Lesson video

Hello, my name is Mr. Conway.

I'm very pleased to have this opportunity to guide you through today's geography lesson, which is gonna have a strong emphasis on using GIS or geographical information systems. So let's get started.

Our particular focus in this lesson is using GIS to map the track or tracks of tropical storms, and it's going to be within the unit called, "Weather hazards." Some of the learning about GIS may be new to you, but I'm here to guide you along the way.

So by the end of today's lesson, my hope and our hope is very much that you'll be able to use and configure GIS to visualise the tracks of tropical storms. To help us achieve the outcome, we need to look at some keywords.

The keywords for today's lesson are attribute, pop-up, geo-reference data and temporal data.

So let's look at the definitions.

An attribute is a data value associated with a particular feature or variable measure, and it's sometimes called a field in a GIS layer.

A pop-up in GIS is a read-only display of attribute information or variable information such as text or images or charts, and it's always linked to a particular location.

Geo-reference data is information which has been tied to a particular location, so of course it could be the information in a pop-up, but all GIS maps have to be geo-referenced.

What this means is they've used geolocation with an agreed grid system such as latitude and longitude, and they're usually measured in decimal degrees of latitude and longitude as well.

And our final key term is temporal data, which is any information tied to a particular point in time.

So the data may be time enabled, and if it's also geo-reference, we sometimes call it spatiotemporal data.

Today's lesson will comprise two learning cycles.

The first learning cycle addresses the question, how can tropical storm layers be configured? And the second learning cycle will help us to find out how data for one particular tropical storm can be mapped using GIS.

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

Using GIS apps, we can visualise data about all kinds of things that are happening in the atmosphere, and one of those would be tropical storms. Various kinds of data can be displayed in what are called digital layers, and then we can configure them to improve the visualisation and make things clearer and enable us to analyse what's going on.

In the example here we can see a hurricane that crossed Florida in October, 2024, and it's using satellite imagery, which is sometimes called remote sensing, and the layer of data has been configured to show the temperature of different layers of air.

So the cooler air is shown with cooler colours, sort of light blues and whites, and the warmer temperatures use the range from red through to yellow.

We can also configure data about tropical storms using GIS apps such as ArcGIS online and in their app called Map Viewer, we can visualise the attributes of the geo-reference data about tropical storms. So using apps such as Map Viewer geo referenced data can then be visualised in layers in webmaps.

And you can see an example of a webmap here in ArcGIS Online in Map Viewer.

The data we add can be ready-made layers that other people have made.

The other people could be GIS professionals or geography teachers or students, and then they can be shared.

So such layers that are ready made are viewable and we can configure them as we'd like and we'll see how to do that shortly.

But they're not usually editable.

We can't change the data in them or haven't put data into them ourselves.

On the other hand, we can sometimes create layers ourselves by using data that we've gathered, collected ourselves or obtained from another source.

Then we can configure that data ourselves and of course we can share that.

So we're actually going to see how we could do both of those things in this lesson.

The first thing we're going to do is see how we can add and configure ready-made tropical storm layers to a webmap.

So the following video clip provides a step-by-step guide demonstrating how to do this.

Let's see how we can add ready-made tropical storm layers to a webmap.

We're starting in ArcGIS Online Map Viewer, and we're going to click the base map gallery in the context dot toolbar just here on the left hand side.

I'm gonna change the base map to imagery hybrid because that's gonna suit our work best.

Then we're gonna add browse layers.

So we're going to click add to browse layers and we're gonna make sure we're looking in ArcGIS Online, not my content.

And the layer we're gonna search for is called, "Prominent latitudes and longitudes." You just have to type, "Latitude" Into the search and you should find that as one of the top two layers.

And if we click add, it'll put it onto the map as a new layer, and when we do that, its properties will appear as well.

Then we click the layers panel on the left to show the layer that we've just added.

And in fact, it's more than one layer.

It's got some sub layers which we can reveal by clicking the small arrow.

And we can hide one of the layers by clicking the visibility buttons just here.

And we're gonna click to hide the latitudes and longitudes so that we just show the major parallels and meridians.

Then I'm gonna head back to the browse layers button to search for another layer.

This time is going to be historical hurricane tracks, once again, in ArcGIS Online.

So I typed that into there and sure enough, there's the layer that I need.

I'm gonna click add so that I can see that and it should appear on the map, and it's quite a dramatic sight.

This layer, historical hurricane tracks, shows tropical storms going back a long time to around 1853.

