Lesson video

Hello, my name is Mr. Conway.

I'm very pleased to have this opportunity to guide you through today's lesson and the emphasis is gonna be very much on GIS, otherwise known as Geographical Information Systems. So let's get started.

This lesson is part of the Fieldwork unit, and by the end of today's lesson, the intended outcome is that you're gonna be able to use 2D GIS to visualise and analyse physical geography fieldwork data.

You'll be learning to use GIS, which has quite wide applicability and some of the learning may be new to you, but I'll be here to support you along the way.

To help us achieve the outcome, we need to learn or remind ourselves about certain keywords and these are the keywords for today's lesson.

Georeferenced, attribute, bearing, and historical maps.

If we look at these in a little bit more detail, we see that georeferenced refers to any information which has been tied to a particular location.

We sometimes say this is geolocated and it uses an agreed system to do that such as latitude and longitude.

An attribute is any data value that's associated with a feature or variable measure in GIS, and sometimes the term field is used when referring to attributes.

A bearing is any angle measured clockwise from zero to 359 degrees, and it's often used to orientate attribute symbols in GIS to show direction.

And finally, historical maps refers to maps from any time in the past, which we can now compare with present day or recent maps, and we use those quite often as secondary data.

Field work is often conducted in physical landscapes such as river valleys.

2D GIS is a vital aspect of fieldwork because it can visualise and analyse river features and processes, including human impacts on the physical landscape.

As we'll see in this lesson, 2D GIS can use primary or secondary data or both.

For any data to be used in GIS, it's got to be georeferenced and in case you're not sure what that means, we'll be looking at that very soon.

But let's have a look at our fieldwork context first.

This is the beautiful Shropshire Hills, which were shaped by glaciers at one time, but since the Ice Age, river processes have dominated the landscape creating landforms such as these classic interlocking spurs.

This particular valley has been shaped by the River Ashbrooke, which has created the area now known as Carding Mill Valley.

But human activity has also had a very significant impact on the physical landscape.

There've been many centuries of changing economic activity, and in fact, a hill fort on a nearby hill called Caer Caradoc is thought to have been established around 3,000 years ago.

The most significant economic activities in more recent times fall into four sectors.

Primary activities such as agriculture, that includes hill farming, quarrying, and the water industry.

Secondary sector activities such as textile manufacturing were really important and in fact, the name of the valley takes from the mill where carding of wool took place, a process for disentangling, cleaning, and mixing wool fibres to be used in the textile industry.

Tertiary activities are important.

There's a strong tradition of leisure and tourism in the area, including spa facilities and more recently for all kinds of outdoor activities.

Quaternary activities take their place as well.

There's a wide range of research that takes place due to the fascinating local geology, the rivers, wildlife, and conservation work.

So consequently, there's an absolute wealth of geographical interest in an area such as this.

So fieldwork is required to investigate it.

Why do we need GIS fieldwork data about such areas? Well, one reason is that it's used to improve understanding of a river's behaviour, which informs decisions about how it might be managed and river management along the River Ashbrooke is absolutely nothing new.

It's taken place for hundreds of years.

There's been hard engineering such as weirs, dams, and river straightening, which we sometimes call channelization.

Let's just pick up on this crucial aspect of GIS called georeferencing.

It's the very precise location of a place using decimal degrees of latitude and longitude so that it can be used by GIS.

So we can see the very precise location of one of our fieldwork sites in Carding Mill Valley.

There are various ways to find this, but what we've used here is the location tool in ArcGIS Online and selected the option which gives us decimal degrees, it's abbreviated to DD, which GIS can then use very easily.

The value of this is that we can then use GIS to link any data collected at site one to that very precise location.

How accurate can this be? Well, using six decimal places, we can use a ruler to see that this can provide a precise location on the planet with a diameter as tiny as 111 millimetres or just over 11 centimetres.

Such precision becomes very useful when comparing places, particularly when they're close to each other.

So how can we georeference our primary data? Here we can see a GCSE student measuring river depth and width attributes so that they can calculate the cross-sectional area of river channel in square metres.

When measuring such attributes of a river channel, we need to also record the precise location of each site, and there are different options for doing that.

One way is to use an automated GPS-enabled device and it might have an app such as Survey 123, and that can record the decimal degrees of latitude and longitude alongside the observations being made.

