Lesson video

Hello geographers.

It's Mr. Robertson here and welcome to another fantastic geography lesson.

We're going to be continuing with our unit, "Rivers, What's Special About Them?".

Over the course of this unit, we have followed the journey of the river.

We've learned about the land forms, such as waterfalls and meanders that we might find along its course.

Last lesson, we started to look at the idea of flooding and explored why rivers flood.

Today's lesson is called, "Flooding Impacts and Solutions".

And we're going to be thinking a little bit about how we can help to prevent floods as well.

So geographers, we need to make sure we've got on our geography caps, very wide brimmed and water resistant.

We need to have packed our waterproof explorer rucksacks.

And we're not forgetting our really long and excellent Wellington boots.

Let's find out what we are learning today.

So by the end of this lesson, you will be able to explain the short and long-term impacts of flooding and describe ways that flooding can be reduced.

We have four key words in this lesson.

I'll say the words first and then I'd like you to say them back to me.

Our first words are digital map.

Beautiful.

Our second word is embankment.

Amazing.

Our next words are drainage basin.

Fabulous.

And finally, evaporation.

Ah, ah, geographers, really well said.

Let's find out what these geographical words mean, shall we? So digital maps are maps that could be viewed on a computer.

Embankments are where the sides of the river are raised to stop water escaping.

A drainage basin is the area drained by a river and its tributaries.

And evaporation is where liquid heats up and turns into a gas.

We're going to be using all of these keywords in our lesson today and by the end I'm really confident you will know what they mean.

So our lesson today is all about flooding impacts and solutions and we're going to do that in two parts.

In the first part of the lesson, we're going to be asking the question what are the impacts of flooding? And in the second part of the lesson we're going to be asking what are the solutions to flooding? So let's start by looking at the impacts of flooding.

Let's go.

Look at that photograph there, we can see a really large flood, can't we? If you look at the back, you can see there's a log, isn't there? A tree trunk floating in there.

And we can barely see those fences or bushes and trees can we? Because the water has risen up so far.

So flooding can have a really big impact on people and wildlife.

Looking at this photograph, I'd like you to talk to the person next to you.

Why will humans and wildlife be affected by the flooding in this photograph? Pause the video, talk to the person next to you.

A lot of fantastic discussions that you're having, yes.

We can see, can't we, that those animals, those cattle, they're only on a tiny strip of land, aren't they? So they've got very little area to eat and graze.

So it's gonna be really difficult for them, isn't it? These fields probably belong to a farmer and so their livelihood, their income is going to be affected by this flood, isn't it? Because the animals won't be able to graze on the grass and that's going to affect how much they will be able to produce.

And what about other wildlife as well? Some of the birds and animals and invertebrates that live in these fields, they're going to be harmed as well because they won't be able to hunt for food, maybe their homes will be destroyed.

So flooding by rivers can have a big impact.

When rivers flood it can cause short-term problems and long-term problems. So what do we mean by that? Well short-term problems are issues during and immediately after the flood and they don't necessarily last for very long.

Whereas a long-term problems are issues that may last for a long time.

Look at this photograph here.

You can see, can't you, that the river has burst its banks and it's flooded the road, so of course the road is closed.

That means if you live in the village you might not be able to get out.

Or if you wanted to come into the village, you might not be able to get there.

Now do you think that this is a short-term or a long-term problem? I'd like you to turn to the person next to you and say what you think.

Pause the video.

Well done.

Jacob's been doing some thinking about this as well and he says, "I think this is quite short-term, as the water will go down and the road can be opened".

Hmm, I think I agree with you Jacob.

Hopefully that's quite a short-term problem.

What did you think? Did you agree with Jacob? Well done if you did.

Now as well as that, look at what happening in this photograph.

We can see a severe flood here, hasn't it? And the river has risen up, burst its banks and it's come and some homes and some shops have been flooded.

We can see the water is up past the wheels of lots of those cars, isn't it? And so it will probably have gone into the houses.

Do we think this is a short-term or a long-term problem? Again, I'd like you to pause the video, turn to the person next to you and say what you think.

