Lesson video

Hello and welcome.

My name is Miss Harrison.

I'm so looking forward to learning with you today.

Today's lesson is called: Change in a named coastal landscape.

Grab everything you might need for today's lesson and let's begin our learning.

By the end of today's lesson, you will be able to use knowledge of a location to explain how physical and human processes interact to cause change at the coast.

Before we can begin this learning, we need to define the keywords that we'll be using throughout today's lesson.

The keywords we'll be using are: erosion, climate change, and coastal management.

Erosion: this is the wearing away of rocks along the coastline.

Climate change: this is the long-term shifts in temperatures and weather patterns.

Coastal management: this is the protection of coastlines from erosion and flooding through either artificial or natural methods.

Now that we've defined these keywords we can begin our learning.

The first question we're going to explore in today's lesson is what is happening at Happisburgh? Before we can begin learning what's happening at Happisburgh we need to be able to locate where Happisburgh is.

Happisburgh is a coastal village in Norfolk, a county in the east of England.

The North Sea is to the east of Happisburgh.

We know that Happisburgh is a coastal village, but this wasn't always the case.

When it was founded over a thousand years ago, there was another village separating Happisburgh from the sea.

This means that there was a village in front of Happisburgh that was closer to the sea.

However, through coastal erosion, this village no longer exists.

Historical records have shown that over 250 metres of land was lost between 1600 and 1850.

The image on the screen is of two maps, one from 1890 and the other from modern day.

As you can see in the modern day map, Happisburgh is much closer to the coast compared to the 1890s map, showing the effects of coastal erosion.

We know that Happisburgh is experiencing coastal erosion, but in fact, it is experiencing one of the fastest rates of coastal erosion within the UK with average erosion rates of two to three metres per year and sometimes even reaching up to 10 metres per year.

This is causing devastating effects on the communities living in Happisburgh.

In the last 20 years, 34 houses have been lost to coastal erosion.

This has meant people have lost their homes, their communities, and even their jobs.

Let's test our knowledge.

True or false? Happisburgh is the UK's slowest eroding coastline with rates of two to three metres gained from the sea each year.

Pause the video here whilst you decide if this statement is either true or false, and press play when you're ready to continue.

Fantastic.

This statement is false.

I would like you to explain why the statement is false.

Pause the video here and press play when you're ready to continue.

Excellent work.

The reason why the statement is false is because Happisburgh is one of the fastest eroding coastlines in the UK, with an average rate of two to three metres of coastline lost to erosion each year.

Well done if you managed to explain that correctly.

On average, how much does Happisburgh's coastline erode by each year? Is it A: one to two metres? B: two to three metres? Or C: three to five metres? Pause the video here whilst you decide which statement is correct and press play when you're ready to continue.

Excellent.

The statement that explains correctly how fast Happisburgh's coastline is eroding each year is B: two to three metres.

Well done.

The text below is explaining what is happening at Happisburgh.

I would like you to fill in the blanks using the words below.

Pause the video here whilst you attempt this task and press play when you're ready to continue.

Well done on attempting this task.

Let's check our answers.

Your text should read like this: "Happisburgh is located on the eastern coast of England in the county of Norfolk.

The village is well known for its rapid coastal erosion.

The coastline at Happisburgh is eroding at a rate of around two to three metres per year.

Over the past several decades, Happisburgh has lost approximately 34 houses to the sea due to erosion.

Fantastic.

Well done on this task.

The next question we're going to explore in this lesson is How do physical processes affect Happisburgh? Happisburgh is affected by a number of different physical processes, such as geology, direction of the waves from the North Sea, and the longshore drift.

All of these make the Happisburgh coastline vulnerable to erosion.

On the image below, we are going to label the different physical processes.

Happisburgh has a weak geology as it is made up of glacial till and is less resistant to erosion.

The direction of longshore drift is going to be important in understanding the movement of sediment at Happisburgh.

And the strong winds and maximum fetch from the northeast of the North Sea are going to play an important role in the erosion of the cliffs.

Happisburgh's cliffs are mostly made of glacial till, a mixture of broken rock, sands and clays that have been deposited by retreating ice sheets thousands of years ago, and as a result, they have a low resistance to erosion.

As you can see in the video below, the material is easily able to be broken up.

Andeep has said that judging from the video, he can see that the cliffs at Happisburgh hardly even look like rock at all.

Because of Happisburgh's weak geology, the cliffs are vulnerable to mass movement, particularly undercutting by the sea, which will lead to rockfall and saturation of clay within the till, which can lead to slumping, which will affect the coastal erosion rates.

At Happisburgh, the fetch, this is the distance the wave travels across the North Sea, creates destructive waves.

Destructive waves are high-energy waves that remove material from the coast.

The fetch reaches up to 600 to 800 kilometres for northeasterly winds and 200 to hundred kilometres for easterly winds.

This demonstrates the waves at Happisburgh have a really far distance to travel, which means they're going to pick up a lot of energy which will erode the coastline.

As you can see on the map, we have labelled the direction of these winds.