So it's a very big data set.

We're just gonna hide the properties layer by clicking properties over here so that we can see the map a little bit more clearly.

And another thing we're gonna do to make it even better is we're gonna look at the legend for the map 'cause that's gonna help us to understand what the meaning of the colours is.

So if we click legend, the colours reveal the magnitude of the storms at different stages of their tracks.

Now we can explore the map using pan and zoom in the usual way, and this will help us to see what the overall spatial pattern is of the tropical storms and the way in which they compare with the latitude and longitude layers.

In particular, we can see how the most intense activity is concentrated in between the equator and the two tropics, the tropic of Cancer and the tropic of Capricorn.

In the northern hemisphere, we see how the North Atlantic and the Northeast Pacific have many tropical storms. In the southern hemisphere we have a similar pattern.

The Indian Ocean gets a lot of storms, so does the Southwest Pacific.

However, there are exceptions with the South Atlantic where there don't appear to be very many at all.

Just a couple here.

And also in the Southeast Pacific where there are very few, if any, tropical storms. Crucially, one generalisation which holds true is that we don't see any tropical storm activity actually along the equator at all even if we zoom in.

A few storms get close to the equator, but one thing that never happens is that they don't cross the equator.

A key reason for this is that the coriolis force which drives the rotation of hurricanes, is almost non-existent along the equator.

And a final point to make is that as the storms move further north, we see the intensity reducing.

The colour of the lines tends to be a lighter blue, and that's because they're losing energy as they move over the cooler waters to the north and to the south of the tropics.

So we've seen a way that GIS can help us to appreciate the spatial pattern of tropical.

Let's save our work.

We're saving it for the first time, so we click save and save as we're gonna give our map the title of, "Tropical storms" And save it into our content.

It's not uncommon for a map like this where we're using ready-made data to be showing a very large amount of data, what we've called big data.

What we wanna do is to be able to pick out one or two aspects of it so that we can study them.

To do that, we can use something called filters.

So we're gonna see how to do that.

First of all, we go to the layers panel and find the historical hurricane tracks, and we'll see three dots at the end of the layer.

If we click those and then click show properties, the panel on the right opens up, and part of that is something called a filter, which is shown by this symbol here, which looks like a funnel.

So we click filter and we're invited to set a condition for the filter.

So the first condition we're gonna set is for the hurricane's name, and we're gonna click the selection box for the attributes, click name, and then in the selection here, we're gonna see if we can find one.

One we're gonna look for has a nice short name, "Ian" And we can see it's listed there.

So we click Ian, and what we find is that there is more than one hurricane over the years called Ian.

We only want to look at one of them.

So what we can do is set another condition.

We add new, and we're gonna look for the year in which there was a Hurricane Ian.

And in the dropdown menu we typed, "2022" To find the Hurricane Ian which happened in late September, early October of that year.

So having started with a kind of spaghetti of lines of tracks of hurricanes over very, very many years, we're now left with just one that we can look at and study.

So now is quite a good time to save our map.

It's a quick save this time because we've already named it, and we're also gonna open the legend again so that we can easily interpret the symbology for Hurricane Ian.

We can see how Hurricane Ian started as a tropical depression just north of Venezuela, north of Caracas.

It tracked westward across the Caribbean sea staying mainly in the open sea, and then it began to move northwest and eventually as as category three tracked across Cuba just here.

I'll just zoom out so you can see Cuba.

And then it carried on further north and eventually made landfall on the western side of Florida quite near a place called Punta Gorda.

You can see the town Punta Gorda just here.

We zoom out again, the hurricane tracked across Florida doing quite a lot of damage.

Then it went to the open sea over the Atlantic and began to lose some of its power, but it was only at sea for a little while and then it returned to the North Carolina coast near Charleston and then carried on inland and produced quite a lot of rainfall there and eventually fizzled out and died out over the mainland part of the northeast United States, mainly because it lost its source of energy because it was no longer over open water.

And the blue colours tell us that.

Soon you'll have a chance to create maps in the same way as you saw in the demonstration.

But before we do that, let's just check and see if you picked up a couple of key points from the demonstration.

Our first check is what name is used for the icon which looks very like an eye for a very good reason that's used to toggle layers on and off to improve visualisation of spatial data? You may wish to pause the video here while you have a short think about that.

Well done if you chose the visibility icon.

You can use that to toggle layers on and off, and it's quite a common tool that we use if we're trying to show a layer and then maybe reveal another layer beneath it or indeed above it.

