Meandering Rivers
Meandering rivers are a common feature of the Murray River, where the river curves around constantly creating a winding snake like figure when looked at from above. A primary factor for the cause of meandering is due to a variance of flow on the river, where one side flows faster than the other, eroding one bank (the faster side) and depositing sediments on the other (slower) side (Rutherford & Kenyon, 2005). The side of faster flow increases stress on the bends of rivers, leading to erosion. This eroded material (full of sediments) gets transported down the river and deposited in areas of slow flow, which eventually builds up and creates sandy beaches on the inside banks. The more erosion on the banks creates larger meanders. Erosion on the outside occurs at the same rate as the deposition of material, creating deep cuts into the floodplain and increasing deposits. (Rutherford, 1990, p20).
Figure F shows the progression from a straight, fast flowing river to a slower, meandering stream. A common cause for a progression from the straight river to meandering river is due to obstacles in the rivers path (for example, ‘roller eddies,’ which is water constantly tumbling over itself). Eddies can cause deep or shallow points in the river bed, which results in more water flowing over this depression at a fast rate. Fast water flowing can then erode sides of the stream, creating and picking up sediment that is deposited in areas of slower flow. (Rutherford, 1990, p20).