Lesson video

Hello, my name is Mr. Conway.

I'm very pleased to have the opportunity to guide you through today's geography lesson.

The emphasis is going to be on using GIS or geographical information systems. So let's get started.

Our particular focus in this lesson is using GIS to support our study of global biomes, and it's going to be within the unit ecosystems, biomes and the biosphere.

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

And by the end of today's lesson, the hope is that we'll be able to use GIS webmaps and filters to visualise the distribution and characteristics of global biomes.

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

So the keywords for today's lesson are as follows, geographic information system, webmap, spatial distribution and filter.

Let's look at those in a little bit more detail.

A GIS or geographic information system is a computer system that captures, analyses and displays geographic data to help understand spatial patterns.

A webmap is a digital map, which is available online.

It will usually be interactive or it can be created or saved by the user online, or what we sometimes say, in the cloud.

Spatial distribution means the spread of information, that's data, across an area, creating spatial patterns, which geographers attempt to describe, explain, and analyse.

And a filter refers to a GIS technique, which enables the selection of some data in the GIS layer to visualise spatial patterns more clearly.

Notice how often the word spatial appears in these keywords because it's a crucial term that we often use in geography.

Today's lesson about how to use GIS to visualise the distribution and characteristics of global biomes will comprise two learning cycles.

The first learning cycle addresses the question, how can we map global biomes using GIS layers? And the second learning cycle addresses the question, how are filters and transparency sliders used? So we're going to look at the first of these learning cycles now, which is how can we map global biomes using GIS layers? Let's remember, a geographic information system, or GIS, is what we use to visualise spatial data, which has been stored electronically, and that's to create a webmap.

A webmap's distinct from a conventional paper map because it will normally be viewed online.

In order to locate places, GIS must use decimal degrees of latitude and longitude to precisely georeference the spatial data.

And here's a simple example of using decimal degrees where a piece of data about the Californian city of San Francisco, with a population of 4.

5 million, has been georeferenced using decimal degrees that can be recognised by GIS.

So San Francisco is at 37.

8 degrees latitude.

Notice, that's plus 37.

8 and minus 122.

4 degrees of longitude.

The latitude number is positive and that tells us it's in the northern hemisphere.

If it was southern hemisphere, the latitude number would be negative.

If we then look at San Francisco's longitude number, we find that that's negative and that tells us it's in the western hemisphere.

Eastern hemisphere numbers, on the other hand, would be positive.

There are many different GIS options, which can be used to map spatial data, but we're going to use ArcGIS Online Map Viewer and that's to visualise global biomes.

One reason for this is that the subscription to ArcGIS Online is available free to all schools.

So for this lesson, everything we're going to do can be done whether or not you're logged on to ArcGIS online.

However, if you're not logged in, you'll only be able to save your work as screenshots.

So I expect you're asking a similar question to Sam.

How do we add spatial data to a webmap? Let's find out.

We'll be using the ArcGIS Online Map Viewer.

So I'd like to point out a couple of basic things about how we use it.

In spite of its humble name, Map Viewer isn't just for viewing webmaps; it's also possible to create them.

So it has two vertical toolbars with various useful control buttons.

The dark coloured toolbar on the left is known as the contents toolbar, and that helps us select the items of spatial data that we want to visualise.

The light coloured toolbar on the right is known as the settings toolbar, and that provides all kinds of tools for configuring the spatial data, such as the way we want to visualise the spatial data itself.

The following video clip is gonna provide you with a step-by-step guide, demonstrating how to use the toolbars in Map Viewer to visualise spatial data about global biomes and a guide about how to use this is going to be provided in task A.

The webmap we're going to use for this is ready made, which means it's preloaded with layers about biomes.

Let's see how we can use the toolbars in ArcGIS Online's Map Viewer to add global biomes data.

We're starting off with the topographic basemap, which we can see in the basemap gallery by clicking the left vertical bar.

So we can see the range of basemaps.

And you'll see the topographic layer is shown there by default.

We can always change this basemap to an alternative, such as imagery and that shows satellites and aerial imagery from all around the world.

And we can also zoom in and out on any of these basemaps to show more detail, like this.