Now let's look at this question.

It's a true or false question.

Would it be true or force to say that the occurrence and track of a tropical storm is mainly restricted to low latitudes? Decide if that's true or false, then pause the video if you wish to think about that for a little while.

Well done if you said that this statement is true, but can you explain why it's true? Once again, pause the video to have some thinking time about why it's true.

It's true to say that the occurrence and track of tropical storms is generally restricted to the tropical areas because they rely on warm surface water in the oceans of that area to provide them with their energy.

A good way to think of storms is almost like hungry animals that need food in the same way as we need food, like carbohydrates give us energy.

The oceans north of there are generally just too cold to sustain tropical storms. They're not providing enough energy to generate them or to keep them going for very long.

So in the higher latitudes outside the tropics, the tropical storms that we see in the tropics just aren't found very much.

They're very true to their name.

They operate essentially within the tropics, although they do sometimes drift outside, but they fizzle out when they run out of energy.

Now for the task which will help you to add and configure tropical storm layers as demonstrated in the video clip.

In order to do these tasks, you'll need to open up ArcGIS Online using the Oak link provided, sign in and then click map to open Map Viewer.

There are two tasks, each with two components, where you're going to develop some of the GI skills and then offer some interpretation of the results.

Task one asks you to add and configure a ready-made layer about tropical storms with a follow-up question, "How does the pattern compare with the tropic and equator lines?" In task two, you're going to practise using filters to visualise one storm on the tropical storms map.

Then use the visualisation to describe the track of one particularly famous storm called Hurricane Ian using geographical terms. So pause the video now to take some time to do the tasks and when you're ready, press play to obtain some feedback on those tasks.

So we'll see you on the other side of the tasks.

Hopefully you were able to undertake the task quite well.

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

So don't worry because GIS can sometimes be like that, but it's always worth persevering and going back over to see where you made the errors.

For task 1a, where you had to add a configure a ready-made layer about a tropical storm, the visualisation on your screen should have looked something like this.

Then for task B, "How does the pattern compare with the tropic and equator lines?" You may have noticed that most severe tropical storms develop about five degrees north or south of the equator, and they stay mainly in the tropics.

Exceptions include the South Atlantic and the Southeast Pacific.

Remember, they never cross the equator.

For task 2a, which involve using filters to visualise one storm on tropical storms map leading to task B to describe the track of Hurricane Ian, you may have made similar points to the ones like those made here.

Alex observed that Hurricane Ian started as a tropical depression in the Gulf of Mexico near Venezuela, tracking across open sea.

We may have noticed, as Aisha did, that Hurricane Ian tracked northwest across Cuba as a category three hurricane, making landfall on Florida's west coast as a category five.

And then Sophia considered the end of Hurricane Ian's lifecycle with some good placed detail, saying that it tracked across Florida from east to west and then moved into the Atlantic, making landfall again near Charleston, North Carolina.

Let's look at our second learning cycle.

How can tropical storm data be mapped using GIS? By using GIS apps, we can visualise data about a particular tropical storm.

The Philippines in Southeast Asia is very vulnerable to tropical storms, and it's where the regional name, "Typhoon" Is used, but they're exactly the same as other tropical storms like hurricanes or cyclones.

The particular tropical storm we're going to visualise is typhoon Rai, also known as super typhoon Odette, which was particularly severe in its impact on the Philippines in December, 2021.

Before we visualise the data, let's see what the data actually looks like in a spreadsheet, which is the way most GIS data appears before it's visualised.

Here we see the attribute data about typhoon Rai.

Columns A and B show longitudinal latitude in decimal degrees, which of course are essential to enable us to geo-reference the data.

Columns C and D show the wind speeds in kilometres per hour and miles per hour.

Column E shows the magnitude of the typhoon using an approximation for the Saffir Simpson scale, which is normally used for hurricanes so we can get some sort of comparability.

Finally, column F shows what's known as time UTC, which means coordinated universal time, and it's usually recorded in a format like the one you see here.

This gives extra power to the information because not only is it geo-referenced, it also can become temporal data.

So how do we add this data about typhoon Rai to a webmap to visualise it and make more sense of it? The following video clip provides a step-by-step guide demonstrating how to do this.

We're going to map the data for one particular tropical storm, which is typhoon Rai, which happened in December, 2021 and had big impact on the Philippines.

Let's go to add, browse layers.

Normally what you would do for yourselves is go to ArcGIS Online.