Or another way, a more traditional way, is to mark the location on a conventional map and use GIS maybe later on to georeference the location.

As well as the georeferenced location, it's important to record other information which can be used by GIS.

For example, the time of day, the date and the day of the week should be recorded because results may be influenced by these attributes.

Also, it's often useful to record the compass bearing in degrees for data involving orientation such as the direction of river flow.

When we visualise georeferenced data, it makes it much more useful and powerful to enable us to address inquiry questions, to test hypotheses or compare places.

Here's an example of an inquiry question for a river.

How does the river change with distance downstream from the source? We can then link hypothesis to that inquiry question.

For example, we might hypothesise that an attribute such as velocity will increase with distance downstream from the source and obtain data to test that hypothesis.

We're going to use GIS with some real data for the River Ashbrooke and it was collected by small teams of students from eight sites in the upper course.

At each site they collected quantitative data and that data included measurable attributes of the river channel such as velocity, discharge, width, and depth.

Width and depth could then be used to calculate the cross-sectional area, which we call the CSA at each site.

As recommended earlier, they also recorded the compass bearing for the direction of the river and temporal data such as the time of the observations.

Furthermore, they collected qualitative data at each site including photographs and field sketches.

How does this attribute data need to be set out on a spreadsheet for GIS? Well, here's an example.

We have columns for georeferenced data and site numbers, the attributes of the river channel that we discussed earlier on.

This includes the calculation for the CSA, which is width times depth.

The bearing, showing the direction of flow at each site, and the time and data of the observations.

We don't have room to show it here but there could also be columns for other data such as URLs of photographs or charts that we've created.

Here's a video guide about how to do these things so that you can use 2D GIS primary data for physical fieldwork.

This guide is going to demonstrate how we can use 2D GIS to visualise primary fieldwork data as proportional orientated symbols.

Then how we can configure the pop-up data and configure the time or temporal data associated with those symbols.

So we're using a ready-made map with some ready-made layers and when you first open it in ArcGIS Online after you've signed in so that you can save it later, one of the things you might need to do to start off with is to switch off this button here, the time slider.

We'll use that later on and also click the cross to close the layers.

This is because the map opens by default with these open.

So if you just shut those down and we've got a clear start to what we're gonna do.

So we can see some points with orange dots and they are the sites that we use for students to collect their fieldwork data.

We've also got the river course which is shown, it's not complete, it's just showing the upper course of the River Ashbrooke.

So we open the river layers and we can see we've got River Ashbrooke data.

If I click the little eye symbol here for visibility, you'll see it disappearing and reappearing.

And we're gonna click Show Properties for that layer and the panel will open on the right.

Now the layer contains quite a lot of data collected under different attribute titles.

So we want to take one at a time.

So we're just gonna see how we can map one of them.

So we go to edit layer style and we're asked to choose attributes.

And what we want is to choose one of the fields which selects one of the attributes.

So if we click Field and then scroll down till we see velocity in metres per second, and we click that and add it and you'll see that the map will change.

So I'm just gonna tidy up the screen by shutting the layers panel so that we can see this a bit more clearly.

And what's happened is the data for velocity has been plotted and it's already showing it automatically as proportional symbols.

So let's see if we can find a symbol that's a bit more appropriate for this data.

We go to the panel again on the right and we choose pick a style and we go to the Counts and Amounts panel.

There are others, just choose the Counts and Amounts panel for style options and then you'll see symbol style with a pen.

Click the pen just once and it will open another sub-panel if you like.

If you click Basic point and then Basic shapes, it will open some more choices for us for different symbols.

Scroll down to where it says arrows and there's a whole selection of arrows we can choose from.

They've all got names over them if you float over them, but the one that I want you to select for now is this one called Arrow Cutout 2.

So if we click that, the symbols should change to that.

If that happens, and hopefully it has, we click Done.

But before we move on, we want to change the colour.

So, we're going to change the fill colour and if we click that just once, what we can do is select a different colour.

Now you can choose the colours by just going through the panel here until you find one you like.

We're not gonna suggest a hex code for one colour that seems to work quite well and it's this one here, 004ff, with the hashtag in front of it.

You can see it's changing to quite a bright blue.

So we're going to click Done when we've done that.

Then we're gonna close this sub-panel symbol style and scroll to something called Size range.

And what we can do is then change the size range but before we do that, just switch off this tick for adjust size automatically, and we're gonna change the lower size to 25 px and the upper one to 75 px.

