Lesson video

Hello, my name is Mr. Conway.

I'm very pleased to have the opportunity to guide you through this geography lesson, and there's gonna be a particular emphasis on using GIS or geographic information systems. So let's get started.

This lesson is part of the Climate Change Unit, and by the end of today's lesson, the intention is that you'll be able to use 2D and 3D GIS to visualise climate change impacts.

So some of the learning about GIS may be new to you, but I'm here to help you along the way.

To help us achieve the outcome, we need to learn or remind ourselves about a few keywords.

These the keywords for today's lesson.

geospatial data, media layers, and elevation profile.

Let's look at some definitions for each of these keywords.

Geospatial data is georeferenced information, which includes quantitative data, for example, numbers, or qualitative data such as photographs, which has been linked to a particular location, a particular geographical place.

Media layers are overlays of scanned maps.

They could be aerial or satellite images, which can be georeferenced to line up with other layers.

And Elevation Profile is a GIS tool, which we can use to visualise changes in height above or below sea level, and we measure them and show them along something called a transect line.

Our first learning cycle will help us to use 2D GIS media layers to visualise changes linked to climate change.

And the second learning cycle is gonna help us to use 3D GIS media layers to visualise changes.

So we're going to look at the first of these learning cycles now.

The Caspian Sea is the world's largest inland water body and the world's largest lake that's technically known as endorheic basin.

All of it is entirely below sea level.

Even the top of the water in the Caspian Sea is below the level of the oceans of the world.

So the Caspian Sea is undoubtedly quite a special place and it supports a whole range of ecosystems and there are rare and endemic species of both flora and fauna and one of the fauna that's rare there is the Caspian seal.

The changes taking place there due to climate change are very significant.

It means the Caspian Sea is under quite serious threat.

So in this lesson, we're gonna ask ourselves the question, how can GIS visualise and analyse such climate change impacts? First of all, GIS involves georeferenced maps, aerial or satellite images, which provide powerful geospatial data, particularly by their capacity to visualise changes over time.

For example, a 2D satellite image of the Caspian Sea, which you can see here back in 2006 shared by the NASA Earth Observatory, can be converted into temporal data by being georeferenced using GIS.

The process of georeferencing use to be quite difficult and time-consuming, but there are now GIS tools which can make this process a whole lot easier and more accessible.

One of those tools is media layers and it's a GIS tool which enables us to georeference other layers quite easily and we can then visualise changes over time, including, of course, the impact of climate change.

In the animated image you see here, the Caspian Sea 2D satellite image from 2006 has been georeferenced with media layers so that we can compare it with more recent imagery.

Now one key impact of climate change on the Caspian Sea is that the prevailing increase in air temperatures has led to increases in the temperature of the water in the Caspian Sea, so more of it's evaporating than did before, and that in turn is reducing the water level in the Caspian Sea.

We can actually see this clearly in the animation, especially along the Northern Caspian Sea coastlines, which have changed significantly.

On the eastern side, there's a large inlet of the Caspian Sea known as Sor Kaydak and that's dried up completely.

Consequently, important ecosystems all around the Caspian Sea are being severely damaged or even lost altogether.

Let's just check up on a couple of learning points so far.

Of the options you can see here which impact of climate change on the Caspian Sea is effectively visualised by using a media layer? You may wish to pause the video here while you have a little think about that.

So the correct answer is B, sea level fall.

Which kind of goes against what we might normally think.

We might often associate climate change with sea level rise, but with an inland sea, the issue can often be one of sea level fall, and it certainly is with the Caspian Sea.

For our second check, which term describes the process by which a media layer is aligned with another layer? You may wish to pause the video while you have a little think about that.

Well done if you selected C, georeferencing.

That's the process by which information is tied to a particular location, also known as geolocation.

Now let's consider how we can apply the media layers tool to visualise the impact of climate change in cold environments.

When we think of cold environments, apart from the polar regions, we must also consider the high mountain ranges such as the European Alps.

These cold environments contain many land-based glaciers and in the European Alps, they tend to be found in countries such as France, Switzerland, Austria, and Italy.

One very good way to use media layers in GIS is to visualise the impact of climate change on land-based glaciers.

And one of these land-based glaciers in Switzerland is the Trift Glacier.

It has the dubious distinction of being known as the fastest retreating land-based glacier in the world.

This is a 1971 photograph, the black and white photograph you can see here of the Trift Glacier, and it shows a substantial north facing corrie glacier back in the day.

