Lesson video

Hello, my name is Mrs. Grey, and I'm so excited that you've decided to join me to learn Geography today.

Today's lesson is in our unit of "Cities: What are they like to live in?" And the title of today's lesson is "GIS: Visualising and analysing the growth of cities." By the end of the lesson today, you will be able to use GIS to visualise and analyse the growth of cities around the world.

There are some keywords that we'll come across in today's lesson.

They are megacity, Human Development Index, or HDI, and basemap.

A megacity is a city with a population over 10 million.

Human Development Index is a composite measure of development that gives a score between 0 and 1 based on indicators of health, education, and income.

And basemap is a background map or satellite image you can choose in GIS that lets you add other layers of information on top.

Today's lesson is split into two learning cycles: the first, visualising the cities of the world, and the second, analysing the growth of cities around the world.

So let's take a look at our first learning cycle, visualising the cities of the world.

The proportion of people living in urban areas has risen over time.

What are some different ways that we can visualise this? So we could look at a line graph.

We could look at how the rural population and the urban population has changed over time.

We could also look at a GIS.

We can look at a map here, and that swipe function shows the change between 2020 and 2024.

So there are a few different ways that we can look at change over time.

We can look at a line graph and numerical values of change over time, or we can also look at a map and actually visualise physical changes to the landscape over time.

The rise in the world's urban population has led to an increasing number of cities and a growth in existing cities.

In 1950, there were two megacities, Tokyo and New York.

By 2020, it was estimated that there were 39 megacities, so a big increase.

Now, GIS allows us to visualise the location of cities and megacities around the world, and we're gonna have a little look at how to do that now.

<v Instructor>In this video,</v> we are going to use the ArcGIS Geography Visualiser to visualise the major cities of the world.

Now, to do this, the first thing I'm going to do is change the basemap.

So we've currently got an imagery hybrid map on the screen, and that combines satellite imagery with the borders of the countries.

We call that a hybrid map.

I'm going to change that, so I'm gonna come to the bottom toolbar.

I'm going to click on the Basemap, and I'm going to click on the Charted Territory Map.

And that just makes it a little bit easier to see where the different countries are and also gives us lots of reference points by having these lines of latitude running around the world.

I'm then going to add a layer of data onto the map.

So if I come to the bottom toolbar again, I'm going to click on this Add layer button.

Now, this layer of data I can actually get to in two ways.

I can actually get to it if I click on the open map or if I add a layer.

But I'm going to add a layer, and I'm going to go to where it says Cities of the World.

And we can see what it is, explore how the population of urban areas changes, and we can see where it's come from, the United Nations Department of Economic and Social Affairs.

We can see it's published in 2018.

So, that gives a little bit of information about it.

I'm going to click on the Add button.

And when I do that, you will see that there is a little 1 popped up where it says Map layers.

I can now close this pop-up, and you can see that there's lots of circles that have now come onto this map.

Now, to know what these circles mean, I can come to the bottom toolbar and click Legend, and it shows you what they mean.

So we can see that the size of the circle shows us how big the population is.

So, you know, this size is below 37 million, this size is 28 million, this size 20 million, and so on and so forth.

We can see at the bottom there that the smallest circle is cities over 300,000 people.

So we're not gonna have cities which are below 300,000 people.

So this isn't all the cities of the world.

It's what they term as major cities.

Now, first a few warnings about this map.

I'm going to zoom in on the United Kingdom here.

I've clicked on the United Kingdom, and I've dragged it to the centre of the screen, and I'm now using the scroll wheel of the mouse to zoom in.

So, we can see here, for example, there's Plymouth, and there's no red dot there, and that's because Plymouth, it's a pretty big city, but it's under 300,000 people.

So it is important to remember that that's where this starts.

It's really important on these maps as well that we actually make sure that the data is valid.

So there's often slight issues with data that we need to be aware of, and I'll show you an example here.

If I zoom in, and I'm going to zoom into this area around Leeds and Bradford, and you'll notice that there's a red dot around Bradford here but not Leeds.

Now, I know that Leeds is a pretty major city, over 800,000 people, those estimates for the population of Leeds, and yet it's not on.

Bradford is also a big city, maybe around 550,000 people, and there is a circle there.

And if I click on this, you can see that it's actually given me a population, but it's actually said West Yorkshire.

Now, West Yorkshire's a county.

So what they've done here is basically added the population of multiple cities and, you know, wider area to come up with one city.

