River Processes

• There are 4 types of erosion
• Hydraulic action is the sheer power of the water as it smashes against the river banks. Air becomes trapped in the cracks of the river bank and bed, causing the rock to break apart
• Abrasion is when pebbles grain along the river bank and bed in a sand papering effect
• Attrition is when rocks that the river is carrying knock against each other and they break apart to become smaller and more rounded
• Solution is when the river dissolves certain types of rock
• There are 4 types of transportation
• Traction is when large heavy pebbles are rolled along the river bed. This is common near the source of the river as the load is larger
• Suspension is when lighter sediment is suspended within the water, most common near the mouth of the river
• Solution is the transport of dissolved chemicals. This varies along the river depending on the presence of soluble rocks
• Deposition is when the river lose energy and drops any material it has been carrying.
• Factors leading to deposition include shallow water, at the end of the rivers journey, at the rivers mouth or when the volume of water decreases
• A watershed is the high area of land forming the edge of a river basin
• The source is where the river begins
• The mouth is where the river meets the sea
• A confluence is the point 2 rivers meet
• A tributary is a small stream that joins the larger river
• The channel is where the river flows
• The upper course - where the river starts there is often an upland area. The load is large in the upper course because it hasnt been broken up by erosion
• Lower course - in the lower course the land is a lot flatter. The rivers load is fine sediment as erosion has broken down the rocks