¶ … Stream Channel Lynn Canyon

Changes in the shape of the stream channel

The study of the canyon is best done as was in this case during the winter, spring and summer when the water levels are low and most of the features are exposed for observation and study, and also the safety of the Canyon is more assured than during the heavy rains. In autumn, there are heavy rains and also during the peak snow, the melting snow in spring results in high water levels that may ultimately obscure some of the stops that are lower in latitude.

The concentration of this section will be on the river that flows on the bed of the Lynn Canyon and the physical features it has, the direction and change of its flow as well as the evidence that exposes the ages of changes that the river has undergone in terms of the direction, force and the size.

The stream within the canyon kept shifting the channel over the years due to the presence of large boulders. In some places, the stream is observed to flow around elongated boulder ridges within the channel formed during the higher flow stages. Across the stream and up the stream, it is observed that there is a boulder surface that keeps a forest alive of 10 m trees from the east bank of the stream. Further down the stream, the river flows round an island with larger trees and the banks are a lower layer of boulders covered by a layer of sand. The forest along the stream is a mosaic of patches made up of trees of different ages. The age of each patch of trees indicates the date that this region of the stream was an active bar in the channel of Lynn Creek. The river channel is also observed to be changing its position and at times the...

This is evidenced by the variable age of tress along the stream and in particular along the floodplain (Bob T. & John C., n.d).
There is also evidence of the banks being eroded and this can be seen through the steep yet un-vegetated and the stream flows near its base and there are also trees that have fallen into the river from the bank due to under-cutting the bank. There is also lacking vegetation, meaning the river had flown through this region. The stream flow fills several channels across the floodplains. It was also observed that upstream, the river cuts a narrow canyon into the bedrock and downstream it broadens and splits as it flows through a floodplain. Upstream, the surface of the bedrock is above the creek level and Lynn Creek has only been able to cut a narrow canyon through this hard rock. Downstream, the bedrock surface is buried and here the river has cut a much broader valley in the much softer, thick sediment that overlies the bedrock. These sand and gravel sediment are visible in cliff of the Canyon mouth.

Fig. 1.0 The sketch of the Canyon. Within the Canyon, the flow of the river majorly runs between the narrow walls. This kind of concentrated flow has caused a deep pool in the gravels at the mouth of the canyon. The scouring of these pools happens mostly during floods when the energy of the river is highest. As the waters spread down stream, they lose energy and the pools tend to be generally shallower towards the downstream.

The absence of vegetation along the cliff is a clear indication of the active erosion that takes place especially during floods when the water levels rise and lap up…