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41 Cards in this Set

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What is mechanical (freeze thaw) weathering

Water fills a crack or joint in a rock. Water freezes and the crack expands. This process repeats until the rock breaks away

What is chemical (acid rain) weathering

Rainwater is slightly acidic. The acid reacts with minerals in the rocks and dissolves them.

What is biological weathering

Roots grow into rock cracks and split them apart

What is mass movement

The sides of a river valley becoming less steep as material is moved from the top to the bottom

What is sliding

When gravity pulls a weakened material downwards

What is slumping

Where the river eroded the bottom of the valley slope, making it steeper. Material above then slides down as a consequence

What is traction

Large boulders being rolled along the river bed

What is saltation

Smaller pebbles being bounced along the river bed.

What is Suspension

Finer sand particles are carried along in the flow

What is Solution

Some minerals such as chalk are dissolved in the water and carried along in the flow

What’s the gradient like in the upper course and why

Steeper. Because the river eroded vertically

How do interlocking spurs form?

The river at the source is small and has limited energy. This causes the river to naturally flow from side to side, around ridges in the valley, called spurs

How do waterfalls form?

They form in the upper course where there is an increase in vertical erosion. They form where there is a layer of hard resistant rock overlying a softer, less resistant rock

How are gorges formed

Over a long time, the process of undercutting and collapse is repeated, and the waterfall retreats, forming a steep-sided gorge

What is a floodplain

A wide, flat area of land either side of a river which experiences flooding when the river tops its banks

How much sediment does the lower course carry and why

A huge amount of sediment because it’s nearing the sea

How does flooding form a floodplain?

Flooding causes the river which is carrying sediment to overflow and lose its velocity and deposit the sediment

What are levées and how are they formed

The deposition process, which takes place during flooding, continues until eventually embankments, made of larger, heavier sediment, are created besides the river

Where do meanders form?

Usually in the middle but sometimes lower course

How does a meander form?

In the middle course the width, depth, and velocity of the river all increases. This causes the river to erode sideways which starts to form bends. These bends get bigger and wider and eventually develop into a horseshoe shape

Give the five step process of the formation of an Ox-bow lake

1.) narrow neck of meander is gradually being eroded


2.) water now takes the quickest route


3.) deposition then takes place which seals off the old meander


4.) meander neck has been cut through completely


5.) Ox-bow lake left behind when meander is completely cut off

How does urbanisation cause more flooding?

Leads to less permeable surfaces

How does agriculture effect flooding?

Moves water into streams and rivers faster

How does agriculture effect flooding?

Moves water into streams and rivers faster

How does rainfall intensity effect flooding

A lot of rainfall over a short period of time prevents soil infiltration

How does geology effect flooding

Rocks like granite are impermeable so water is unable to percolate from the thin soil above

How does snow melting effect flooding

At spring time warmer temperatures will melt snow creating more water

How does drainage basin effect flooding

Steep-sided valleys or a lot of tributaries means the water enters the river system quicker

How does drainage basin effect flooding

Steep-sided valleys or a lot of tributaries means the water enters the river system quicker

All these four factors lead to what thing that effects flooding?

Excess water flows towards the river as surface run off

How does drainage basin effect flooding

Steep-sided valleys or a lot of tributaries means the water enters the river system quicker

All these four factors lead to what thing that effects flooding?

Excess water flows towards the river as surface run off

Name two pros and two cons of Dams and reservoirs (hard engineering)

👍🏻store large volumes of water until needed


👍🏻long-lasting; can be used to generate hydro-electric power


👎🏻expensive to build


👎🏻sediment can build up in reservoirs

Name a pro and two cons of channelisation

👍🏻allows water to flow more quickly away from areas of flood risk


👎🏻visually unattractive


👎🏻more water is taken downstream, increasing the flood risk to other settlements

What is the landscape impact of dams and reservoirs

The natural river valley landscape is flooded

What is the landscape impact of channelisation

Replaces the natural meanders and floodplain with an artificial channel

Give two pros and a con of floodplain zoning (soft engineering)

👍🏻reduces number of homes at risk of flooding


👍🏻allows infiltration to reduced surface run-off and flooding is reduced


👎🏻restricts the growth of settlements

Give two pros and a con of washlands (soft engineering)

👍🏻create an area for floodwater to go


👍🏻allow natural river processes such as deposition


👎🏻might limit the use of land

Describe the landscape impact of floodplain zoning

Preserves the natural floodplain

Describe the landscape impact of floodplain zoning

Preserves the natural floodplain

Describe a landscape impact of washlands

Preserves the natural floodplain landscapes in the mid and lower river courses