Great thinking geographers.

I can really hear some discussions here about whether this is short-term or long-term.

Sofia's been doing some thinking and she says, "I think this is a long-term problem as the houses might need to be repaired".

I think Sofia might be right because the water may go down but then there'll be a lot of damage inside the houses, won't there, where the water's got in.

Carpets will be ruined, there might be some damp in the walls, they're gonna have to be repainted, there might need to be some new furniture.

So all of those things are not going to be sorted out quickly and so this is a long-term problem.

Thirdly, we might think about this, if an area floods regularly, people might not want to buy a house in that area.

And so the house price, the amount of money that people can get for their house might drop.

And so people might not be able to get as much money as they wanted and their house value might go down.

Do we think that this is a short-term or a long-term problem? Again, I'd like you to pause the video, talk to the person next to you.

What do you think the answer might be this time? What an interesting discussion that you're having.

So Sofia's been thinking about this as well and she says, "I think this is a long-term problem as the house prices might keep falling".

Yes Sofia, I think you might be right because it's quite a big issue, isn't it? If house prices fall, that won't necessarily change really quickly and so this could be another long-term problem of living in an area where there is flooding.

Well done if you managed to think of a similar answer.

Let's look at an example in the UK.

You can see here a photograph and this is a photograph of a town called Shrewsbury.

And Shrewsbury is a town in Shropshire in England.

It's a really beautiful town actually if you've ever been there or maybe you actually live there.

The river Severn, the UK's longest river runs through the town and you can see a photograph, can't you, of the river Severn, really big impressive river.

And you can see that stone bridge, can't you? Spanning the river Severn.

Now the river Severn sometimes floods part of Shrewsbury, but actually Shrewsbury is having more flooding because flooding is becoming more common in Shrewsbury.

And we know this is one of the consequences of climate change, isn't it? That there is going to be more and severe flooding.

Let's check our understanding.

So river flooding in Shrewsbury is A: Becoming more common; B: Becoming less common; C: The same risk as in the past.

Pause the video, have a think.

Well done geographers.

It's A: Becoming more common, isn't it? So they're having more flooding in Shrewsbury.

Now we can look at the risk of flooding by using digital maps.

So here is an example of a digital map of Shrewsbury.

And you can show that it's giving us the aerial view.

You can see the word Shrewsbury in the middle, so that's marking the centre of the town of Shrewsbury.

And around it we've got some colours and you see we've got four different colours there, ranging from a very dark blue up to a very light blue.

And these colours talk about the risk of flooding.

And by risk I mean how likely it is that something is going to happen.

The darker colours on the map show where it's most likely to flood.

So the top there is high risk, meaning that there's a much greater chance of a flood.

And probably not surprisingly, you can see that the highest risk of flooding is close to the river.

So if you look very carefully at that digital map, you can see the river meandering through the town of Shrewsbury and the darkest colours are found around it, so these areas are very likely to have a flood.

Now we can compare that sort of map, a flood risk map, with an aerial photograph to see who will be affected by flooding.

So now on your screen you can see an aerial photograph of Shrewsbury and we know it's a photograph because we can see features such as the grass of some of the open spaces and we can see buildings and we can actually see the river Severn as it meanders all the way around the centre of Shrewsbury.

So the interesting thing is going to be, if we compare them together and that will allow us to see where in Shrewsbury is most likely to be affected if the river floods.

So here we've got the flood risk map at the digital map and here we've got the aerial photograph.

And what we can do is we can trace over the flood risk map and then compare it and that will allow us to see which areas are most likely to be affected.

So let's do that now.

What I've done here is I've drawn a line around the area which is the highest risk of flooding.

So this area you can see follows the course of the river and this area's got the most likely chance of flooding.

Now I've put this over the aerial photograph.

Do you notice which areas of the town are most likely to be flooded? Maybe you could look quite closely and see if you can spot any.

You might have noticed that there's a church centre there circled, Barnabas Church Centre.

Look, that is a place where there could generally be some flooding.

