Lesson video

Hi, geographers.

My name's Mrs. Homigo.

I'm really looking forward to teaching you today.

I hope you're going to enjoy the lesson and learn lots.

Let's get started.

Today's lesson looks at the distinctive landscapes in the UK and how they've been created.

And by the end of the lesson, you'll be able to explain how distinctive upland and lowland landscapes result from physical processes and human activity.

There are five key words for today's lesson: weathering, which is the breakdown or disintegration of rocks at or near the Earth's surface; erosion, the process where material is worn away and removed by the action of rivers, wind, ice and waves; slope processes, processes that move material down slope due to gravity; climate, the long-term average of weather over a 30-year period; and human activity, actions like farming, forestry, and building that alter the landscapes.

Today's lesson has two learning cycles.

The first one looks at physical processes, creating distinctive landscapes and the second looks at human activities creating distinctive landscapes.

Let's get started now on our first learning cycle.

So a physical process is something natural that changes the shape of the landscape, and these processes work together to shape and create distinctive upland and lowland landscapes that you'll be familiar with across the UK.

The processes that we're talking about here are weathering, erosion, and that might be by rivers, waves, wind or ice, and slope processes.

We must remember though that physical factors such as seasonal or long-term changes in the climate will influence the scale of these physical processes.

Let's look first at weathering.

Weathering breaks down the rocks in situ, so where they're found, it weakens the structure and prepares the rock for potential future erosion.

Physical weathering, particularly freeze-thaw, is common in colder upland areas in the UK.

Physical weathering takes place when water enters cracks in the rocks.

As it enters the cracks, it freezes and expands.

This process can be repeated many, many times.

And in doing so, it will fracture the rock weakening it.

Freeze-thaw weathering is a key process in developing the jagged mountain peaks and squeeze slopes that we've found in upland areas in the UK.

For example, the Lake District.

This image here shows some of the distinctive rocky peaks that are found in the Lake District that are shaped by freeze-thaw weathering.

Chemical weathering is when rocks are broken down by chemical reactions and it creates distinctive limestone landscapes.

The reason it happens in limestone areas is that rainwater is slightly acidic due to the dissolved carbon dioxide.

Limestone is mostly made of calcium carbonate, which reacts with the acidic rainwater.

It forms calcium bicarbonate, which is soluble in water.

And this process creates features like sink holes, caves, and limestone pavements.

Here is an image of the limestone pavements found in the Yorkshire Dales and the Peak District.

Very distinctive landform created by this chemical weathering.

Seasonal variations in the climate will influence these physical processes and this will take place in both upland and lowland areas.

In the UK, upland areas like the Lake District, the climate is cold and wet.

And we get more frequent freeze-thaw weathering.

This breaks up the rock and contributes, as we've said, to the jagged, rugged landscape.

Whereas the lowland areas usually have a milder climate, with fewer temperatures changes around freezing, so therefore we get less freeze-thaw weathering, which contributes to the smoother, more gentle landscapes that we find here.

And by looking at those two images, you can see the contrast in the two locations.

Let's move now to erosion.

Erosion is the process where rocks and soil are worn away and removed by the action of rivers, wind, ice, and waves.

This image, as we've seen before, is that the Lake District.

And the distinctive features found in the Lake District have been shaped by glacial erosion.

So the UK's upland landscape contains many distinctive landforms that are a result of weathering and river erosion and/or glacial erosion.

The image on the left shows a very distinct V-shaped valley.

Rivers have cut down into the land through vertical erosion to create that V-shaped valley.

And where we get different areas of geology next to each other, we get waterfalls and gorgeous forming as well.

The image on the right shows the enormous erosive power of glacier, which have changed these V-shaped river valleys into dramatic U-shaped valleys during the Ice Ages as they moved through them and eroded the valley sides in bottom.

In lowland areas, river erosion and deposition also has an impact shaping the landscapes to form wide valleys with gentle slopes and broad floodplains.