So this particular map is preloaded with layers and we can look at those now by clicking the layers button in the vertical panel.

And that reveals a set of layers that are all connected with biomes.

Let's take a look at the first one, which is called World Biomes ALL and if I click the visibility little eye there, it'll appear, and then I can shut the layers panel so we can have a good look at the map.

If we're not quite sure what the layer colours mean, there's a legend button we can press here to get some idea of what's going on with those colours.

So we can see here we have all the biomes shown, going from desert to grassland, lake, rock and ice, taiga, temperate forest, tropical forest and tundra.

We can also click on the layers to get some idea of which layer we're looking at at any time.

That's quite useful.

And if we want to zoom in on any particular area, we can do that as well.

As before, we can just zoom in.

So for example, here we're looking at the boundary between the desert biome, in this case, it's the Sahara Desert in North Africa and the biome just to the south of it, which is grassland.

Before we go on to look at the distribution of the biomes in a bit more detail, let's just return to think about the basemaps we're using.

We talked about it a little bit earlier on, but if we look at the basemap gallery, we can see why this is important.

So, for example, we can add details in terms of labels to the map, which is obviously gonna be useful so that we know where we are by adding Imagery Hybrid instead.

So we're changing the basemap to Imagery Hybrid, and that shows us lots of details about where places are in the world.

And once again, if we zoom down, we can start seeing lots and lots of detail and the detail will improve for anywhere you go in the world.

If I just zoom in like this, you can see more and more place names, for example, and borders, including internal borders.

That's quite a lot of information for us to deal with.

So perhaps we don't want that.

So if we go back to imagery but then change to another layer, let's go for another layer.

This time we're gonna go for one called Light Grey Canvas, but you can see it's very pale and it's more difficult to see the colours of the biomes.

So we could change it perhaps to Dark Grey Canvas.

And with this layer, the biomes really stand out much more clearly.

Another alternative might be to try a basemap called Oceans.

Although the oceans layer can be very useful for many purposes, in this case, it doesn't really have enough contrast with the terrestrial biomes, a little bit like the Light Grey Canvas problem.

So perhaps Dark Grey Canvas is a good one to choose.

Or indeed, if we go back to imagery, which we started with.

So different basemaps can be used to improve the visualisation of the data layer we're looking at.

So in this case with biomes, we found that it helps to have a layer underneath, the basemap underneath that provides contrast to improve the visualisation of the data that we're interested in.

Soon you'll have a chance to use the webmap in the same way as you saw in the video clip demonstration.

The task for lesson provide all the steps you need and you can always refer back to the video if there's anything you want to check about what those steps look like or just follow along.

But before we do that, let's just check to see if you can recall a couple of points from our learning so far.

Firstly, from the options A, B, C, and D, choose two of them which are characteristics of a webmap.

You may wish to pause the video here and restart it when you've selected your two answers.

Well done if you chose B and C.

A web app is indeed a digital map which can be seen online and it is also a map which users can interact with and add to.

For our second check, now let's look at three different webmaps showing the same data configured in slightly different ways.

Which of these webmaps do you think uses the most effective basemap to visualise the global biomes? Pause the video here and restart it when you've selected your answer.

Well done if you chose B.

Which is the most effective basemap to visualise global biomes? Because it provides much better contrast with the spatial data we want to focus on.

The basemaps in A and C are not so effective for this data because their colours are a bit too pale and too close to what we're trying to look at, and they don't provide sufficient contrast.

Now for the tasks, which are going to help you to use the GIS toolbars in Map Viewer to visualise spatial data about global biomes, as you saw demonstrated in the video clip.

In order to do these tasks, you'll need to open ArcGIS Map Viewer with the link provided.

Sign in if you can and would like to be able to save your work other than by screenshots.

And then complete the tasks to visualise the global biomes.

There are two tasks.

Task one is to add spatial data about global biomes using the content: dark toolbar on the left side of the map view app.

And task two is to evaluate the techniques, particularly the different basemaps.

So pause the video now and take some time to do the task.

So when you're ready, press play to obtain some feedback and we'll see you on the other side of the tasks.

Hopefully the task went well for you.