In the middle we've got the Pride Hill Shopping Centre, so that's built quite close to the river and so it's really likely that if the river flooded that the shopping centre would be flooded.

And then we've also got Hickory's Smokehouse, so I imagine that that sells fish and smoked seafood.

And again, that could be flooded 'cause it's really close to the river.

And so by having the flood risk map and the aerial photograph together we can identify where in Shrewsbury is most likely to be flooded.

Let's just check our understanding about that.

Where on this map has a high flood risk and where has a very low flood risk? Geographers think about what we've been learning about the colour coding.

Talk your partner, pause the video.

Well done geographers.

It's the darker blue areas isn't it, that have the highest flood risk and they're often the ones that are closest to the river, whereas the lightest blue have a very low flood risk and those are very unlikely to flood.

Now flooding isn't necessarily a bad thing everywhere.

You might have done some learning about the ancient Egyptians.

And the ancient Egyptians actually lived along the River Nile in Egypt.

And they relied on the fact that every year the Nile flooded and that helped water the crops and it also left some sediment and mud behind, which was really fertile so the ancient Egyptians could plant their crops.

And actually if the Nile didn't flood every year, it's highly unlikely that the Egyptian civilization would've grown up as it did.

So floods can have a positive impact, as well as a negative impact.

Let's just check our understanding there.

I've got a true or false question for you.

Flooding only has bad impacts.

Is that true or is that false? I'd like you to pause the video and have a think.

Yes you're absolutely right geographers, it's false isn't it? Flooding does not only have bad impacts.

But can we think about why that's the case? I'm going to give you two answers and I'd like you to choose the one that makes the most sense.

So answer A: Flooding helps clean cities and towns.

Answer B: Flooding can help crops grow in some parts of the world.

Which of those make sense? Pause the video, have a think.

Excellent geographers, it's B isn't it? Flooding can help crops grow in some parts of the world.

We were just talking about that, weren't we, with the Nile and the ancient Egyptians.

Flooding definitely does not help clean cities and towns, in fact it can cause a real mess, can't it? And really damage property.

Right.

So our first practise task is going to be thinking about the impact of flooding and I want you to show your understanding of using this flood risk map and how we interpret it, 'cause this is a really important geographical skill.

I've got a map for you here which shows a part of a town and it's got the flood risk map on it as well.

So I'd like you to do this, I'd like you firstly to label the map to show the features and groups of people that are at risk from river flooding.

So to do that you're going to need to identify which part of the map shows it's got a high risk of flooding.

Find the colour on the key and then look at the map.

When you've done that, have a look at some of the places that that colour covers, what sort of people might use those facilities and are there any particular buildings you recognise? Once you've identified which features and groups of people are most at risk from flooding, I'd then like you to think about whether this will have a short-term or long-term impact.

In other words, if that area is flooded, is that a short-term problem? If the river goes down, it will be okay and get back to normal quite quickly.

Or will it be a long-term problem? Even when the flood water retreats, will there still be issues that need sorting out that might take quite a lot of time or money.

Good luck geographers.

Really excited to see how you interpret those maps.

See you soon.

Well what a lot of discussion and thinking you've been having, thinking about the risks of flooding.

You might have noticed that Shrewsbury High School might be at risk of flooding because that area falls into the dark blue zone, which was the highest risk, wasn't it, of flooding.

So therefore pupils and teachers will be affected there.

You may also have seen that there are some roads and other buildings that might be at high risk of flooding, so that's going to cause a problem as well.

And you may also have noticed there are some sports facilities, look, there's a bowling green, there's a tennis court and so people who play sport, those areas are at high risk of flooding as well.

Well done if you spotted some of those.

Now we might explain some of the short and long-term impacts of that.

So here I've written river flooding may have short-term impacts, such as road closures, school closures and sports club closures.

Because all of those places will have to close won't they, if there's a flood.

People won't be able to play tennis in a flood, it'd be difficult to drive along the roads and the school will be overwhelmed as well.

But river flooding might also have long-term impacts on things such as houses and other buildings belonging to the school, because they might be damaged and need repairing.