Now, that's unusual.

It doesn't normally do that.

But it's just important to see some limitations of the data so that when we draw conclusions, we know that we have to understand the limitations of our conclusions and some of the problems that we might have to think about when evaluating our data.

The other issue when we're looking at population is thinking about this figure as actually being, you know, try and decide how accurate the figure is.

So if I take this example here, if I click on Manchester, we can see that there's a population here of over 2.

7 million people.

So that's a really big area.

But the question is is where does Manchester start and where does it stop? Now, that figure of 2.

7 million people is the Greater Manchester area.

It includes places like Stockport.

If I was to move that boundary in, I could actually say that Manchester's only got around half a million people.

It just depends about where I decide the outskirts of Manchester are.

Often, this becomes a problem where, like Manchester, we had a place which has expanded over time and has actually merged with other towns.

So, again, when we look at these populations, we have to understand there are problems or decisions that have had to be made to decide about where the boundaries of the cities are, and that is going to affect our population figures.

And that often means we often get different population figures for the same place.

However, having said all that, this is a really useful map to show us lots of information about major cities around the world.

And what we can do is we can describe where cities are, and that's maybe cities over 300,000 but also maybe the megacities over 10 million, by looking at the map and examining patterns.

We can look at maybe the city the furthest south in the world to see, you know, how far south or north cities stretch.

So for example, this city down here is Christchurch, and we can see, you know, population around 400,000 now.

It's just north of 45 degrees south.

And we can see that we don't have major cities south of that line.

That's largely because of the lack of landmass there.

But it gives us a point that we can then describe.

Now, if we look carefully, there is no city further north than this city.

So if I click on this, this is Arkhangelsk in Russia.

And if I zoom in, it gives us the lines of latitude, which help us describe where it is, and we can see it's just south of 65 degrees north.

So we can say that we don't really get major cities north of 65 degrees north.

We can also look for these really big circles to see where the megacities are.

And if we click on them, we can see just how big they are.

So this is Tokyo in Japan, and we can see a population of over 37 million.

Megacities are defined as populations with over 10 million, so this is definitely a megacity.

And we can see from the map, for example, that we have a concentration now of megacities in China and India.

So, what I can do is I can zoom into these countries.

And I could maybe count the number of cities, I can count the number of megacities, I could find out what they are.

And this allows us to visualise the cities of the world and describe the geographical patterns of where cities can be found and where megacities can be found.

<v ->Our first check for the lesson now then.

</v> Different sources may give very different population data for the same city.

This could be because, A, people may move in and out of the city, B, children are not always counted in population data, C, the boundary of a city can be defined differently by different sources.

So have a little look at that question again, pause the video, write down your answer, and then come back and let's see how you got on.

Okay, how did you get on? Different sources may give very different population data for the same city.

This could be because, C, the boundary of a city can be defined differently by different sources.

How did you get on? Well done.

Another check then.

What do the size of the circles on the major city represent? So look at this map and the circles and the major cities, and what does the size of them represent? So pause the video, write down your answer, and then come back and let's see how you got on.

Okay, how did you get on? What do the size of the circles on the major city represent? And the answer is the population size of each city.

Did you get that? Well done.

So our first big task of the lesson now then.

So the first thing you need to do is open the link.

Then you need to complete the following tasks.

Click on Basemaps in the bottom toolbar and change the map to Charted Territory Map.

Then click on Map layers in the bottom toolbar and add the Cities of the world layer.

Look carefully at the distribution of major cities around the world.

And then choose one country from each continent that has a significant number of major cities and investigate how many major cities and megacities there are within the country.

The second task, complete the table as you investigate one country from each continent, other than Antarctica, and leave the final two columns blank.

So in the first column, you're gonna write the country.

In the second column, which continent it's in.

Then you're gonna write a number, a number of major cities, and then you're gonna write the number of megacities.

And in the next column, you're gonna write the name of the largest city and then leave the last two columns blank because we're gonna fill those in later in the lesson, okay? So you've got a nice big task to do there.

You need to click on that link, follow the instructions step by step, and then fill in the table.

So pause the video while you complete that, and then come back and let's see how you got on.

Okay, how did you get on? So the map of the world cities that you used to visualise major cities around the world should look a little something like this.

And then your table should look similar to this.

Now, you may have chosen these countries and that might be a coincidence, or you may have chosen different countries.

It doesn't matter as long as your table looks similar to this and you've put the right bits of information in the right column.

