RIVER CHANGES IN RIVER LANDSCAPES

Upland River Landforms

steep V-shaped valleys, interlocking spurs, waterfalls, and gorges, formed by erosion, weathering, and mass movement.

Long Profile of Upland Rivers

In upland areas, the long profile is steep, causing rivers to flow fast and erode the river bed through hydraulic action and abrasion.

Interlocking Spurs Formation

Interlocking spurs are formed where the river swings from side to side.

Waterfalls Formation

Waterfalls occur where hard rock is more resistant to erosion than softer rock below, leading to the formation of a plunge pool and upstream retreat of the waterfall.

Effects of Lowland on River

When a river leaves the upland and enters lowland, the channel becomes wider and deeper, increasing velocity and discharge.

Valley Cross-Section in Lowland Areas

The valley cross-section in lowland areas is wide and flatter, often with a floodplain occupying the floor.

Lateral Erosion

In lowland courses, lateral erosion occurs where the river wears away the sides of the channel, especially in meanders.

Deposition in River Systems

Deposition occurs when the river loses energy, leading to the deposit of materials on the floodplain.

Levees Formation

Levees are formed by the largest amount of deposition on the banks of the channel, building up to a greater height than the rest of the floodplain.

Effect of River Velocity on Channel

Every time the river leaves its channel, the velocity decreases, affecting the potential for erosion and deposition.