If something didn't work quite as well as you expected or hoped, it might be because you missed one or two small steps.

Don't worry because GIS can sometimes be like that, but it's always worth persevering.

For task one, you need to add spatial data about global biomes.

So your global biome map should have looked something like this.

If it doesn't look like this, check back on the steps in the video task.

For example, did you remember to click the legend button to show what the different colours mean in order to help you interpret the layer? For task two, which asked you to evaluate the basemaps, were some of your opinions along these lines? For example, Alex found that the popup details are useful to show the different biome types and which ones are next to each other.

Aisha commented that the basemaps with place names can be helpful to show the biomes found in different countries and continents.

And Sofia found that the contrast with darker basemaps, such as Imagery or Dark Grey Canvas, give the clearest visualisations.

Now let's look at our second learning cycle where the focus question is how are filters and transparency sliders used? You'll hopefully recall that earlier in the lesson, I pointed out that the light coloured toolbar on the right-hand side of Map Viewer is known as the settings toolbar and it contains useful GIS tools that can help us to investigate the spatial distribution of global biomes.

The reason why we use such tools is that in any given webmap, there will be several GIS layers.

We can think of each one being a little bit like a sheet of tracing paper with different information on it.

With tracing paper, we'd need to lift or flick through each one, which would be a bit cumbersome.

But in a webmap there are much easier ways to do this.

So we can see the spatial distributions more clearly.

And one way to do it is to switch or toggle the layers or even parts of layers on and off using filters and transparency sliders.

So like Sofia, I'm sure you're very keen to find out how we use tools like filters and transparency sliders.

The following video clip is gonna provide a step-by-step guide, demonstrating how to use filters and transparency sliders to investigate the spatial distribution of biomes.

Let's look at the map again to see how we can investigate the spatial distribution of global biomes.

The webmap contains several GIS layers, which act a little bit like sheets of tracing paper on top of each other and we can use them to look at the spatial distribution a bit more clearly.

One way we can do this is to switch or toggle layers or even parts of the layers, as we'll see, by switching them on and off using filters and things called transparency sliders.

Good question there from Sofia.

How do we use filters? Let's see.

First, we go to the content toolbar and open the layers panel and check we've got the correct layer on.

We can toggle that on and off by clicking the visibility eye.

And just to the right of the visibility eye are three dots and they give us a whole load of other options.

So if I click those and then click show properties, I reveal from the toolbar on the other side, it's called the settings toolbar, a whole load of other things to do.

You can see lots of icons down here.

Now, once I've clicked those three dots to show the properties bar, I can then select something to do with that layer, and I'm going to select filter.

So if I select filter, you'll notice that that panel changes and it says it wants me to add something new.

So let's do that and add something new.

The official name of the layer is Elem_Biome, and it's saying to me, what part of it do you want to show? So I'm saying the bit I want to show is desert.

And if I click that, you can see that that's all that appears.

And I can click the popups and when I click the popups, the rest of the desert is highlighted, and I can hide the layers panel because that's getting in the way a little bit.

So I can see more of the map if I just move that to one side.

So what we've done is taken the other biomes out of view.

We can only see the desert biome, and that's quite useful if we're trying to really concentrate on studying the spatial distribution of just one biome 'cause we've removed the others from our view by selecting just part of the layer, the part that shows the deserts.

And we could do the same with one of the other biomes, such as temperate forests.

And we can move the map around by sliding this because it's a webmap.

And indeed, by doing that, we can then see that temperate rainforests extend throughout Australasia.

That is through Australia and New Zealand.

Let's look at another layer.

We go back to the selection panel and we'll look this time at tropical forests or tropical rainforests.

We put that layer on, filter all the others out, and we can see the distribution of rainforests around the world.

And if we change the basemap, that might help us with our distribution descriptions because we can then see which precise countries rainforests run through because we can see the boundaries there and the names of forests.

So we're not just saying rainforests are in Central Africa.

We can say precisely which countries that they're mainly found in.

Now, apart from filtering, there's one other thing we can do, which is use the transparency slider.

To demonstrate this, I'm gonna put a layer on which'll be a little bit easy to see, which is deserts.

