Intro Quiz: Managed retreat

Video: Managed retreat

﻿Good day Geographers and welcome to this coast lesson today about coastal management. We're going to be specifically looking at managed retreat. There is a hard decision to make between hard engineering, soft engineering, or managed retreat. The councils only have so much money. And so it's a really difficult decision to make sure that you're making the right choice to protect that bit of coastline. People's lives could be at stake. So for today's lesson all you're going to need is a pen and paper. In a second, I'm going to ask you to pause, go and find what you need, and make sure you clear away all those distractions. If you want to go and work somewhere quieter, please take that opportunity. Off you go and get what you need and I'll see you in a second. Perfect, so today's title is managed retreat. Write at the top of your piece of paper, underline it beautifully, and we'll get started straight in. We're going to start this lesson by having a look at what types of management there are for our coastline. The first type is hard engineering, and this is where we use artificial structures to defend land against natural erosion processes. There are four types of hard engineering, groins, gabions, sea wall and rock armour. These all look at stopping coastal processes like corrosion. An alternative to these, are soft engineering management strategies. This is where we manage erosion by working with the natural processes to help restore beaches and ecosystems and therefore reduce erosion. Our soft engineering strategies are, dune regeneration, reprofiling and beach nourishment. Should you need to go over any of the soft or hard engineering strategies, there are videos available for you to do this. So, which is the odd one out. How well do we know our management strategies? Five seconds, write down your answer for me. And it is reprofiling. Just tell me now out loud why is reprofiling the odd one out? It is the only soft engineering process there. The other three are all hard engineering. And one final challenge for you. There are four hard engineering strategies. Tell me what the fourth one is. Which one is missing? Did you get sea wall? Good, well done. Right, let's get started straight away. I would like you to make a table on your line paper, ideally with the ruler, it's important that we get these looking nice and neat. Can you please categorise those seven types of coastal management strategies into hard engineering and soft engineering. Pause the video for me now and join me when you're done. Let's check them. Get ready to tick them off. Hard engineering strategies were, rock armour, sea walls, groins and gabions. The soft engineering strategies were beach nourishment, dune regeneration and reprofiling. So give yourself a big score out of seven. Hopefully you've done really well. But today's lesson is all about managed retreat. And with managed retreat, we remove all the current defences and we allow the sea to flood the land behind it. This is a super important definition. So can you pause now and get this key term written down in your notes for me please? And what managed retreat does, is it looks at undoing all the human activity. It removes any coastal protection that's being put in place. So there's sea walls, or we've got rock armour in this image. Everything that's been put in place before to stop coastal erosion is removed. The point of this is to allow areas once protected from flooding to be flooded and to be eroded by the sea. And that will inevitably change the shape of our coastline. As sea levels continue to rise, managed retreat seems likely to become more popular in the future. Once this has happened, beaches build up due to the large amounts of newly eroded material. And this creates a natural defence against erosion. In other locations, salt marshes occur, which also act as a defence against the destructive waves and it also has the benefit of providing new habitats. Managed retreat is a natural, sustainable long term solution to managing the coast. Let's have a look at the advantages of managed retreat. It is cheap, but you do need to compensate the people who own their land that gets flooded. For example, this is normally farmers. It doesn't require maintenance, which keeps the cost low. It can also create new coastal habitats, which will attract wildlife and birds to the area. There are some disadvantages though. It can cause conflict. Flooding farmland can affect a farmer's livelihood. So people really struggle if their area of the coast is designated as an area for managed retreat. Salt water can have a negative effect on some ecosystems that already exist. And it's not possible everywhere. It tends to only occur when there is low value land. You couldn't attend managed retreat on a town that was located along the coastline. The land used behind is too expensive. Let's put that learning to the test then. So which statement is incorrect about managed retreat? You're going to need some time to read these. So pause now, which option is the incorrect one? Let's check, hopefully you went for option two. So manage retreat involves creating manmade barriers to protect the coast. That one