A number of factors affect the movement of surface water in water bodies such as rivers and streams. These include wind, channel characteristics, discharge, type of obstructions, etc. Wind creates flow currents that move water. We can see the effect of wind on still water in the form of ripples, etc. A number of channel characteristics including bed slope, shape, roughness, etc. affect the flow and subsequently the surface water. Higher bed slope or more channel gradient causes steep drops and faster velocities, as compared to gentler slopes. Higher velocities will cause erosion of the bed and banks, while slow velocities will cause sedimentation of suspended particles. Higher channel roughness reduces the flow velocity. Any obstruction in the path of the water (such as vegetation, sedimentation, etc.) will cause the flow to slow down or be split into streams.
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