Physical Revision - Rivers and Hazards

What is a watershed?

• A storage area for floodwater

• The area of land a river flows through

• The boundary between two drainage basins

• A lowland area where rivers meet

As a river flows from source to mouth, its long profile becomes:

• Steeper

• Flatter

• More irregular

• More elevated

Why is vertical erosion dominant in the upper course of a river?

• Due to strong tidal forces

• Because the river has a high load

• The gradient is steep

• The channel is wide and deep

V-shaped valleys are formed by:

• Abrasion in the lower course

• Hydraulic action in the middle course

• Vertical erosion and weathering

• Deposition on the river banks

Which of the following landforms is found in the upper course of the River Tees?

• Ox-bow lake

• Meander

• High Force waterfall

• Floodplain

High Force waterfall was formed by:

• The collapse of a levee

• A sudden tectonic uplift

• River erosion over hard rock (Whinstone) and soft rock (limestone)

• Sea erosion at the estuary

Interlocking spurs form when:

• Rivers meander through flat land

• Soft rock is quickly eroded

• Rivers cut down into resistant rock around hills

• Flooding deposits material on bends

Lateral erosion in the middle course causes:

• Waterfalls

• Narrow valleys

• Widening of the river channel

• Steep-sided gorges

Meanders form due to:

• Ice movement

• The river losing velocity

• Erosion on the inside of bends

• Erosion on the outside and deposition on the inside

Ox-bow lakes are created when:

• Water flows backwards from the sea

• Floodwaters breach a levee

• The neck of the meander is cut off

• A waterfall collapses