So what's happened to the Trift Glacier since 1971 and how can GIS help us to find out? Geospatial data has been used here by Mary Leibundgut for Swisstopo, and that's the abbreviated name for the Swiss Federal Office of Topography.

She's used it to create a 2D map of the changing extent of the Trift Glacier, and what Mary did was use lines which show equal points in time called isochrones, and they show the changes in the Trift Glacier extent from the middle of the 19th century right up until 2020.

High-quality surveying of these landscapes in Switzerland has been going on for a long time.

So Swisstopo now has one of the best and longest running records of glacier extent in the world.

And we can see already that the Trift Glacier has retreated quite a long way.

It's left behind a U-shaped valley with a misfit stream flowing through it.

Also, we can see that the corrie glacier has become very small and it's left behind a new corrie lake and that's known as Triftsee, which means Trift Lake.

So how is it possible to use GIS media layers to enhance such an excellent 2D map to visualise and analyse the impact of climate change? Let's see how that can be done in the following video clip, which provides a step-by-step guide demonstrating how to do this.

We're gonna see how we can use 2D GIS media layers to visualise climate change.

So we need to do that in ArcGIS Online Map Viewer.

Before we do that, we're going to download the image we want to use for our potential media layer.

So we need to go to a browser and type in Trift Glacier since 1864.

So we go to images and look at this one here in Wikipedia.

If we click that and then visit that page, scroll down a little bit and you'll see it again here.

We double click till we see a high-quality image that we wanna use as our media layer.

So we save the image that we're going to use shortly as a media layer.

We just need to remember where we saved it, of course.

Next we go back to map viewer and what we need to do before we add the media layer is find the area where the media is going to be located.

So we're gonna search that here in the search panel and I'm gonna type Triftsee because that's the lake which is featured in the map.

So click the Triftsee that's associated with Switzerland, the code is CHE and we go straight to it and we're now ready to add our media layer.

So we need to tell the map where to find the image that we saved a few moments ago.

So we click your device and we look for the image that we saved, and here it is Triftglacier_since_1864.

So we double click that to load the image as a media layer that we're going to need to align in a panel called Add media layer.

Now the next steps are a little bit fiddly, but we have to use these image handles, especially the corner ones, to make the image the correct size to match the map underneath.

We can also make our image a little bit less visible or more visible by using this transparency slider here.

That can come in very handy.

So I'm gonna place it around about there about quarter of away, and we're just gonna zoom out just a little bit and then I'm gonna stretch the image until I can see that the lake is more or less the same orientation and alignment as the lake on the map.

So as I say, this can be a bit fiddly, but it can also be quite satisfying.

It's a bit like doing a sort of jigsaw puzzle really.

So you can see that now and I'll just make my lake a little bit more visible for a moment.

And don't worry if you don't make it exact, it's an approximation, but this is georeferencing in action, so it's a very important skill for us to learn.

I probably need to make it a little bit bigger.

And it's important to use the corner points because that keeps the overall orientation of the image more accurate than if you use the sideways once.

So we're nearly there.

You can see it's a bit fiddly.

You can do this without a mouse, but a mouse is a very helpful thing to have because it gives you a little bit more control.

So very nearly there, and that's a fairly good approximation.

So if I've got to that stage, I'm going to click Update and close.

Then we can check our georeferencing using the transparency slider to show the media layer against the base map underneath.

A useful thing to try at this point as well is to change the base map.

So if we change it, this case, to imagery and then we can use the transparency slider to check our georeferencing against that.

And we can see once again, it's a pretty good match.

So now's a good time to save our work.

So we click Save and Save as and we're going to call this map Trift Glacier.

I'm gonna put DEMO, which you don't need to do.

Just to show that I'm demonstrating this, and I'm gonna save that.

And the next time I make any changes and save that, I won't have to give it a new title, it will already be saved.

We're now in a good position to use our georeferenced media layer to do some analysis to see what's happened with regard to climate change and Trift Glacier.

To do this, we're going to check in the layers panel.

We've got the properties on show.

We do, but if we didn't, we could just click show properties there on the right.

Then we're gonna hide the layers panel and look for the map tools button on the right and click that.

The first tool we're gonna use is measurement and we're gonna measure distance, which is the first icon.

And we're gonna measure in small steps, the distance from the 1864 extent right up to the 2020 extent.

So we're gonna follow the valley as best we can.

If you follow the river, it's quite a good idea, and what we can do is make sure we're going up the middle of the valley that way.

And if we then follow the route through the lake and then up towards where the 2020 extent is.

I'm taking these small steps each time.

And when I've reached the end of that transect, I double click to see what distance is and we can see it's around about four kilometres.