And then we head over to the settings toolbar.

And this time, we're gonna close the filter by clicking that cross, and we're going to find the transparency slider.

And we just basically scroll down until we can see the word transparency, and then we can make the layer more or less transparent.

0% means that it's not transparent, so if we increase the transparency, we can eventually reach 100% where the layer disappears all together.

Transparency could be useful if we want to explore perhaps the physical or human geography underneath the layer.

If we go, for example, to the deserts in southwest USA and northwest Mexico, at the moment, we could just see a load of orange, which is slightly obscuring what's underneath.

So if we just zoom down on that and then use the transparency slider, we can get a better idea of what the landscape is like underneath.

And we can see that there are actually some quite big settlements there, like Tucson.

So that's a useful way to use that.

If I put the layer back and we go to another part of the world, perhaps we go to somewhere in the Sahara.

So if we go to this area of the Sahara here, what we can then see, we can see that the desert actually does reach right down to the coastline.

A lot of people think deserts are only inland, but they're not, they reach right down to the sea.

And this is very important because winds that blow off the Sahara blow vast amounts of dust into the atmosphere, which eventually falls out over the sea, providing nutrients for the ocean, but also for the land around the Caribbean where it fertilises the soils.

It's quite an important source of nutrients.

Having seen how we can use filters and transparency sliders to investigate the spatial distribution of biomes, let's do a quick check on that learning.

Take a look at these three webmaps.

Which of these webmaps has used a filter to visualise desert biomes? Pause the video here if you wish, and restart it when you've selected your answer.

If you chose C, well done.

That's correct.

Only one biome is shown in that map and the shading is clearly that orangy brown colour we associate with deserts.

Let's do another check.

Which one of the following statements is correct? Pause the video here if you wish, and restart it when you've selected your answer.

Well done if you chose D, rainforests do not occur all over Africa.

And this statement is correct because rainforests are restricted mainly to Central Africa and some areas to the east, including Madagascar.

Now take a look at a third video clip, which provides a step-by-step guide, demonstrating how we can use GIS layers but this time to explain the spatial distribution of biomes.

As well as using GIS layers to help us to see where biomes are in the world and to look at their spatial distribution, we can also use them to help us to explain that distribution.

Let's see how that's done.

We scroll down in this map to look at some layers we haven't seen before, and we're gonna put on a new layer called Surface Air Temperature.

This is the average annual temperature around the world.

So if we click that to make it visible, we can see that a whole lot of colours have been added.

We can then look in the legend to see what those colours mean.

And they're shown here in this quite extensive legend, showing the different temperatures, going from really cold, -50 that is, right through here to 34, that's plus 34 degrees Celsius, on average.

And if we click on the map, we can see and pop up information what the maximum and minimum temperatures are.

So in this area, the maximum is 30, going further north from the equator, 25, 20, 15, 10, and then up into the Arctic, -10 is the maximum.

So we get some idea of the temperature and then we can try and make a link with where the biomes of the world are.

Once again, perhaps the colours here are a little bit blurring together, so we can, of course, use the properties.

So if we go to the layer here that we're looking at, that's the Surface Air Temperature and we can show the properties.

And this time, as we've done before, we can use the transparency slider.

So I'm just gonna do that now.

And you can see it just sort of fades them out a little bit, put them back again.

And then it helps us to see the biomes just a little bit more clearly.

I've just made it slightly transparent, just 10%, and it can make all the difference.

So if we just clear the layers panel for a moment to take a look at this and we can see how the layer of air temperatures could help us to start addressing questions, such as which biomes are found in the areas with the highest air temperatures, which biomes are found in the areas with the lowest air temperatures, and why are biome types linked to air temperatures? Notice as well how the lines are not nice and straight.

They're often quite curved and there are reasons for this which you might want to consider.

There could be factors such as altitude, but another one could be proximity to the sea.

We can examine that by checking another layer.

So if we click the layers panel, I'll go down to a different layer.

This time, it's going to be Sea Surface Temperature.

So notice this has changed things a little bit.

Just gonna close the layer panel there.

And we're just going to use the transparency slider with this Sea Surface Temperature layer as well.