I'm looking for this in my content, but this will be shared with you.

And I'm gonna add that layer now.

So the layer has started to appear over here, but it's time enabled and it thinks we want to time enable it right now, so I'm just going to switch the time enabling off and you'll see that the whole track of the typhoon does appear.

So I'm gonna zoom in on that region just now and we can see the Philippines is right there in the middle of our screen.

To improve the visualisation of the data points, I'm gonna change the base map to imagery hybrid/ and we can see them a little bit more clearly.

We'll improve that in a moment.

Next I'm gonna go back to the layers panel and click the three dots, which enable me to look at the properties of this layer.

In the properties panel, we can see symbology and we need to click edit layer style.

So the first step is to choose attributes and in ArcGIS Online, they're called fields as well.

So if we click field and select one of the attributes, and the one we're gonna choose is wind speed kilometres per hour.

So if we click that, we'll see what happens.

And what you see, if I just remove that layers panel for a moment, is each point along the track has become a proportional symbol, proportional to the wind speed at each of those locations during the lifecycle of the typhoon.

Now these symbols are a bit of a jumble, so we're going to pick a style, and in the next panel, style options, we're gonna classify the data.

We have to switch that on and we're gonna choose equal intervals, change that to equal intervals if it isn't, and we're gonna choose six classes because that's roughly corresponding with the Saffir Simpson scale, including numbers below one.

What we then need to do is, because we're in kilometres per hour, we're gonna round the numbers to 10, which makes the intervals and the legend more coherent.

We could leave the symbols as we are, but we're gonna see if we can change them.

So we click symbol style and it opens another panel, and in that next panel we click basic point and we'll see a selection of alternatives.

We can choose any of these and there are several to choose from.

Now, you can choose any of the symbols in these categories here or upload one.

So here's one that I uploaded earlier on.

It's quite easy to do.

So I found a hurricane symbol and jpeg or png, I dropped it into the box just here, and when you do that, click done and select it, it'll change all the symbols to that hurricane symbol.

Then we click done twice, there and there, and then we can save our work.

Very simple this time, we just click save and save because we've already named our map earlier.

What we might have noticed is the smaller symbols are very small, and we can improve that by going to style options and just making the smallest ones large enough to be visible without making 'em too big.

So we've gone for a size of 15 pixels, we'll leave the largest ones at 40, although we could change those as well.

Then we click done.

So now the data points have been visualised much more effectively.

And now we can use the points to make a track for the tropical storm.

So we go to add, create sketch layer, and this time we're going to create a line and we're gonna literally go from one point to another like this.

Doesn't matter if you don't get them all exactly right.

You can see I'm going through the whole course of the tropical storm through the Philippines, and we could draw a line clicking each time like this and it'll create a track, which if the points are switched off for any reason, we can still see where the track of the hurricane was.

So what we could do is then just change the colour to red and even add an arrow to it.

And you can see the direction of the hurricane tracking through south of China.

Now the track appears above the data points, but we can fix that by going to layers.

And there's a reposition tool just here, these little dots, and we literally just move that above there.

And what we can also do is rename that sketch and call it, "Rai track." And what we've done is we've placed the line, the track underneath the data points, which is gonna be much easier for us to deal with.

Now as you may recall, this data is temporal data, so we can use the time slider to animate it.

What we're gonna do is just click properties off and switch the time slider on, and we have time enabled data.

So what we can do is click the small three dots here at the end of the time slider, and it gives us some time slider options.

In the time display that appears on the left, we're going to ask it to show the data progressively.

That means we'll see all the dots rather than just a few of them.

We're gonna leave the dates as they are because it picks them up automatically.

We're gonna change the time interval to one day.

So we're going to see the data points revealed one day at a time.

Then we can visualise the time enabled data by pressing play or indeed the next or previous.

So let's press play and see what happens.

And sure enough, we can see the data points being revealed one group at a time, one day at a time throughout the lifecycle of Typhoon Rai, going right up to the South China Sea where the cooler waters meant that the hurricane dissipated because it ran out of energy.

As a final step, we're gonna configure the attribute data in the pop-up panels.

So to do this, we click the layers panel, and for the layer of data, we click options, then show properties.

In the panel on the other side, the lighter panel, click pop-ups just here on the right.

This opens the pop-up dialogue, but also a panel on the map so we can see the progress of any changes that we make.

So we're just going to make a few simple changes.

