arizona landslides and Appalachian drainage. He became professor of geomorphology in 1958, served as departmental chairman in 1959–1962 and left Columbia in 1968 to write full time.
References: [1]
How landforms change
Robert Horton’s 1945 work on rivers helped turn his attention toward measurable processes. Strahler’s 1950 work statistically related channel gradient to hillslope form; his 1952 Dynamic Basis of Geomorphology emphasized physical and chemical processes, connecting geomorphology with hydrology, hydraulics and soil mechanics.
References: [1]
What stream order describes
In his modification of Horton’s system, headwater streams begin at first order. Equal-order channels produce a higher order when they join; a lower-order tributary does not increase the receiving channel’s order. This describes branching position within a network rather than directly measuring the size of any two rivers.
Methods and earth-science education
Strahler encouraged students to acquire statistical, engineering and hydrological knowledge relevant to erosion and channel stability. His books ranged across physical geography, geology, plate tectonics and scientific method, bringing process-based and interdisciplinary explanations to a broad readership.
References: [1]