The sedimentary rock that is found in lowland regions is also more easily eroded, therefore we get flatter and more open landscapes.

Quick check for you now.

True or false? Weathering and erosion are the same process.

Pause the video and make your decision.

See if you can justify your decision.

Come back when you are ready.

I hope your answer was false and your reasons similar to this one.

Weathering is the breakdown of rocks in situ, for example, through physical and chemical means.

Erosion is where material is worn away and removed from one place by agents such as water, wind or ice.

The material that is eroded has often been weathered first, so the processes do work together, but they're not the same.

Well done.

As glaciers retreated at the end of the last Ice Age, meltwater reshaped many lowland landscapes.

The powerful meltwater rivers carried a large amounts of sediment and they were very errosive.

They saw deepening of valleys, the forming of steep sided gorges as they cut into the rock, and the formation of river terraces as they eroded down into the glacial sediment as the water retreated.

They also picked up and then deposited large amounts of glacial sediment and they reworked glacial features like rains carving out new river channels.

This image here is of the terminus of the Fox Glacier in New Zealand showing a meltwater stream forming as the glacier retreats.

Slope processes are gravity driven movements that gradually shape and change landscapes.

We can see here an image showing soil creep.

Now this is the slow downward movement of slope on gentle slopes.

This image here shows slumping, which occurs when saturated soil lies on top of a weak rock and they slip down a curved surface.

This often happens after heavy rainfall.

And this shows a landslide, which is the rapid movement of rock or earth downhill.

In lowland areas, slope processes like soil creep and slumping cause the gradual movement of material downhill.

And this image shows how the profile slowly changes and it can create these very distinct step-like terracettes that we see on grass covered slopes.

In upland areas of the UK, slope processes create distinctive piles of loose broken rock fragments at the bottom of slopes called scree.

And this image here is a Borrowdale in the Lake District.

Slopes may also have scars caused by landslides and large boulders and rocks that have fallen down the slope as rock falls.

Check for you now.

Which of these distinctive landscapes has been the most influenced by chemical weathering? Pause the video and come back when you've made your decision.

I hope you identified it as B.

This image here shows us the limestone pavements of the Peak District in the Yorkshire Dales.

Now onto your first task for today's lesson.

Can you fill in the diagram to explain how climate affects physical processes and landscapes? Let's talk through the first one together.

So the climate factor.

Cold temperatures during an Ice Age.

The physical process that takes place is glacial erosion.

Now what impact does that have on the landscape? The second climate factor is precipitation, and the third is temperature regularly dropping below a zero degree Celsius.

Pause the video and come back when you've had a go.

Your answers may have looked something like this.

So cold temperatures during an Ice Age leads to glacial erosion.

The impact this has that it creates distinct landscapes such as U-shaped valleys due to enormous power of glacial erosion.

The second climate factor is precipitation.

This can lead to chemical weathering and it creates distinctive landscapes in limestone regions featuring limestone pavements, sink holes, and caves.

And the third climate factor is the temperature regularly dropping below zero degrees Celsius, which leads to physical weathering, particularly freeze-thaw weathering.

This creates distinctive upland landscapes of jagged rocks and scree.

Well done if you've managed to fill out your diagram like this.

Let's move now to our second learning cycle and think about the human activities creating distinctive landscapes.

So human activities can have a significant impact on landscapes by altering vegetation cover and impacting on natural processes such as erosion and slope processes.

We have three activities here, agriculture, forestry, and settlements.

And we're going to think about how each of those has an impact on the landscape.

So humans have modified landscapes extensively for agriculture over thousands of years.

Arable farming is most extensive in lowland UK, especially the drier east.

In order for that to take place, we have to clear the natural vegetation.

This means that we get large level fields that are created for crop growth.

This has an impact on natural drainage patterns changed with the drains and the ditches to support the farming.

And so as a result, the landscape becomes more uniform and managed.

And we can see it there that image of a very managed farm environment.

Pastoral farming is the most common in the wetter west of the UK and in upland areas.

