![]() ![]() The bank is eroded by various processes, the most important of which is undercutting low on the bank and collapse of large masses into the channel. ![]() On the outer, or concave, side of the meander bend is a steep bank or cliff, often called a cut bank, of consolidated or semiconsolidated sediment that is eroded during strong flows. Sediment is gradually accreted to the point-bar surface, causing the point bar to shift laterally. This sand body, called a point bar, lies everywhere below bank-full stage and is inundated by floods. On the inner, or convex, side of the meander bend is a fairly smooth and largely non-vegetated body of sand, sloping gently downward toward the center of the channel. Elements of the plan-view features of a meandering river The narrow part of the meander bend, between adjacent reaches of the channel above and below the bend, is called the meander neck. One can also think about a radius of curvature in the bend, but that’s likely to vary from point to point in the bend. The meander bends or meander loops are never perfectly regular, but they are often described as if they were (Figure 5-37), in terms of wavelength and amplitude. Figure 5-36 shows most of the elements of a meandering river system. First of all, keep in mind that the tendencies toward meandering and braiding are complementary rather than mutually exclusive, in the sense that many rivers show elements of both at the same time and within the same reach.įirst, some descriptive stuff on the geometry of meandering rivers. The two most characteristic plan patterns assumed by rivers are meandering and braided. ![]()
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