CHAPTER 3
FUNDAMENTALS OF FLUVIAL GEOMORPHOLOGY
AND CHANNEL PROCESSES
3.1
FLUVIAL GEOMORPHOLOGY
Webster's New World Dictionary defines fluvial as: of, found in, or produced by a river or
rivers. The same reference defines morphology as: any scientific study of form and structure, as in
physical geography, etc. With a little guess work, we can correctly extrapolate that fluvial geomorphology
is the study of the form and structure of the surface of the earth (geo) as affected by flowing water. Another
definition, although given in jest, may be the one most remembered after this next section. Geomorphology
is the triumph of terminology over common sense. An equally important term is the fluvial system.
A system is an arrangement of things to form a whole. The primary goal on which we want to focus in this
section is that you are working with a system and the complete system must be considered.
3.1.1
BASIC CONCEPTS
Six basic concepts that should be considered in working with watersheds and rivers are: 1) the
river is only part of a system, 2) the system is dynamic, 3) the system behaves with complexity, 4)
geomorphic thresholds exist, and when exceeded, can result in abrupt changes, 5) geomorphic analyses
provide a historical prospective and we must be aware of the time scale, and 6) the scale of the stream must
be considered. Is the stream a small, mountain meadow trout stream, or is it the Mississippi River?
3.1.1.1 The Fluvial System
Schumm (1977) provides an idealized sketch of a fluvial system (Figure 3.1). The parts are
referred to as:
Zone 1 - the upper portion of the system that is the watershed or drainage basin; this portion of
the system functions as the sediment supply.
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