In a similar way, we have another tool which measures the area of ice that's lost.

So we look at the blue line, which is the boundary of the 1864 glacier going back to the yellow line, which is the 2020 boundary, and we can approximate the area of ice that's been lost.

So again, it's a stepping technique.

We just go around the area, and it doesn't matter it's not perfect.

And you can see it does seem to be going the wrong way, but actually isn't.

You'll see what happens when we get to the end.

So we're going inside that line there.

I'm doing this very, very roughly.

I'm following the inside of the 1864 glacier there.

Cutting a few corners.

You can do it much better than I can.

I'm absolutely sure of that.

So what we're doing is finding out the area that's been lost due to climate change and getting very nearly there.

I'm just following that line up the other side of the glacier.

And when we get to the yellow line, I'm gonna go along that just to get some idea.

I could go a little bit further over, but I'm not gonna do that.

Just got to there.

So we get roughly some idea of how much area's been lost.

So we double click and find that the area of ice that's been lost at 2.

81 square kilometres.

Now georeferenced media layer already proven to be pretty useful.

We can extend its use and make it even more powerful by saving it as a media layer.

So we click layers, then the three dots, Save as, and we're gonna save it as Trift Glacier ML.

ML standing for media layer, and then we can use that in other maps and apps.

You'll soon have the opportunity to practise using a 2D map of the Trift Glacier to visualise and analyse the impact of climate change.

But first of all, let's just check up on a couple of points from the demonstration.

When adding a media layer, which tool of the following choices can help check the accuracy of the georeferencing process? You may wish to pause the video here and have think about that while you choose your answer.

So the correct selection tool to help check the accuracy of georeferencing if you are adding a media layer is transparency slider, answer C.

It can be a great help to keep checking back that the media layer has been correctly georeferenced.

Our next check is using some icons.

When using ArcGIS Online Map Viewer, which of the icons you can see here, A, B, C, or D represents the measure area tool? You may wish to pause the video here and have a think about that before you answer.

The correct selection is the icon shown in B, which represents the measure area tool.

It's not A, which is measure distance or C, which is map tools or D, which is save as.

Hopefully, you got that right.

Now for the tasks which are gonna help you to use 2D GIS media layers to visualise change.

Task one guides you through the steps you need to add media layers to create a 2D georeferenced overlay.

Task two guides you how to use map tools to analyse the results of your media layer work in task one.

So pause the video now to take some time to do task one and two and when you're ready, press play to obtain some feedback on these tasks.

We'll see you on the other side of the tasks.

Hopefully, you were able to undertake those tasks effectively.

For task one, you had to use media layers to create a 2D georeferenced overlay of the Trift Glacier since 1864.

So your visualisation should have looked something like this.

Now using media layers can be quite challenging at first, so it's worth persevering until the skills that you need become more fluent.

If you want to fix any errors and improve the georeferencing, you always click the button called edit place media, the blue button you can see here, and then use the corner handles to resize and align the image and the transparency slider to check everything before saving via update and close and then save.

For task two, you needed to use map tools with the newly georeferenced media layer to measure how much of the Trift Glacier had disappeared between 1864 and 2020.

So in answer to the question, how many kilometres or miles of the Trift Glacier has disappeared? You should have found that approximately four kilometres.

That's about 2.

5 miles has disappeared between 1864 and 2020.

Don't worry if your answer is slightly different to this.

Then you need to measure the area of Trift Glacier that's disappeared between 1864 and 2020.

You hopefully found that something in the region of three to four square kilometres that's 1.

2 to 1.

6 square miles has disappeared between 1864 and 2020.

Now let's look at the second learning cycle, which is gonna help us to use 3D GIS media layers to visualise climate change impacts.

So what we're doing in today's lesson is using two linked GIS approaches to visualise climate change impacts.

We're using 2D GIS media layers, then saving the 2D media layers for later use, and then we're gonna be using them as 3D media layers.

Before we do this, let's prepare ourselves so that we know what to look out for.

This is a model or theoretical glaciated upland landscape and it can help us to be on lookout for landforms that appear after glaciation has taken place.

And that's when glacial landforms in upland landscapes become visible due to global warming.

And this has been happening really since the Quaternary Period finished, also known as the Pleistocene.

Some glacial landform are result of global warming such as erosional deposition features.

We're going to find out how 3D GIS can visualise the glacial features created by climate change, particularly around the Trift Glacier.

Similarly, we can look at one of the landforms in detail such as a corrie.

Here's a model corrie in an upland landscape after glaciation.