So I'm gonna click once again properties, shut the layer panel.

Then I can look at the layer here and you'll see that the red, green and blue roughly correspond to different temperatures.

You have to kind of use intuition with this one to look at the different temperatures.

But broadly speaking, red is gonna be the warmer water and blue is gonna be the cooler water.

And what we can do is look at the transparency slider to see what the relationship is with the location of biomes.

So I'm just gonna just turn that down just for a second.

We go back to the air temperature, go back to the sea surface temperature, and we can see movement of water around the world is actually carrying energy.

There are several places in the world where we can see this, but one in particular affects us.

So if we zoom in on the North Atlantic, we can see that there seems to be a kind of flow of warmer water here and that actually continues right across the Atlantic.

And that, of course, is the North Atlantic Drift Current or Gulf Stream, which is part of what's called the thermohaline circulation.

And the movement of warm water around the world means that you can get climates that are perhaps warmer or more mild than they might be otherwise, such as our climate, which means that we have temperate forests.

But if you go across to the other side of the Atlantic, on the same latitude, we can see taiga or northern forests associated with a much colder climate.

So we're just gonna switch off the Sea Surface Temperature layer and look back at the air temperature.

One thing that is missing from our explanation so far, but we could add it on another occasion, is another key aspect of climate, which, of course, is precipitation.

So if we add a layer of that, that might help us to add further explanation about the distribution of biomes.

Very soon you'll have a chance to use filters, transparency sliders, and explanatory GIS layers, just as you saw in the video demonstrations.

But let's do one last check for understanding.

Which climate factor other than temperature is most likely to determine biome location? Pause the video here if you wish, and restart it when you've selected your answer.

Well done if you selected precipitation as the climate factor other than temperature most likely to determine biome location.

Now for the task which will guide you in the use of filters, transparency sliders, and using other layers to explain the spatial distribution of biomes, just as we saw in the video clips.

In order for you to be able to do these tasks, you need the same webmap we use for task A, which may still be open, but in case not, the link is provided and you can sign in if you want to, and would like to be able to save your work other than by screenshots.

There are three tasks.

Task one enables you to use filter and transparency sliders to investigate the spatial distribution of each biome.

And task two and three guide you to use other GIS layers, which offer explanations for the distribution of global biomes.

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

We see you later on.

Hopefully those tasks went well for you.

For task one in which you used filters to investigate the spatial distribution of each biome, perhaps your findings were similar to Laura's who used filters to see just one biome at a time, and it made it easier for her to see the distribution.

Or Jun who used filters to compare the distribution of temperate forests, deserts and tropical forests.

Or Izzy who used the transparency slide to see what the landscape really looks like beneath each biome layer.

Good idea.

Hopefully you're gonna find time to practise using filters and transparency sliders because they can be really helpful in the analysis of all kinds of spatial data.

If we have a look at task two and three, you're invited to use GIS layers to explain the distribution of biomes.

Your answers may have included ideas similar to these.

For task two, how does surface air temperature influence biome distribution, Lucas found that warmer temperatures are linked to biomes, such as rainforests and deserts, whereas cooler temperatures are linked to biomes, such as taiga and tundra.

For task three, how does sea surface temperature influence biome distribution, Jacob found that ocean currents make some areas warmer or colder than they would otherwise be at that latitude.

For example, the UK has temperate forest, that's due to the Gulf stream, but eastern Canada has the taiga biome and that's due to the colder Labrador Current, even though their latitudes are similar.

Well done.

We've covered a wide range of GIS knowledge and skills, and it's highly recommended that you return to them and practise them so that your GIS capabilities can become fluent.

Let's summarise that learning with these key points.

Global biomes can be easily mapped using GIS layers in webmaps.

GIS layers can help us to visualise the spatial distribution of global biomes more clearly.

The selection of basemaps can improve the effectiveness of visualisation.

And finally, filters and transparency sliders can be used to toggle and fade in and out biome layers, helping to explain their spatial distribution.

So we've made some really good progress with using GIS webmaps in this lesson, and that's excellent work.

Hopefully you've found the learning interesting and useful and I look forward to further learning together in another lesson.

All the best and bye for now.