V

1GG 2GG 3GG

Channel distance

K- Points of channel erosion (energy dissipation)

Figure 1 Example of some physical changes that occur with channelization. After channelization, the channel distance between two points is decreased, but the elevation remains the same. With the increased slope and reduction of channel bends, the potential energy of the flowing water switches from a lateral transfer of energy and sideways movement of the channel, to a downward erosional pattern and deepening of the river channel.

major source of nutrient exchange. Autotrophic microbial assemblages can be altered by reductions in light avail ability caused by increased turbidity, and loss of shade due to riparian vegetation reduction. Reductions in allocthonous carbon from riparian vegetation, changes in substrata composition (e.g., hard and stable to soft and silty), and changes in current velocity can alter the entire benthic community.

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