Spatially identifiable areas characterized by distinct suites of geomorphic processes. This may be on the basis of observed precedence, or involve superposition of information layers describing the distribution of causal factors (Preston in A. Lang et al., eds 2003). See J. Phillips and W. Renwick, eds (1992) and Montgomery (1999) J. Amer. Water Resources Ass. 35, 2.
Subjects: Earth Sciences and Geography.