is false. What does manage retreat involve? You've got it. It involves removing all existing management. So we're taking it away, so the coastline can retreat. Let's get this down on paper. So I would like you to categorise these impacts of managed retreat. There are six to do, and I would like you to sort them into advantages and disadvantages. Make sure you draw the table really neatly with pencil before you tackle it. Pause the video now to complete your task. Let's check your advantages first. So you should have that the advantages of managed retreat are, that it is cheap. It doesn't require maintenance and it can create new ecosystems. The disadvantages are that, managed retreat is not possible everywhere. Salt water can affect existing ecosystems, and farmers can lose land. So hopefully write six nice big ticks on your work, well done. Why might managed retreat be suitable then in this location here. Pause the video and just take 10 seconds to see if you can come up with two reasons why. You can see down this side of the image that they have attempted to manage this coastline. So why now would we decide to use managed retreat? Hopefully then, looking at this photo, you can see that the cliffs are eroding and retreating at quite a rapid rate. You can see that the cliff is zigzagging in and out where mass movement has occurred. I would say it's been happening quite quickly because I can see pipes coming out of that cliff, which was just that they weren't prepared or ready for these cliffs to retreat. A second reason I would suggest is the cost of the land use. We can see Caravans, not houses that people live in all year. So this will suggest that the land used is quite low. The cost of protecting this area using hard engineering is probably greater than the benefits. We're going to look at an example now of Medmerry managed retreat. And we've got a satellite photo here showing the area. At Medmerry near Selsey in Sussex, an earth embankment was originally built in the 1960s to prevent the sea flooding the land. In 2008, this previous defence was breached causing over 5 million pounds worth of damage. The environment agency was spending up to 300,000 pounds every year maintaining that wall through reprofiling. This flat low line coast was mainly used for farming and Caravan Parks. So rebuilding the seawall was deemed to be too expensive and they made that decision to move to managed retreat. The sea was allowed to breach in November, 2013, and you can see where that happened. Although the area allowed to flood was limited, it built an embankment around the outside to make sure the area was controlled. Natural mudflats are slowly being created by the advancing tide, and it will create a large natural salt marsh to act as a buffer to the sea. Medmerry managed retreat scheme was seen as successful. It created a large, natural salt marsh to act as a buffer to the sea. It protected surrounding farmland and caravan sites from further erosion. And it created a wildlife habitat. And that was really good for tourists to come and visit as well. However, the cost of this was 28 million pounds. But if we remember from earlier, the environment agency was spending 300,000 pounds every year, just maintaining the beach through reprofiling anyway. Using maps and satellite images is a really important skill in geography. I would like you now to use the Ordinance Survey map to identify feature A, B and C on this satellite image. So pause the video now and have a go. I want you to write them down on your paper, A, B and C. Right, how did you get on? The first thing when you're looking at matching up a satellite photo to a map is to look for something you can see on both to help you locate things. The thing that I can see is this raised in bank around the outside of the managed retreat area. It's curves are really recognisable on this OS map. And I would in an exam, use a highlighter to highlight that on the OS map to give me some help. Where we look at site A site A is a triangle shape of buildings surrounded by farms. If I show with my mouse, it's just on this first bend here on the left hand side. So if we go over to the OS map, you can see that triangle of buildings and you can see it labelled as marsh farm. So A is marsh farm, give yourself a big tick hopefully. B, is located to the South of the satellite image along the coast. You can see that there are some buildings, so though it's very difficult to see what they are. If we have a look at the OS map, you should have identified that, that area is down here and it is a Caravan Park. Finally C is located next to the line of the managed retreat and it is Greenwood farm. In most topics in geography, we talk about things being sustainable. With coasts we want the management to be sustainable. Sustainable management, is management that meets the needs of the present without reducing the ability of future generations to meet their own needs. If something sustainable, we talk about it having social advantages, economic advantages and environmental advantages. Medmerry was socially sustainable. The area of managed retreat reduced the flood risk for 348 homes and properties. This meant that people didn't need to worry about their