![]() As you saw in Figure 13.14, when a stream flows around a corner, the water on the outside has farther to go and tends to flow faster. Ī stream that occupies a wide, flat flood plain with a low gradient typically carries only sand-sized and finer sediments and develops a sinuous flow pattern. Figure 13.20 The braided Coldwater River, Mt. Helens in Washington State is a good example of this (Figure 13.20). ![]() One such environment is in volcanic regions, where explosive eruptions produce large amounts of unconsolidated material that gets washed into streams. īraided streams can develop anywhere there is more sediment than a stream is able to transport. Figure 13.19 The braided channel of the Kicking Horse River at Field, B.C. The youthful streams have high sediment loads, and when they flow into the lower-gradient glacial valleys where the velocity isn’t high enough to carry all of the sediment, braided patterns develop, characterized by a series of narrow channels separated by gravel bars (Figure 13.19). In mountainous terrain, such as that in western Alberta and B.C., steep youthful streams typically flow into wide and relatively low-gradient U-shaped glaciated valleys. This stream has a step-pool morphology and a deep bedrock channel. Figure 13.18 The Cascade Falls area of the Kettle River, near Christina Lake, B.C. They also have steep gradients and steep and narrow V-shaped valleys - in some cases steep enough to be called canyons. As shown in Figures 13.1 and 13.18, youthful streams commonly have a step-pool morphology, meaning that the stream consists of a series of pools connected by rapids and waterfalls. ![]() Youthful streams that are actively down-cutting their channels tend to be relatively straight and are typically ungraded (meaning that rapids and falls are common). The cycle of erosion has some influence on the nature of a stream, but there are several other factors that are important. Stream channels can be straight or curved, deep and slow, or rapid and choked with coarse sediments. ![]()
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