stream erosion

This is an example of stream erosion. This is located in 

Linn County, Oregon. This stream supports 3 communities

and the erosion is constant. 

This is a picture of the different loads in a stream. These 

loads include solution. suspended, and bed. This is the 

way debris moves through streams.

  Stream erosion happens when loose sediments are moved along the bottom of a river channel creating small bed forms such as ripples and sand dunes. There are 3 types of loads in stream erosion including solution, suspension, and bed. Solution load, or dissolved, is when dissolved rock is carried in the flow. This is higher where the flow is derived from groundwater pathways. This allows water to stay in contact with rock for long periods of time. It is also higher where rock is prone to chemical weathering. The next load is Suspension. Suspension load happens with finer sediment such as clay and silt and as it flows, it does not come into contact with the bed. The clay and silt is suspended by the turbulent flow of the water. The suspended load comes from materials eroded from the surface bordering the channel and deposited in the stream plus the erosion from the channel. The third load is the bed load. The bed load is moved through the bed of the channel. The bed is transported by traction and saltation. Traction is the scooting and rolling of materials through the bed of a stream. Saltation is the movement of materials through a bounce like motion. Saltation occurs when materials  are suspended in a stream for a short distance and then fall to the bed, dislodging particles. This is a reoccurring pattern. 

   Mature streams form after excessive erosion has occurred over time. It is characterized by the sloping sides. The stream gets wider and becomes more U shaped. The stream will also become less steep which results in slower and steadier moving water. This characteristic can lead to the formation of large floodplains where water can escape if the stream somehow becomes flooded. On the other hand, a youth stream occurs when a stream is in it early stages on an uplifted landmass. These streams are very steep in formation and have an energetic flow of water. Unlike the U shape of a mature stream, youth streams are V shaped and have not formed a floodplain yet. Youth streams are also characterized by the interruption of boulders, rapids, and waterfalls on the flow of the stream. Floodplains are areas of land that are prone to flooding the surround mature streams. This is the wide, level bottom of a valley that contains a stream. These are very important areas to have because they are capable of holding water from a flooded stream. Floodplains vary on the size and depth of the valley that the stream is located in. When enough land is eroded and a mature stream is formed, this is now called a stream valley which is a depression of earth with water flowing at the lowest point. Stream valley's are characterized by the presence of floodplains.