homes flooded anymore. It also provided an area where people could go for walking and to observe wildlife. This is socially sustainable, as it meant that people had things they could do in their free time. It was economically sustainable because even though the cost was 28 million, they believe that the direct economic benefit of this managed retreat was 90 million pounds. This included things like tourists visiting the area and spending more money because lots of green tourists came to the area. Green tourism is where people would go and enjoy the natural environment. So people were going to look at the salt marsh environment then going birdwatching. Also the Caravan Parks, because there are no longer at risk of flooding, they could open up for a longer season. So they didn't need to shut this early in winter because of the flood risk. Finally, cows that graze on salt marsh grasses have a higher percentage of salt in their milk. This is really desirable by people that buy milk. And so therefore farmers earn a larger amount of money if the sole percentage of milk is higher. Finally, Medmerry was environmentally sustainable. It created 183 hectors of intertidal habitat. This created new habitats and encouraged new wildlife to the area. So how much can you remember? What was the economic benefit of Medmerry's managed retreat? Five seconds, jot down your answer. Did you get 90 million? So it wasn't 28 million, but we have heard that figure. Can you tell me now what was 28 million? It was the cost of the management. Well done if you've got that one correct. But which statement is incorrect about Medmerry's managed retreat? I would like you to pause to do this because you're going to have to read through all of them. What did you choose? Hopefully you went for options three, cows grazed on a salt marsh have a higher salt percentage in their milk. So time for the main task, I would like you to explain why managed retreat can be seen as a sustainable option for managing the coastline. It's four marks. So what's going to make this answer super. I would like you for four marks to have two developed ideas. Even though the question doesn't say name a case study, I'd really like you to refer to Medmerry. It will improve the quality of our answers. And I would like you to categorise, how is it sustainable? Remember we can talk about things being sustainable socially, economically, and environmentally. I've gone through and I've had a go at an answer myself. Managed retreat in areas like Medmerry, Essex is a sustainable option for managing the coast. In this introductory sentence, I've named the example that I'm going to be talking about. I then go on to have a look at social sustainability. The 28 million pound project is socially sustainable as the salt marsh has created store large quantities of water. So therefore that signals I'm developing. So therefore protect 348 nearby homes and properties from flooding. I've done social sustainability. So I'd really like you to be brave and tackle economic sustainability and environmental sustainability. Pause the video, take you four minutes, best of luck. Right, let's have a look. How did you do? Nice introductory sentence. You could have taken mine, managed retreat in areas like Medmerry, Essex is a sustainable option for managing the coast. The 28 million pound project is economically sustainable as surrounding farms can now graze their cows on salt marsh grass, which increases the salt percentage in their milk, meaning they get paid more. Medmerry is also environmentally sustainable as it has created 183 hectors of intertidal habitat, which means that many birds and other wildlife moved into the area, increasing biodiversity. I'm going to give you another example of economic sustainability, cause you could have done a different one. So the 28 million pound project is economically sustainable as it has increased green tourism and allowed Caravan Park to open for longer, resulting in an economic benefit of 90 million pound to the area. So put your ticks in the right place. Check you've got your categorization like I have in purple. Check you've got your connectives to show you've developed and those are the blue terms. Excellent way of tackling that, well done. Well, that brings us to the end of today's lesson. Thanks very much for all your hard work. We've learned today about managed retreat as an alternative to hard or soft engineering. It may be cheaper. It may create habitats, but someone is always going to lose their land. It's a difficult decision to make. But I don't want to lose you yet though. Don't retreat just yet. I need you to manage your learning by summarising it on the quiz for me on the next tab. Thanks for your time today, take care. And I look forward to you joining me soon as we take a look at how Lyme Regis has made those tricky decisions, and chose to manage their coastline. Have a great day.

Exit Quiz: Managed retreat

Completed: Managed retreat

In this lesson we will look at managed retreat that is sometimes used along our coastline.

Geography

Managed retreat

Introductory Quiz

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Final Quiz

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