Stream Characteristics and Physical Features
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.
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.
Reprinted from Stream Connections with permission of Alberta