Explain the differences in the size and shape of the material on the river bed in the upper and lower courses of a river
In the upper course load is smaller and more rounded than in the lower course because of erosional processes such as attrition and abrasion.
As a river moves through its course, because of the greater incidence of larger settlements, more supermarket shopping trolleys are likely to be found in rivers, adding to the load that has already been deposited.
In the lower course load is smaller and more rounded than in the upper course because of erosional processes such as attrition and abrasion.
In the lower course load is larger and angular because it has been eroded by processes such as attrition and abrasion.