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The terms river morphology and its synonym stream morphology are used to describe the shapes of river channels and how they change in shape and direction over time. The morphology of a river channel is a function of a number of processes and environmental conditions, including the composition and erodibility of the bed and banks (e.g., sand, clay, bedrock); erosion comes from the power and ...
The graph takes sediment particle size and water velocity into account. [2] The upper curve shows the critical erosion velocity in cm/s as a function of particle size in mm, while the lower curve shows the deposition velocity as a function of particle size. Note that the axes are logarithmic.
In the cycle of erosion model, knickpoints advance one cycle upstream, or inland, replacing an older cycle. [1] A knickpoint that occurs at the head (furthest upstream extent) of a channel is called a headcut. [2] Headcuts resulting in headward erosion are hallmarks of unstable expanding drainage features such as actively eroding gullies. [3]
A region can be uplifted at any stage. This lowers the base level and streams begin active downward erosion again. Dynamic rejuvenation may be caused by the epeirogenic uplift of a land mass. Warping or faulting of a drainage basin will steepen the stream gradient followed by the downcutting. The effect of seaward tilting can be felt ...
Rectangular drainage develops on rocks that are of approximately uniform resistance to erosion, but which have two directions of jointing at approximately right angles or 90 degrees. The joints are usually less resistant to erosion than the bulk rock so erosion tends to preferentially open the joints and streams eventually develop along the joints.
The faster the water in a river channel, the better it is able to pick up greater amounts of sediment, and larger pieces of sediment, which increases the river's bed load. [4] Over a long enough period of time, the combination of deposition along point bars, and erosion along cut banks can lead to the formation of an oxbow lake .
where Q is the water discharge of the river [m 3 /s], and W is the width of the river channel [m]. Relative differences in long-term erodibility can be estimated by quantifying the erosion response under similar climatic and topographic conditions with different rock lithology. [10]
The color of a water sample can be reported as: Apparent color is the color of a body of water being reflected from the surface of the water, and consists of color from both dissolved and suspended components. Apparent color may also be changed by variations in sky color or the reflection of nearby vegetation.