Two longitudinal profile segments of different concavity in ephemeral streams heading in the mountains of southeastern Arizona are related to the longitudinal variation of drainage area (A), bed-material size (Dmm), and channel width: depth ratio (W/D). These parameters approximate discharge, sediment load, and roughness, which have been found to control stream profiles in other regions, but were unavailable for this ephemeral-stream study.

Inclusion of basin relief (R) and lithology allowed development of statistically significant equations for both segments of streams draining granitic and sedimentary terrains:

Sedimentary concave:  
Sedimentary straight:  
Granitic concave:  
Granitic straight:  

Profiles of streams in two additional mountain ranges were predicted from the equations with an accuracy within the limits of accuracy of the field and map measurements. Precipitation-elevation relations have no apparent effect on the accuracy of the predictions or on stream-profile concavity.

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