The title of the pop-up is currently this, so I'm going to just change that to, "Typhoon Rai data." Then in the fields list, I don't really need to see the latitude and longitude, so I'm gonna cross those out.

And the other thing we could do is maybe move one of the fields.

So for example, I could move wind speed kilometres per hour to the top, wind speed miles per hour to that point there.

And you can see it's changed here, which can help to improve the visualisation of the attributes in the pop-ups.

So if we close some of the panels, the map is now in a position to help us answer some questions.

For example, which cities, or indeed islands, were closest to Typhoon Rai's track? We can use pan and zoom to identify those.

How many days did Typhoon Rai have wind speeds above 240 kilometres per hour? That's roughly equivalent to Saffir Simpson scale of four or above.

We could use the pop-ups and the attribute data to do that.

And how could the visualisation be improved? Could we map a different attribute? Could we change the speed of the visualisation? And so on.

Soon you'll have the chance to map the data for Typhoon Rai yourself just as you saw in the demonstration.

But before we do that, let's just check and see if you picked up on a couple of key points from that demonstration.

The first question is, which of these is another term that ArcGIS Online uses for attributes? You may wish to pause the video here and restart it when you've selected your answer.

Well done if you chose B, fields, which is another word we use for attributes in ArcGIS Online.

Now for a second check.

Which one of the following icons do we use to access the pop-ups dialogue in ArcGIS Online? Once again, pause the video here and then restart it when you've selected your answer.

Well done if you chose A, the cog symbol, not to be confused with B, which is the symbol for toggling the time slider, or C, which we use for toggling the visibility of layers.

Now for the tasks which will help you to visualise the data about Typhoon Rai.

In order to do these tasks, you'll need to open ArcGIS Online using the Oak link provided, sign in and then click map to open Map Viewer.

There are three tasks.

Task one involves adding the Typhoon Rai data points.

Task two enables you to add a storm track and configure the temporal data to show the development of the typhoon during its lifecycle.

And task three has guidance to help you to configure attribute data in the pop-up panels and use your visualisations with three questions to follow up with some straightforward analysis.

So pause the video now to take some time to undertake task one, two, and three.

When you've finished press play to obtain some feedback, See you on the other side of the tasks.

Hopefully the tasks went well for you.

For task one, adding the data points and task two, adding the storm track and configuring the temporal data, hopefully your map looks something like this, with the time slider showing stages in the lifecycle of the storm.

For task three in which you were configuring the attribute data to appear in the pop-up panels, here's what they should look like when you click each data point in the lifecycle of Typhoon Rai.

Notice that the data point becomes highlighted when you click on it so you can check which point is being referred to.

There are also some short questions linked to task three.

For task 3a, you needed to look at your map to find the names of cities closest to Typhoon Rai's track.

Now this list isn't exhaustive, but you'd be doing well if you found these.

Surigao City, Cebu City, Bohol, San Carlos City, Bacolod City, Iloilo City, Puerto Princesa City.

There may be others.

For task 3b, you were asked how many days did Typhoon Rai have wind speeds above 240 kilometres per hour? Well, we can see from the data and the visualisation that Typhoon Rai had wind speeds above 240 kilometres per hour for five consecutive days from the 15th to the 19th of December inclusive.

Finally, for task 3c, you were asked to consider how might the GIS visualisation of Typhoon Rai be improved? You could have included ideas like these.

A different attribute could be visualised.

For example, we could have visualised the Saffir Simpson scale.

Time intervals could be shorter, such as six hours.

And the play rate could also be used to make the visualisation faster.

Well done, we've covered a wide range of GIS knowledge and skills, and my recommendation would be you return to these and practise them so that your GIS capabilities become fluent.

Let's summarise the learning that we've done in today's lesson with these key points.

First of all, ready-made tropical storm layers, that's layers made by someone other than ourselves, can be configured to visualise spatial patterns effectively.

For example, using filters to select data.

GIS pop-up data can be used to analyse tropical storms. Yes, we just click on the data points to see the data geo-referenced to that location.

Then we found out how geo-referenced data about a particular tropical storm, such as Typhoon Rai, can be mapped using GIS and then configured to show selected attributes.

And finally, a tropical storm track can be visualised using temporal data in a time-enabled GIS map, and that gives the visualisation much greater potential using spatio temporal data.

So we've covered a lot in this lesson.

Really good work.

I hope you found the knowledge and skills to do with GIS in the context of tropical storms useful and interesting and very much look forward to learning together with you in a further lesson.

All the best and bye for now.