And so even when the flood water goes down, the school classroom may be damaged, carpets, equipment and that will take a long time to fix, so that's gonna be a long-term impact.

Well done if you managed to think through some of the impacts there.

So in the second part of the lesson we're going to be investigating what are the solutions to flooding? Let's go.

So one of the things that people try to do to reduce the impact of floods is warn people if a flood is likely.

And we have organisations that can help with that.

For example, the Met Office who predict the weather and the Environment Agency, whose job is to measure river levels.

What they do is they work together and see if a flood is coming and then they can warn people in advance so they can try and make sure they get out of the way or move equipment in time.

Why is it helpful for people to be warned that a river is likely to flood? Why don't you talk to the person next to you and see if you can come up with some ideas.

Awesome.

Really interesting ideas I can hear you coming up with, yes thinking about this idea of a flood warning and why it might be helpful.

So Alex has been thinking about this as well and they say, "I would like to know if a river is likely to flood, because then I can try and prepare properly".

Yeah, you might want to do something like move some of your furniture upstairs if you're in a house which has got more than one floor so it doesn't get damaged.

You might want to make sure you've moved precious things out of the way.

You might want, if you were a farmer, to move your animals.

And so flood warnings can be really helpful.

Digital maps can be used to warn people if a flood is likely to happen.

Here's an example of a digital map and we can see there are some flood warnings using a colour code.

The orange on a map shows a flood alert for those areas.

So you can see there's the city of Shrewsbury down towards the bottom.

And then we've got some other areas where there is a flood alert.

You might see some surrounding the place Long Lane or Wem.

And so people will know that if they live or work in that area, there's a chance that there's going to be a flood.

When people are warned about a flood, they can start to prepare.

I've got some questions for you here and I'd like you to think about how people might prepare.

So how might schools prepare for a flood if they know a flood is likely to happen, what might they need to do? Secondly, what about people who own a shop or a home, how could they prepare for flooding? And what about people in charge of roads, how could they prepare for flooding? I want you to think very carefully here, use your geographical skills and think if you can come up with an idea for each of them.

Pause the video, talk to the people around you, see what you can come up with.

What a lot of amazing ideas you're having.

Maybe you should be flood planners when you're older, really thinking about how we can cope with these events.

So Lucas says, "The Headteacher might decide to close the school".

Yes, that way we can guarantee that pupils are safe, they could do some online learning, perhaps with Oak, and that will help them keep going over their schooling.

Sofia says, "People sometimes use sandbags to try and stop water entering their home".

You might have seen some of these sandbags, they're like a bag in a cloth or sacking and you can pile them up around doors, which just helps keep the water back and the flood water entering.

And so people might be able to put some sandbags against the edge of their homes or their shops, just to keep the water out a bit longer.

And Lucas says, "The council could close roads to stop people getting stuck".

What a great idea.

If we know that the roads are going to be flooded, then we could perhaps get people to go on different roads instead.

So lots of really practical ways we can prepare, so if a flood happens, people aren't caught out or aren't put in danger.

Now another thing that we might want to do, if there is an area where lots of homes, shops and offices are at risk from flooding, people might try to stop the river flooding by building a structure or changing the river.

Because the things we talked about earlier, like sandbags, we can do that, that's a temporary thing if floods are actually going to happen.

But a more long-term solution would be to actually do something to help prevent the floods in the first place.

Look at this photograph here, you can see the river, can't you? But on either side, can you see those big concrete walls? They are known as embankments and they're sometimes built next to the river so it's harder for the water to rise over the sides.

So what we've done is we've raised the level of the banks by building those embankments, they're made of a really strong material like stone or concrete, so that they can't be eroded away.

And they also curve out so that water will sort of be pushed back and that means that the river can rise higher than it would normally before it floods, and so it gives a bit of safety to people living in that area.

So embankments can help stop flooding by A: Removing water from the river; B: Raising the sides of the river so water can't get out as easily; Or C: Raising the height of the river.

Fantastic.