We can see key features such as the scree, which falls from the steep areas such as the corrie back wall and this is due to freeze-thaw weathering.

We can see how deposits of moraine can build up and help to create a dam for the melt water from the glacier and rainwater that falls after that, which creates the corrie glacier or dam.

So we're going to see how 3D GIS tools can visualise aspects of this, in particular the height and gradient of such a landscape after glaciation.

Then we're going to evaluate the extent to which the Trift Glacier aligns with these models of glaciated upland landscapes.

Let's see how that can be done in the following video clip, which provides a step-by-step guide demonstrating how to do this.

We're going to use a media layer that we've created in the 3D scene to visualise climate change, in particular the landscape around the Trift Glacier in Switzerland.

In order to do this, we need to open the 3D app in ArcGIS Online called Scene.

And when we do that, we're offered the chance of creating a new scene, which we're gonna take.

We're gonna add the media layer that we created earlier on by clicking Add, Browse layers, and in content, we search for the name for it, it was called the Trift Glacier ML media layer and then we're gonna click that to add it to our scene, and then we click Done.

Then we can start to orientate the map using the pan and zoom controls or the mouse control so we can tilt the map, rotate the map in different orientations.

It gives us a very good opportunity to visualise what's a 2D map using contours is actually showing in a true landscape, what the topography means.

To get a really good view of the features that have been left and revealed by climate change, we want to orientate the map so that we're looking at it from the north or northwest.

And we can check that by looking at the little compass here and the black end of the compass is pointing towards north, which means we're looking at it from that direction, which provides us with a really good view of the glacial landforms we're interested in.

Then on the right, we're gonna change the base map using the base map gallery and find imagery.

Then we're gonna go back to layer manager.

And in layer manager, we click the three dots, and we then click Layer properties.

And in layer properties, we can adjust the transparency like this.

So we're now in a position to make powerful comparisons with what the imagery looks like in 3D as well as our media layer that we've added.

And after that we can click Done.

Now it's time to save our work.

So we click Save and we're gonna call this Trift Glacier 3D and we click Save.

And if we need to save it again we just click Save.

Now we're very well placed to analyse this landscape and look at these glacial landforms. So if we just hide the layer manager and maybe orientate our scene so we can see it and get a good perspective on things.

Just move it around a a little bit more.

So what we can see already there, we've got various features we can spot.

So the current glacier is just here.

The snout of it is roundabout there.

It was there in 2020, we can see the yellow line.

May have gone back a little bit since then, of course.

We can compare that with the snout back in 1864 and various other steps along the way in its retreat.

We can see the corrie lake, which is called Triftsee.

It's quite clearly a corrie lip just here.

We can zoom in on that and see the corrie lip.

And then on the other side, we've got the features such as an arete, and we've clearly got something of a U-shaped valley here which is developed because of the truncated spurs and of course that valley has within it this misfit river.

So in other words, a river that couldn't possibly have eroded a valley as big as this.

Another very powerful thing we can do with Scene is make use of the masses amount of elevation data that are embedded in the landscape that we see before us.

So it's invisible but the data is there and what we can do is create a transect to pick up that data to draw an elevation profile.

And we can find the Elevation Profile tool in Scene tools just here.

In order to do that we're going to untick layers and line and leave ground ticked.

And then we're gonna draw the transect line from the top of the glacier to beyond the 1864 extent.

So we just click in steps along the route and I'm gonna try and follow the route down the middle of the valley.

So we're going from the glacier and you can see the elevation profile emerging.

So we're gonna go down the back wall of the corrie and through the middle of the corrie lake, the Triftsee.

Then we're gonna try and make our way over the lip of the corrie and into the misfit river, making our way down the valley as far as we can to the 1864 extent of the glacier.

I have to move them out just a little bit further and then we can go and double click to complete the elevation profile.

So the elevation profile has appeared, and if I move the cursor along the profile, you can see where we are on 3D scene.

One thing that's slightly misleading about this is that the data isn't always accurate for bodies of water.

It's likely that the lake is actually quite deep due to the rotation move to the glacier when it was there creating a hollow.

We can certainly see the lip of the corrie and then the profile cascades down through what is now a hanging valley but would've been a Triftsee Glacier from much larger valley glacier below.

So a good way to use this visualisation is to take a screenshot of the landscape and the elevation profile as well or make a large version of that and then label that using features that we've highlighted already such as the corrie back wall, the corrie lake itself, Triftsee, the corrie lip, and the fact this is a hanging valley.

