Theory question 205
Environmental Hazards and Conservation(a) With the aid of diagrams, describe the characteristics of any two of the following features: (i) meanders; (ii) flood plain; (iii) braided stream.
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Meanders: loops or bends in the river's middle and lower course; outer (concave) bank is eroded and steep (river cliff); inner (convex) bank has deposition (slip-off slope, point bar); swing across a wide valley floor; may be cut off to form ox-bow lakes. Diagram of a winding channel with cross-section.
Flood plain: flat, wide plain of alluvium on both sides of a river in its lower course; built up by deposits when the river floods; fertile soils; may have levees, ox-bow lakes and swamps; coarse material dropped near the river, fine further away. Diagram.
Braided stream: river split into many small channels that divide and rejoin around sandbars or islands of deposits; occurs where the river carries a heavy load and loses speed (gentle gradient, seasonal flow); channels shift often. Diagram.
Each description needs a labelled diagram.