Lesson video

Hello and welcome.

My name is Ms. Harrison.

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

Today's lesson is called The Risks from Coastal Flooding.

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

By the end of today's lesson, you'll be able to understand the risks from coastal flooding.

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

The keywords in today's lesson are vulnerable, climate change and habitat.

Vulnerable is reduced ability to cope or withstand an event.

Climate change.

This is a long-term shift in temperatures and weather patterns.

Habitats.

This is the place where organisms live.

Brilliant.

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

The first question we are going to explore in today's lesson is, what causes coastal flooding? Coastal flooding is a serious issue for coastal areas and it happens because of heavy rainfall and strong winds, storm surges and high tides.

Heavy rain and strong winds contribute to coastal flooding by driving seawater towards the coast and increasing the wave heights, causing extreme flooding.

A storm surge is a temporary rise in sea level, which is caused by strong winds and low pressure during a storm.

The rise in water can lead to severe flooding, like you can see on the image on your screen.

True or false.

Storm surges are a cause of coastal flooding.

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

Excellent, the answer is true.

I would now like you to explain why this statement is true.

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

Excellent.

The reason why this statement is true is because a storm surge is a temporary rise in sea level, which is caused by strong winds and low pressure during a storm.

The rise in water can lead to severe flooding.

Well done if you managed to explain that correctly.

The main cause of tides is the gravitational pull of the moon on earth's oceans.

This pool creates high tides.

The sun also has a weaker gravitational pool and when the sun and the moon align, that means when they meet, that combined gravitational pool produces higher than average tides and these are called spring tides.

When high tides and spring tides happen at the same time as a storm, this can significantly increase the risk of coastal flooding for coastal communities.

What causes spring tides? Is it A, the gravitational pull from the moon and the sun, B, melting glaciers as winter turns into spring, or C, storm surges linked to low pressure systems? Pause the video here whilst you decide which statement correctly describes what causes spring tides and press play when you're ready to continue.

Excellent, the answer is A, the gravitational pull from the moon and the sun is what causes spring tides.

The text below is describing what causes coastal flooding.

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

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

Excellent, let's check your answers.

Your text should read like this.

Coastal flooding is caused by factors like heavy rain and wind, storm surges and high tides.

Heavy rain from storms can lead to flooding, especially when combined with strong winds that push seawater inland and increase wave height.

Storm surges occur when low pressure during a storm raises sea levels.

High tides are caused by the moon's gravitational pool, which naturally causes sea levels to rise.

When high tides and spring tides coincide with storms, the water level can rise even more in regular storms leading to extensive flooding.

Well done if you manage to correctly fill in the workflow.

The second question we are now going to explore in this lesson is why are risks of coastal flooding increasing? Climate change is the change in temperatures and weather patterns around the world.

Climate change is said to be increasing sea levels and increasing storm intensity.

Higher sea levels and more intense storms both increase the risk of coastal flooding.

Sea levels are predicted to rise between 30 centimetres and one metre by the year 2,100.

The map on the screen is of the British Isles and it shows the potential impact of sea level rise by 2,100.

The key on the right shows the estimated sea level rise in centimetres.

If we take a closer look at this map, you'll be able to identify which areas are worse affected and which areas will be least affected by sea level rise.

Areas that are a darker shade of purple or blue are going to be the ones that are worse affected and areas that are shaded in lighter shade of purple or even white, are going to be least affected.

But as we can see from this map, there are no areas in the British Isles that have been coated in white.

That means all areas of the British Isles will be affected to some degree by sea level rise.

If we look closer at the Thames Estuary, this map shows us what the impact would be of one metre sea level rise.

As you can see, there are many parts of this Thames Estuary that will be flooded.

This will destroy the communities, may cause people to have to lose their homes and their jobs.

Sea level rising is due to thermal expansion of oceans and melting of glaciers and ice sheets.

Thermal expansion of oceans occurs when water expands in volume as the water warms, causing the sea level to rise.

The graphic on your screen shows the contributions to global sea level rise between the years of 1993 to 2010.

As you can see, thermal expansion accounted for the greatest contribution to global sea level rise, showing the importance of what thermal expansion can do if the waters keep warming up.

Rising temperatures are also causing ice sheets and polar regions to melt.

This melting adds large volumes of fresh water to oceans and seas, which contributes to sea level rise.

Satellite images can be used to look at the differences in ice sheet cover.

The satellite image on your screen shows a change in ice sheet cover in Greenland between 2014 and 2020.