So for example, for the continent of North America, you might have chosen the USA.

The USA has got 65 major cities and 1 megacity, and the largest city is New York City.

And then each follows on for each of the different continents.

And like I say, you might have these exact countries.

There's lots of different countries that you could have chosen, so it might be different.

As long as you've got the country, the continent that it's in, you've got one from each continent, then the number of major cities, the number of megacities, and the name of the largest city.

How did you get on with that task? Well done.

So now we're gonna move on to our second learning cycle, which is analysing the growth of cities around the world.

It is important to ask geographical questions to help guide our research.

What questions could guide our research on the growth of major cities? Now, Jun suggests, "In which continent are cities growing most rapidly?" Brilliant question for us to investigate.

Sofia says, "How does a country's development affect how rapidly its cities are growing?" Another really, really good question.

Can you think of any questions that we could ask to help guide our research on the growth of major cities? Now, the Geography Visualiser can be used to analyse and to compare growth rates of major cities around the world, and we're gonna take a look at how to do that now.

<v Instructor>In this video,</v> we are going to use the ArcGIS Geography Visualiser to analyse the growth of major cities around the world and compare this growth in countries from different continents.

Now, to do this, the first thing I'm going to do is I'm going to change the basemap.

So I'm going to come to the bottom toolbar, and I'm changing it to a charted territory map.

And that's just so that we can see the countries a little bit easier.

I'm then going to add a data layer, which is major cities.

So if I click Add layer, and then I click on Cities of the World in the pop-up and close this, we can now see the cities, major cities around the world.

And remember, these are cities with over 300,000 people in them.

Now, this layer in the Visualiser has a very useful tool, and that tool is if we click on the proportional circle, and you remember, the circles give us cities of different populations, if we click on the circle, it actually tells a little bit more about each individual city.

So we can see here that when I've clicked on New York, it's actually brought up a graph that I can hover my mouse over and I can see the growth in population over time.

And this is for New York in the United States.

And I can scroll down, and it'll tell me the actual data it's using to show the graph.

But I can look at this trend, I can see it's increasing population at a relatively consistent but steady rate.

And it's gone from just over 14 million in 1960, and it's gone to close to 19 million by 2020.

Now, you can see there that I chose New York.

That's the largest population in the United States.

And what I can now do is I could go to maybe another country around the world in a different continent, and I can click on that circle to find out more about the biggest city in that country.

So, let's say I go over to Africa and I could choose a country like Kenya, which is in the east of Africa.

I can choose the biggest city, so in this case, it's Nairobi.

I can click on it, and I can look at the population growth there.

And what you can see, as you can see here, that it's quite a big difference from New York.

In 1960, it's close to 300,000, but by 2020, it's 4.

7 million.

So it has a much more rapid population growth.

So, what this enables us to do is compare countries in different parts of the world, but we can also think about the level of development of these countries.

So we could also take into account the Human Development Index, for example, which is a measure of how developed the country is.

It takes into account the education of its citizens, the health of its citizens, and the overall economy, the income of its citizens.

And it gives an overall figure.

The higher the figure, the more developed the HDI suggests that country is.

Now, the United States is a very developed country.

It's got a Human Development Index score of around 0.

94, whereas Kenya, it's got a Human Development Index around 0.

63.

So, big changes in where they are in the world, but also in terms of level of development.

Now, it would be useful to be able to see that development layer, maybe as another layer on this GIS, but unfortunately, the Geography Visualiser does not have a layer showing the Human Development Index.

So I can't switch between maps to compare very quickly the cities around the world with the Human Development Index.

So, potentially there, that's where you may decide that actually, I'm going to use a different GIS programme.

Now, ArcGIS has also got a more sophisticated Map Viewer application which allows you to upload some of your own data and choose from a wider range of map layers.

So it's always important to evaluate whether the geographic information system platform is going to do what you want it to do.

However, it's quite easy for us to find out Human Development Index.

So it is something that we can keep in mind as we are analysing the major cities of the world.

And once we've done a country in Africa, we might go to a different country, maybe Germany in Europe.

And we can click on that, and we can analyse the population here and then maybe go to a different country.

Let's go to Lima in Peru in South America and again analyse the population there.

And by analysing how major cities have grown around the world, it starts to allow us to come up with some forms of conclusions about where major cities are growing rapidly and where they are staying at the same population or growing more slowly.

And we can maybe use our geographical understanding to help explain why that might be the case.