It's B, isn't it? Raising the sides of the river so water can't get out as easily.

Another way to reduce the risk of flooding is to plant trees in the drainage basin.

You can see some beautiful saplings there, can't you, that have been planted.

Now why might this reduce flood risk? If you were at the last lesson, we talked a little bit about the role of trees in drainage basins, so I wonder if you could think back to that lesson.

Pause the video, talk to the person next to you, what is it about trees that might help reduce flooding? Off you go.

Awesome.

Brilliant discussions there.

Well done geographers.

Well trees, we talked about this last time, collect and store rainwater and that stops it getting to the river.

Look at the diagram here, we've got a diagram of the water cycle.

We can see here that it's raining, now the trees can catch the rainwater.

As the rain drops fall, they get caught in the leaves and they run down the trunk to the bottom and also the water soaks around it.

Now the roots of the trees can store the water in the tree and that's absolutely brilliant because that means less water is going to be getting to the river.

Some of the water collected by trees will evaporate.

So imagine a tree in the rain, the water will get onto the leaves and the tree will get very wet.

Then when the sun gets out and warms up, that will cause that water to turn to water vapour and evaporate away, which means that it isn't getting into the river, which is fabulous.

And then the rest of it will be stored in the roots and trunk of the tree.

Now all of that means that less water will flow to the river through the ground, over the ground, through the soil and through the rock, which means that there will be less water getting into the river, which means it won't be able to rise as much, which means that there will be less chance of flooding.

So planting trees is a brilliant thing.

It's a brilliant thing for all of us, isn't it? But it's really helpful for helping to reduce the risk of flooding.

Let's just check our understanding here.

True or false? Trees can reduce the risk of rivers flooding.

Is that true or false? Pause the video, have a think.

Well done geographers, it's true, isn't it? Trees do reduce the risk of rivers flooding.

But why is that? I'm going to give you two answers and I'd like you to think which of these is correct, is it A: Trees take water out of the rivers; Or B: Trees collect and store rainwater and stop it reaching rivers.

Again, pause the video, have a think.

Well done geographers, it's B, isn't it? Trees collect and store rainwater and that stops it reaching rivers.

Well done if you got that right.

So our final practise task is this, we've got our diagram there of the drainage basin that we've been using all the way through this unit of work.

I'd like you, firstly, to add two features to the diagram to show ways that the risk and impacts of flooding could be reduced.

Can you remember the two different features that we've been looking at in this part of the lesson? You might want to think where exactly you might put them on the diagram.

And then once you've done that, I'd like you in a couple of sentences to explain why these might help.

What is it about doing these things which will help reduce the risk of flooding? So add the features to the diagram, clearly label them, think about where on the diagram they might go.

And then secondly, a sentence or two to explain why they help to reduce the impact of flooding.

Well done geographers.

Good luck.

Look forward to seeing what you say.

Well geographers, let's see what you came up with.

So you might have come up with the idea of embankments.

And of course these are artificial features and they could be built next to the river.

This would make the sides higher so the river could hold more water.

Do you remember that photograph we looked at earlier of the city with the two concrete embankments on either side of the river? And that's brilliant, 'cause it means that the river can rise higher and it won't go over the top and flood.

So embankments is one solution.

Another solution is to plant trees or more trees in the drainage basin.

And this is brilliant 'cause it's a natural solution and it means that when it rains, the trees will store the rainwater and slow it getting to the river, which will reduce the amount of flooding.

So well done if you thought of embankments and you thought of trees.

Brilliant, you are really thinking of some solutions to flooding.

So we've been learning all about the impact of flooding and some possible solutions.

We've learned that river flooding can cause short-term and long-term problems. We've learned that digital maps can be used to show areas at risk from flooding.

We've learned that the impacts of flooding can be reduced by warning people in advance.

And we've learned that the risks of river flooding can be reduced by building embankments and planting trees.

So I've really enjoyed learning about flooding and it's made me really understand a lot more about what we can do to help reduce flooding at all.

I hope you've enjoyed it and I look forward to seeing you in our next lesson in this unit.