So what we've seen is that the media layer helps us to appreciate the landscape considerably more than if we we're just looking at the imagery layer because we've got further data and it helps us to understand the processes that have been going on as climate change has gradually revealed this landscape of glacial landforms. Before we move on to the task about 3D media layers, let's just check a couple of learning points.

Select two things a media layer can visualise if it becomes temporal data from these three options, A, B, and C.

You may wish to pause the video here for a little while until you have a think about that.

So the correct two choices are A and C because they're about time, whereas B is just about place.

In our next check is a true or false.

Glacial landforms are not linked to climate change is the statement we want you to think about.

Do you think that's true or false? Pause the video here while you have a little think about that.

Well done if you said false.

But why? What's the reason that this is false? Pause the video again to have some time to think about that.

There are several possible reasons why in fact glacial landforms are linked to climate change.

In many areas, we can only see glacial landforms because the glaciers which created them have melted due to global warming.

They're not there anymore.

They used to be there in the Quaternary Period, but that's finished.

Climate change also causes glacial processes.

For example, it can wash materials away and we can see them as features of glacial deposition, which modify the landscape significantly.

Now for the task linked to the second learning cycle.

Task one will guide you through the steps to add a media layer to a 3D scene.

You'll be very pleased to know that this builds on your earlier good work when you added a media layer to the 2D map, quite a fiddly process.

And the reason is you can use exactly the same layer to drape over the 3D landscape.

This is relatively straightforward.

Your added challenge in task one is to recognise and label some glacial landforms, which have been revealed by climate change.

Task two has two components.

Task A will guide you to use the Elevation Profile tool to visualise the long profile of the landscape in front of the Trift Glacier.

Then task B will be asking you to consider to what extent does the Trift Glacier align with the models of a glaciated landscape in a corrie? We'll see you on the other side of the tasks.

Hopefully, the task went well for you.

For task one where you had to use a media layer to show the Trift Glacier in 3D scene viewer and recognise and label some of the glacial landform.

Your labelled screenshot might hopefully look something like this.

Let's have a look at the labels.

We're showing the Trift Glacier snout in 2020.

We're showing where the snout was in 1864.

We've labelled the Triftsee, which is the new corrie lake.

We've also labelled the corrie lip, which is actually holding back the water, which is in Triftsee.

We can see the current Trift Glacier high above the corrie lake, Triftsee.

We can see an arete, which is a knife-edge ridge in between two hanging valleys.

And we can see a U-shaped valley with the very tiny stream flowing through it.

That's much too small to have eroded the valley.

So we call it a misfit river or misfit stream.

For task 2A in which you had to use the Elevation Profile tool to visualise the long profile of the landscape in front of the Trift Glacier, your labelled screenshot might have looked something like this.

We can see the plucked corrie back wall where you would get a lot of freeze-thaw action.

We can see the hanging valley beneath the corrie.

We can see the corrie lip quite distinctively there.

You can see a pile of moraine, which is gonna hold back the water in the corrie lake.

And the elevation profile doesn't show this, but you could add in if you want to to shade the actual lake.

Finally, for task B, you were asked to consider the extent to which the Trift Glacier aligns with the models of a glaciated upland landscape in a corrie.

Perhaps you had ideas similar to these.

Jacob pointed out a range of glacial landforms in common.

"The glacier and model both show how climate change reveals aretes, truncated spurs, a U-shaped valley, hanging valleys, misfit river or misfit stream and a ribbon lake." Sofia spotted that "The corrie elevation profile is well aligned and we can visualise the back wall and the corrie lake damned by the corrie lip.

All of these, of course, are revealed by climate change." Good point.

And Lucas adds that "Climate change is melting the Trift Glacier rapidly, but it's still present above the corrie, so the glacial landform are still being created under it." Yes, indeed.

Glacial processes are not a thing of the past.

They're going on right now.

Good point by Lucas.

Well done.

We've covered a very wide range of GIS knowledge and skills and I highly recommend that you return to those to practise them until those skills become fluent.

Let's summarise the learning with these key points.

First of all, climate change impacts can be visualised and analysed and we use geospatial data and we can see how things change over time.

It can also be very useful to use georeference data such as maps or aerial or satellite images using the GIS tool, which we call media layers.

The configuration of media layers usually takes place on a 2D map.

This is a lot easier, but it can be saved and then used for even more powerful applications in 3D maps.

GIS tools can be used to support analysis of media layers including measurement tools and the Elevation Profile tool.

So well done for some excellent work using some quite challenging technical GIS knowledge and skills.

Hopefully you found this learning about GIS useful and interesting and I look forward to seeing you in future lessons.

All the best and bye for now.