<v ->Another check for us now then.

</v> The Human Development Index, or HDI, is a measure of, A, health, education, and income, B, health, employment, and income, C, health, education, and the environment.

So pause the video, choose your answer, and then come back and let's see how you got on.

Okay, how did you get on? The Human Development Index, or HDI, is a measure of, A, health, education, and income.

Did you get that right? Well done.

Now, geographers often use their prior geographical knowledge to suggest reasons for spatial patterns.

Use your prior knowledge to suggest why Nairobi is growing more rapidly than Berlin.

Now, this is some prior knowledge that Lucas has, "I know that Kenya has a lower HDI than Germany.

I know that Kenya still has a lot of people working in farming.

I know that Germany has a lot of industry, like car factories, and these have been around for a long time." So this is the prior geographical knowledge, the information that Lucas already knows.

How can we use this to suggest why Nairobi is growing more rapidly than Berlin? And this is what Lucas has said, "I think that Berlin has grown in the past, and so a lot of people in Germany will already live in urban areas.

Kenya has a lot of people who live in rural areas that may want to move to Nairobi, especially if there are a growing number of jobs." Brilliant, a brilliant use of prior knowledge there to suggest some reasons for growth.

Well done, Lucas.

Another check for us now then.

True or false? Most major cities in Europe are growing faster than most major cities in Africa.

Is that true or false? So pause the video, write down your answer, and then come back and let's see how you got on.

Okay, how did you get on? Most major cities in Europe are growing faster than most major cities in Africa.

Is that true or false? It's false.

But why? On average, major cities in Africa are currently growing much faster than cities in Europe.

This is because in Africa, birth rates are higher and more people are moving to cities in search of jobs, services, and better living conditions.

Did you get that? Well done.

So our next task of the lesson then.

You're gonna open the link for the Geography Visualiser again.

Then complete the following tasks.

So click on Basemaps in the bottom toolbar and change the map to Charted Territory Map.

Then click on Map layers in the bottom toolbar and add the Cities of the world layer.

Then click on the proportional circle for the largest city in each of the countries investigated in Task A.

Examine how the population has changed over the last 60 years.

Then you're gonna complete the final two columns of the table from Task A.

Use this link to find the HDI of each country.

So you're gonna find the HDI of each country, and you can use the link that's on here, Our World in Data, to get that information.

And then the final column is a description, growth rate of the largest city, and you're gonna use that using the Geography Visualiser.

The final task, use your prior knowledge to suggest reasons for the differences in population change between two of the cities you have studied.

So pause the video, go back through and make sure you follow each instruction step by step, fill in the table and then answer this final question using your prior knowledge, and then come back and let's see how you got on.

Okay, how did you get on? So your map of world cities that you used to analyse growth rates should look similar to this.

The final two columns of your table may look like this.

So we used the USA in North America as our example before.

The HDI is 0.

938.

We found that information using the Our World in Data link.

Now, the HDI's gonna be different for all the different countries that you've chosen.

And then a description of the growth rate.

So the USA, the largest city, New York City, is growing slowly as it is a mature, developed city.

So your descriptions are gonna be different based on which countries you've chosen for your table.

The final task, use your prior knowledge to suggest reasons for the differences in population change between two of the cities you have studied.

Your answer may have included: so for this answer, we've looked at New York and Nairobi.

And I'll talk through what we've written here, but you will have something similar to this, maybe a little bit different depending on which two cities you've chosen.

I think New York and Nairobi have different population changes because they are in different types of countries.

New York is in a high-income country where most people already live in cities, so there isn't much rural-to-urban migration.

The population grows slowly because birth rates are low and the city is already very developed.

Nairobi is in a low-income country, so lots of people move there from the countryside to find jobs, education, and better services.

It also has a higher birth rate, so the population is growing much faster than New York's.

How did you get on with your task? Which two cities did you choose, and what were the differences? Did you use your prior knowledge well to be able to give some suggestions and reasons for those differences? Well done.

So we're at the end of our lesson now on "GIS: Visualising and analysing the growth of cities." Let's have a look at some things that we've learned today.

GIS can be used to visualise cities around the world.

India and China now have a large number of megacities.

Cities with a lower HDI often have faster growth rates than cities with a higher HDI.

GIS can be used to analyse the growth of different cities around the world.

Thank you for joining me for today's Geography lesson.

I've really enjoyed it, and I hope you have too.

I look forward to seeing you next time.