That means these winds are going to be attacking Happisburgh at all angles, which means the amount of erosion that will take place is going to be increased.

The direction of longshore drift at Happisburgh is predominantly south towards Great Yarmouth.

This means that sediment is transported north to south and it's going to reduce the size of the beach at Happisburgh.

Erosion and longshore drift are going to reduce the size of the beach at Happisburgh.

The graphic on the screen is comparing aerial images of Happisburgh's beach from 2014 to 2020.

As you can see on the graphic, the beach in 2014 is much wider than the beach in 2020, which is very narrow, and this is a result of longshore drift and continued erosion.

Let's now test our knowledge.

What is the geology of Happisburgh? Is it A: sedimentary rocks, B: glacial till, or C: igneous rocks? Pause the video here whilst you decide and press play when you're ready to continue.

Excellent.

The geology of Happisburgh is B: glacial till, which we know is less resistant to erosion.

What direction is longshore drift at Happisburgh? Is it A: southwards towards Great Yarmouth, B: westwards towards Sheringham, or C: eastwards towards Cromer? Pause the video here and press play when you're ready to check your answers.

Excellent.

Direction of longshore drift at Happisburgh is.

A: southwards towards Great Yarmouth, which is causing the beach to become shorter and narrower.

I would now like you to complete the table below on the physical processes affecting Happisburgh.

We've decided to focus on three processes: geology, destructive waves, and longshore drift.

When you're writing a description, they need to be specific to Happisburgh, and then the impact on Happisburgh again needs to be specific on how these processes have affected Happisburgh.

Pause the video here whilst you complete this task and press play when you're ready to continue.

Excellent work.

Well done for attempting this task.

Let's check our answers.

Your answers might include something like this: "Geology.

It's description: The cliffs are made of unconsolidated material like clay, sand, and silt.

An the impact it has: Cliffs at Happisburgh are easily undercut by wave action and prone to rockfall and slumping.

Destructive waves.

The description: The North Sea has a fetch of 600 to 800 kilometres for northeasterly winds and 200 to 300 kilometres for easterly winds.

Its impact: destructive waves are causing the Happisburgh coastline to retreat by two to three metres per year.

Longshore drift.

The description: Sediment is transported towards Great Yarmouth.

Impact on Happisburgh: This is reducing the size of the beach and increasing cliff erosion.

Well done if you managed to get these answers.

We're now going to explore our final question of this lesson.

How do human processes affect Happisburgh? Human processes play a significant role in the rate of coastal erosion at Happisburgh.

What processes affect Happisburgh's coastline? I would like you to pause the video here whilst you decide and press play when you'd like to check your answers.

Excellent.

Some of the human processes that affect Happisburgh's coastline are: Climate change, this is the change in weather and temperature patterns, tourism, agriculture, and coastal management.

Remember, coastal management is the protection of coastlines from erosion and flooding through either artificial or natural methods.

Happisburgh is vulnerable to the indirect effects of climate change, which is caused by human activity.

The rising sea levels can increase the likelihood of erosion and coastal flooding through storm surges.

The image on your screen is a projection of a potential risk of rising sea level at Happisburgh.

It shows the impact of one metre rise, three metre rise, and a five metre rise in sea level.

And as you can see, Happisburgh will be affected by increasing sea level rises, which will increase the rate of erosion.

Let's test our knowledge.

How has climate change affected coastal areas like Happisburgh? Is it A: decreased frequency of severe storms, B: expansion of land areas, or C: increased risk of storm surges? Pause the video here and press play when you're ready to continue.

Fantastic.

The answer is C: climate change has affected coastal areas like Happisburgh through increasing the risk of storm surges.

Happisburgh is a really popular tourist destination and because of this, the development of tourism and leisure spaces has led to increased pressure on fragile environments.

For example, increased foot traffic has damaged the vegetation that helps to stabilise the cliffs.

The weight of the caravans and infrastructure adds pressure to the cliffs, and as we know, Happisburgh's cliffs are very weak as they're made up of glacial till.

Rainwater runoff from paved areas can weaken the cliffs, which can increase the risk of landslides.

Along the Happisburgh coastline, there are many farms that you can find, and agricultural activities have reduced the stability of the cliffs.

Activities that have contributed to weakening of the cliffs, which has made them more prone to collapse are: the use of heavy machinery on the weak cliffs, the removal of natural vegetation which helps to stabilise the cliffs, and the ploughing close to the cliff edge, which is already vulnerable to many types of mass movement.

Let's test on knowledge.

True or false? Development of tourism spaces has increased the strength of cliffs and led to less coastal erosion.

Pause the video here whilst you decide if this statement is true or false and press play when you're ready to continue.

Excellent.

The answer is false.

I would like you to explain why the statement is false.

Pause the video here and press play when you're ready to continue.

Excellent.

The reason why the statement is false is: "Tourism development has weakened the cliffs and increased erosion.

The weight of caravans adds pressure, increasing the risk of slumping, and rainwater runoff from paved areas further weakens the cliff leading to landslides.

