Alluvial fan geomorphic systems : the Riding Mountain Escarpment model

Abstract

This study investigates the relationships between watershed morphology, stream hydrology and the parameters which represent the alluvial fans located at the base of the Riding Mountain Escarpment. A partial synthetic systems model has been used in the first part of this study to suggest theoretical linkages between selected watershed morphometric parameters and the alluvial fan slope. Later this general systems model was expanded to include several variables considered to be representative of the stream subsystem. Initially, the variables were examined separately, employing simple regression and correlation techniques. Later they were collapsed lnto two theoretically independent variables (catchment area and unit area effective fan building discharge), and subjected to stepwise multiple regression techniques. The resulting mathematical models support the primary assumption of systematic equilibrium. Since this is the case, the alluvial fan geomorphic systems operating on the eastern slopes of Riding Mountain are considered to be in a state of dynamic equillibrium. Further examination of the multiple regression models, indicates that the watershed area is the dominant component of these systems, while specified stream discharge variables, associated with stream competence, are less significant.