I would like you now to pause the video here and to take a closer look and see if you can identify what has happened with the area covered by ice sheets.

Press play when you're ready to continue.

Excellent.

You would've been able to notice that the Greenland ice sheet cover in 2014 is much greater.

In 2014, it's significantly reduced.

This means that this ice sheet has melted and it's added large volumes of fresh water to our oceans and seas and has significantly contributed to sea level rise.

This is only going to continue to get worse as site rising temperatures continue.

Higher sea levels mean that flooding caused by storm surges and high tides, can reach further inland than before.

The graphic on the screen shows the regional means sea level change.

I wonder if you can pause the video here and spot what the graphic is saying about the regional sea level change globally.

Press play when you're ready to continue.

Fantastic.

As you can see, the graphic is giving us a lot of information on things like small island developing states, coastal mega cities and deltas.

You can see on the graphic that the majority of the earth shows a regional mean sea level change of 0.

6 plus.

We can see that the areas that are gonna be worse affected are places that are small line in developing states, mega cities and deltas.

This is significant because it will contribute to the country's economic development, social cohesion, and may even lead to refugees.

True or false, climate change is increasing the risk of coastal flooding? Pause the video here and press play when you're ready to check your answers.

Excellent, the answer is true.

I would like you to explain why this answer is true.

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

Fantastic.

The reason why this statement is true is because warmer temperatures are melting ice on land, which is adding water to oceans and causing thermal expansion in the oceans, making sea levels higher, which increases the risk of coastal flooding.

Warmer ocean temperatures also mean more intense storms, which also increase the risk of coastal flooding.

Well done if you managed to explain that.

Warmer ocean temperatures produce more intense and powerful storms. The stronger winds, lower pressure, and heavy rainfall of these more intense storms will increase the risk of coastal flooding.

As you can see on the graph on the screen, the pink line resembles storm intensity and the blue line resembles sea surface temperature.

The graph is also measuring the degrees of storm intensity and sea surface temperature from the years between 1950 and 2020.

As you can see, for the majority of the years, there is a positive correlation between storm intensity and sea surface temperatures.

More frequent storms do increase flood risk, and in the 2023 to 2024 storm season, it saw 12 storms named.

This is the highest number of storms named since 2015.

Storm Babet, Ciaran, Henk, and Isha, all led to severe coastal flooding in the UK.

However, it's really important to note that there isn't currently enough evidence to say that climate change is definitely making storms more frequent.

True or false, scientists have not found any correlation between ocean warming and storm intensity.

Pause the video here whilst you attempt this and press play when you're ready to check your answers.

Excellent.

This statement is false.

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

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

Excellent.

The reason why this is false is because data shows a positive correlation for most of the years between rising ocean surface temperatures and measures of storm intensity.

Well done.

I would now like you to explain two ways in which climate change is increasing the risk of coastal flooding.

Sophia has asked a question.

She said that she's going to write about sea levels and storm intensity in her answer and she wonders if this sounds right.

Climate change is the long-term shift in temperatures and weather patterns.

If climate change is increasing the sea levels and increasing storm density, then yes, that does sound right.

Pause the video here and press play to continue.

Excellent.

Let's go and check our answers.

Your answer might include some of the following points.

As global temperatures increase, global warming, ocean water warms and expands, taking up more space and causing sea levels to rise, thermal expansion.

Higher sea levels will make low lying coastal areas more vulnerable to flooding.

Climate change is warming oceans, which is linked to an increase in intensity of storms. The stronger winds, lower pressure, and heavier rainfall of these more intense storms, will increase the risk of coastal flooding.

Well done if you managed to include some of the following points in your answer.

The final question that we are going to explore in today's lesson is what are the threats to people in the environment? Coastal flooding can significantly affect both humans in the environment and can make them extremely vulnerable to the effect of this.

I would like you to pause the video here and think about the threats from coastal flooding on humans and on the environment.

Press play when you're ready to check your work.

Excellent.

Let's go through this.

The threats to people include things like death and injury, damage to property, economic damage to farming, tourism, job losses, and the risk of disease, pollution.

The threats to the environment include the spread of pollution to wetlands, marine pollution, damage to natural habitats and coastal erosion.

Coastal flooding can cause significant damage to properties.

It is said that 5.

7 million homes across England are at risk of coastal flooding.

Flooded homes, and businesses often require lots of work to make them useful again.

As you can see on this image on the screen, there is devastating effects from this flood on this high street.

The shops will close.

