Terra Nova, 00, 000–000, 2010
Bedrock canyons are most likely to be present in the upper and middle portions of river systems. Process domains, which are spatially identifiable areas characterized by distinct suites of geomorphic processes that govern sediment dynamics, provide a conceptual framework for understanding the input, storage and transport of unconsolidated material along rivers in bedrock canyons. This article introduces and briefly illustrates how process domains can be used to develop a first-order categorization of spatial variation in sediment dynamics at the catchment scale using topographic maps or digital elevation models. Process domains distinguished using parameters of valley geometry readily obtainable from topographic data (e.g. gradient, ratio of channel width to valley-bottom width) effectively delineate steep, narrow canyon segments closely coupled to adjacent hillslopes and shallower, wider canyon segments with greater alluvial storage. The Poudre River in Colorado, USA, provides an example of the delineation of process domains and of the implications of these delineations for understanding sediment dynamics.