And this is because the soil is much poorer quality and it's not suitable for arable farming in the same way.

The sheep will graze on the steep thin soiled slopes.

And so in doing that, natural vegetation is reduced or removed.

The soil will become compacted by their hooves.

And this will lead to more surface runoff, and this can increase soil erosion.

Check for you now.

Can you suggest a way in which human activity has affected the landscape shown in this OS map extract? Pause the video and come back when you've had a think.

Your answers might have included forestry, building a reservoir, constructing roads and paths, building settlements and mining.

So well done if you correctly identified one of those human activities.

So we can see here that this map extract shows how human activities have actually changed this landscape in variety of different ways.

Forestry also alters the natural landscape through the planting and fell of trees.

This image is an example of a commercial plantation in the Scottish Highlands.

They use the fast growing non-native conifers in these upland areas.

These trees do in fact stabilise the soils and so reduce soil erosion.

However, they reduce biodiversity and it changes the landscape.

Forestry fails trees to sell the timber, and this leads to areas of the landscape being deforested and then replanted.

So deforestation is a significant landscape change and it can happen rapidly.

The impacts it has is there is a loss of vegetation, increased soil erosion as it is no longer protected by the trees, more surface runoff and flooding, and the deforest slopes change the landscape.

Some urban areas have almost entirely replaced the natural landscape.

This photo here shows an example of that in the Thames Valley, with the River Thames flowing through London.

The natural floodplain has almost entirely been built on.

So the land is cleared for housing, roads and infrastructure, which removes all natural vegetation.

It has a visual impact.

The natural view views are replaced with buildings and artificial features.

Wildlife habitats are lost or fragmented, so broken up, and so biodiversity is reduced.

River courses may be straightened or altered for flood protection or urban development.

And soil is covered over by concrete and tarmac, which reduces infiltration and increases surface runoff and so the flood risk.

However, other settlements have smaller impacts on natural processes or they are trying to restore the natural features to their landscapes.

Green spaces within settlements can enhance biodiversity.

Planning policies in conservation areas, limit development that could degrade the landscape.

So for example, national parks.

The restoration of brownfield sites can improve degraded land and reduce pressure to expand settlements.

And river courses upstream of some settlements are being rewilded for more sustainable flood management.

Let's have a check now.

Which two of the following are ways in which human activities result in distinctive landscapes? A, land is cleared of forest for farming; slope processes produce terraces; soil is covered in tarmac and paving; valleys were eroded by glassier during Ice Ages.

Pause the video and come back when you've decided.

I hope you said land is cleared of forest for farming and soil is covered in tarmac and paving.

Task B for you.

The first question, describe two ways in which human activities have changed the natural landscape shown in this photo.

Pause the video and have a go.

Second question is using evidence from the map extract, suggest two ways in which this landscape has resulted from human activity.

Pause the video and come back when you've had a go.

For your first answer, describing the two ways in which human activities have changed the natural landscape in this photo.

You may have put settlement development.

A town with many houses, roads, and a church is clearly visible.

The river in the photo may have been managed to reduce flooding in the town.

And agriculture, the vegetation on the lower parts of the surrounding hills has been cleared to make fields for crops or pasture.

And for the second question you might have put, there are many buildings labelled Fm, which stands for farm.

So this is a farming landscape.

There is a river on the map, but it has very straight edges.

They're also very straight drainage channels.

Probably the drainage of the landscape has been changed by human activity.

Well done if your answers to those two questions were similar.

Let's have a look now at a summary of today's lesson.

Physical processes have naturally shaped the UK's distinctive upland and lowland landscapes over time.

Seasonal and long-term changes in the climate can influence the scale of these physical processes.

Some of the UK's distinctive landscapes are the result of human activity such as agriculture, forestry, and settlement.

And human activities may intensify or reduce the effects of physical processes.

For example, deforestation increases soil erosion on the slopes.

Well done today.

I hope you feel more confident now in describing the physical processes and the human activities that create distinctive landscapes in the UK.

I look forward to seeing you again soon.