People will lose their money as they aren't able to attend work, but also the businesses will have to forecast a lot of money to repair the stores.

Tourism is a really important source of income for coastal areas and coastal flooding can significantly impact coastal tourism by damaging the hotels and attractions, leading to costly repairs and reduce visitor capacity and sometimes even deterring visitors to coming back again.

Storm surges can have devastating effects.

In December, 2013, Storm Xaver produced a storm surge of two metres on the east coast of England.

This is the highest storm surge in England had seen since 1953.

The flood risk map of storm Xaver shows you the extent of the effect that storm Xaver had.

The whole of the east coast have red flood warnings.

That means there is risk to life.

The impacts of storm Xaver was devastating.

Two people sadly lost their lives.

Seven houses were completely destroyed.

1,600 homes were flooded along the east coast and 10,000 homes are evacuated.

All of this caused a total damage of 8.

1 million pounds.

Coastal flooding can cause pollution.

When sewage works are flooded, untreated sewage is spread by flood water, which can create waterborne diseases and make people extremely ill.

Flood water can also pick up and spread chemicals from fields where farmers are working.

This can also cause animals to die if they consume these chemicals.

When flood waters recede, that means when they drain back into the sea, they can also carry rubbish along with it, which increases the marine pollution.

Marine pollution is pollution of the oceans and seas.

Coastal flooding impacts habitats by disrupting ecosystems like wetlands with salt water.

This can cause increased salinity levels.

This means higher salt levels and harm wildlife.

Most plants can't tolerate salt water and coastal flooding can cause crops to be completely ruined on farmlands.

Coastal flooding also plays an important role in increasing coastal erosion.

It can create higher water levels, which means waves reach higher up the beach and cliffs, exposing more areas of the coastal erosion.

Flood waters saturate the ground, which can make them really heavy and loosen it and make it more vulnerable to mass movement and erosion.

Flooding can also weaken sea defences by undermining their foundations, making the cliffs or the beaches exposed to the waves.

As flood waters recede, that means they drain away, they can carry sediment back towards the sea, eroding it from the land.

True or false, coastal flooding only threatens people and not the environment.

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

Excellent.

The answer is false.

I would now like you to explain why this answer is false.

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

Excellent.

The reason why this answer is false is because coastal flooding can carry pollutants that damage the environment as well as being a threat to people, and salt water is toxic to many organisms. Which of the following are threats from coastal flooding to both humans and the environment? Is it A, fatalities from storm surges, B, increased plastic pollution in oceans, C, plants killed by salt water, or D, flood water spreading pollutants.

For this question, you may select two answers.

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

Excellent.

The following threats from coastal flowing to both human and in the environment are, C, plants killed by saltwater, and D, flood water spreading pollutants.

Well done.

I would now like you to complete the table on the impact of coastal flooding.

The effect we're going to focus on are property damage, contamination, displacement, and increased salinity.

Remember, salinity simply means salt levels.

I would like you then to focus on how each of these effects impact on people and the environment.

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

Excellent, let's check our answers.

The effect, property damage.

Its impact on people.

Homes and businesses may be destroyed or severely damaged leading to economic losses, for example, tourism.

The impact on the environment.

Flood waters spread waste from damaged homes into local habitats.

Contamination.

The impact on people, increased risk of waterborne diseases if sewage works are flooded and untreated sewage is spread by flood water.

The impact on the environment.

Pollution can harm aquatic ecosystems and wildlife habitats.

Displacement.

The impact on people.

Communities may be forced to evacuate, causing loss of homes and disruption to livelihoods.

The impact on the environment.

Displacement of wildlife from the natural habitats can disrupt local ecosystems. Increased salinity.

Crops or plants cannot tolerate salt water, so farmers may lose crops affecting their yield and income.

The impact on the environment.

Increased salinity levels in freshwater wetland habitats can harm plants and animals.

Well done if you manage to include some of the following points.

Fantastic.

We've come to the end of our lesson on learning about the risks from coastal flooding.

Let's summarise everything we've learned about in today's lesson.

Coastal flooding is caused by heavy rainfall, storm surges, and high tides.

All of these can be intensified by climate change.

Rising global temperatures lead to melting ice sheets on land and thermal expansion of seawater, both of which contribute to sea level rise.

The impacts of coastal flooding include fatalities, property damage, disruption to businesses, and water contamination for humans, as well as destroying habitats and increasing coastal erosion.

Well done for all your work in today's lesson.

We've had a fantastic time.

I look forward to learning with you again soon.