River Pathways:
Stream Characteristics and Physical Features
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Most rivers in Alberta originate from the glaciers and spring snowmelt in the
Rocky Mountains of western Alberta. Many small streams or tributaries come together to form a larger one. The number of tributaries entering a particular river decreases as you move downstream.
As a stream or river flows away from the mountains, it will take on a variety of physical characteristics. Often, sharp bends or loops called meanders will form. A stream that consistently turns and winds its way through the land is known as a meandering stream.
Erosion occurs on the outside bank of a meander curve, where the water flow is fastest.
Sediment deposition takes place on the inside of a curve, where the water flows more slowly. These continuous deposits of sediment create a point bar or build up of sand and gravel. Water on a point bar is usually quite shallow. Large rivers tend not to meander very much because the great force of their flow erodes a straight channel.
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Erosion slowly changes a river's appearance. For example, sometimes a meander can be so sharply "looped" that the flow of water can erode a new path, avoiding the loop altogether.
This can result in a "donut" or "bow" shaped body of water that is separated from the river, and is called an oxbow lake. The next time you canoe down a river, drive over a bridge, or fly in a plane, see if you can spot some of these river characteristics.