The upper course is typified by v-shaped valleys. The river usually occupiesmost of the narrow valley floor. Vertical erosion creates the v-shaped valleys.
Mostly verticle erosion
- hydraulic and attrition
Mainly large boulders
Uneven, steep river bed, rapids, waterfalls,
The middle course is typified by the valley becoming wider. This is due to the increase in lateral erosion. Flood plains are common.
Lateral erosion begins, verticle erosion reduces,
mostly attrition with
Traction & suspendedload increases. Somesolution.
Deposition on slip off slopes.
small flood plain,
Erosion limited mainlyto lateral erosion on the outside of meanders
Small bed load (gravel,sand and some pebbles). Most material transported in suspension.
Mostly small particlesdeposited. Levées andslip off slopes formed.
The lower course of the river tends to be very wide. Large scale depositionoccurs here due to the reduced competence of a river. This part of the river
can be tidal. Rivers tend to carry a large amount of sediment at this stage.