Well done if you managed to explain that correctly.

Coastal management strategies such as revetments and groynes, were in place in Happisburgh to stop the rate of erosion, but sadly, these were damaged by storms in the 1990s and have not been repaired or replaced.

With broken and no coastal management in place, the beach has become narrower due to erosion and longshore drift.

On the image on your screen, you can see the remains of revetments that have not been maintained.

The Bacton Gas Terminal, located north of Happisburgh, underwent a beach nourishment project in 2019.

Beach nourishment projects involve moving sediment from the seabed onto the coastline to make sure the beaches are wider and are less affected by erosion.

The project aimed to protect Bacton and nearby communities.

This process altered the sediment flow and actually increased the amount of sediment that reached Happisburgh and it temporarily reduced erosion rates.

However, other coastal management strategies have not been as effective in reducing coastal erosion at Happisburgh.

At Bacton and Sea Palling, they disrupted sediment flow as they trapped material that would naturally replenish Happisburgh's beach.

This resulted in Happisburgh having a sediment-starved beach, leaving the cliffs more vulnerable to erosion.

As you can see on the image, there are offshore breakwaters and groynes that have been used at Bacton and Sea Palling to stop erosion happening there, but it has increased erosion in Happisburgh.

The shoreline management plan for this stretch of coast involves a policy of managed retreat, which means that they allow the coastline to retreat naturally.

The high costs of defending the coast outweighed the benefits, and so the local council has decided that the coastline would be allowed to retreat in a controlled manner.

However, this led to a loss of homes and infrastructure in Happisburgh.

Let's test our knowledge.

How has coastal management at neighbouring villages impacted Happisburgh? A: increased tourism at Happisburgh, B: decreased the transfer of sediment to Happisburgh, or C, increased the biodiversity at Happisburgh? Pause the video here whilst you decide and press play when you're ready to continue.

Excellent.

Coastal management strategies at neighbouring villages have impacted Happisburgh through.

B: decreasing the transfer of sediment to Happisburgh.

Well done.

I would now like you to complete this question: Assess the extent to which human activities have increased coastal erosion at Happisburgh.

You will need to use specific examples in your answer that we have learned in today's lesson.

Andeep has said that he's going to write about how coastal management strategies near villages like Bacton and Sea Palling has led to more coastal erosion at Happisburgh.

And Izzy is going to talk about how caravan sites put a lot of pressure on already really fragile environments.

Pause the video here whilst you tackle this question and press play when you're ready to check your answer.

Excellent.

Let's check our answer.

This is a model answer.

It doesn't mean that your answer needs to look exactly like this, but it's just showing you examples of what your answer could include.

"One of the main human causes of increased erosion is the use of coastal management strategies in nearby areas, such as rock armoring at Bacton and the revetments at Sea Palling.

This is trapped sediment that would naturally drift towards Happisburgh, leading to a sediment-starved beach.

Without enough sediment to build up the beach, the waves directly attack the cliffs, increasing the rate of erosion.

In addition, the managed retreat policy has left Happisburgh without proper coastal defences.

The shoreline management plan decided that defending Happisburgh was not economically viable, so the area was left to erode naturally, leading to a coastline retreat of two to three metres per year.

Moreover, caravan parks near the cliff edge have also contributed to erosion.

These developments increased foot traffic, which damages the vegetation that helps stabilise the cliffs, the weight of the caravans and infrastructure adds pressure to the cliff edge, making it more likely to slump.

Also, rainwater runoff from paved areas can weaken the cliffs further by washing away soil and increasing the risk of landslides.

It is also important to consider the physical causes that contribute to erosion.

The cliffs at hay are made up of soft, unconsolidated material like clay, sand and silt, which are easily eroded by wave action.

The North Sea has a long fetch, which means that strong, destructive waves often hit the coast, especially during stormy weather.

These waves remove material from the base of the cliffs, causing them to become unstable and collapse.

In conclusion, while physical factors like geology and strong wave action naturally contribute to erosion at Happisburgh, human activities have significantly accelerated the process." This answer is great because it's explained the human activities, for example, coastal management strategies and caravan parks, but it has also considered the physical causes, like the geology and wave action.

At the end it's summarised perfectly that physical factors do play a role, but human factors are going to accelerate the coastal erosion at Happisburgh.

Fantastic, we've come to the end of our lesson in learning about change in a named coastal landscape.

You've done absolutely brilliantly.

Let's summarise what we've learned.

Happisburgh is one of the fastest eroding coastlines in the UK.

It is eroding at a rate of two to three metres per year.

The cliffs at Happisburgh are made of glacial till, which makes it vulnerable to erosion.

The North Sea's powerful destructive waves undercut the cliffs, causing slumping and rockfall.

Human processes have increased erosion by disrupting natural sediment flow to nearby coastal management, leaving the cliffs exposed and narrowing the beach.

The managed retreat policy and developments near the cliff edge, like caravan parks, have accelerated erosion by destabilising the cliffs.

Fantastic.

Well done for today's lesson, and I look forward to learning with you again very soon.