So the symbol size is a little bit more appropriate now.

We haven't got such sort of dominance by the largest one and disappearance by the smallest one, we have a range.

And we're going to do one other little thing here, which is to scroll right down to the bottom of the panel on the right to something called rotation by attribute.

So if we click that dropdown menu just there and we're invited in this button to rotate the symbols based on attribute values.

Now one of the values in the data is the bearing, the student recorded the bearing using a compass of where they were in the flow of the river.

So we can show the direction of the flow.

So if we click this once, we'll see that doesn't happen until we change the field for that, that rotation field to bearing.

So we click Bearing and let's see what happens to the symbols.

You can see that they've all changed to show the direction of flow at that point in the river.

That's a much better visualisation of the data about velocity.

Then what we're going to do is go to the layers panel and our River Ashbrooke data is now showing velocity.

So we're gonna click the three dots for options and rename it as Velocity.

We could give it a longer name, but we're just gonna do that for now.

And then we click OK and if we click Legend, we can see the panel opens there and we've got a much clearer idea of what's going on.

So we then save our work and a good idea would be to slightly change the title, up to you.

I'm gonna Save As for the first time, and we're gonna call it Fieldwork.

Could be P1 or P2 or your initials.

So I'm going to put one after that to save that in a different title.

Our next step is to configure the pop-ups for these symbols.

So we go to the layers panel and we make sure we go to the newly named velocity layer.

Click the three dots for options, then Show Properties.

We see them on the right hand side.

This time we're going to click pop-ups, which is the symbol over here.

And when the panel opens, it offers a fields list and it has a progress panel over here on the middle of the map.

And by default, all the attributes are shown in this panel here.

We don't really want all of them.

So we click the three dots here to delete them and they will disappear.

And we're left with the title but we can change that to anything we want to.

So we can just change this title by typing something different.

We're gonna type River Ashbrooke, but notice I've put at the end something in curly bracket, which is the site number.

And that curly brackets means it's telling the GIS to pick up one of the attributes from the spreadsheet.

And in this case it's picking up the site number.

So you can see for every site number we have that showing.

And in a similar way we can add text by clicking Add content, and then Text.

And we can type a formula of words such as this.

So we're picking up the velocity attribute, but we put words on either side of it to make it make sense.

So you'll see that appearing in the pop-up now.

And we can add other things too, such as imagery or chart.

So if we click Add content once again and click Image, go to Enter URL, and this time we're gonna pick up something directly from the data and it's going to be the image URL.

So there's a URL for an image of a photograph about that site.

So if we click that, you can see that should appear in each pop-up.

So when we've done that, we can click Done and we can just check that each of the symbols is showing something different.

We can see the different symbols there.

Each of them now has a photograph.

Then we click Save and open and Save to save our work.

One last thing we can do here is to use that time data we talked about earlier.

So if we just shut the layers panel and the properties panel and we click the time slider, this little clock symbol on the right, it provides a time slider in the bottom of the screen so we can use that to toggle the time slider on and off.

The reason for that is because it's only showing something that's in this time slot here, but we can change that by going to time slider options.

And when that opens up, we can change the default from show recurrent interval, which it's doing there, to show features progressively.

And when we do that, we can then use the play button.

I'm just gonna shut the time slider options there for a moment so you can see it a little bit better.

And what we can do is we can see how the points will appear sequentially because I've pressed play and it's just loading them according to the time when the data was collected.

Soon you'll have the opportunity to use 2D GIS primary data yourself.

But let's just check up on a few points from the video guide.

In GIS, what type of bearing data is needed for direction or orientation to be visualised by rotating a symbol such as an arrow? If you want to have some time to think about that, pause the video here for a few moments.

Well done if you selected A, the number of degrees clockwise, which can be any number between zero and 359 degrees.

Now for a second check.

Which two data attributes are essential to enable data to be georeferenced to a precise location? Once again, pause the video here if you wish.

Restart it when you've selected your answer.

So, the two correct choices here are decimal degrees of latitude, that's B, and decimal degrees of longitude, that's D.

Now for the task which are gonna help you to use 2D GIS primary data yourself.

For these tasks, you're going to need to open the link provided, which takes you to a ready-made map called Fieldwork letter P, and that's P for physical.

In task one, you're going to visualise primary data as proportional orientated symbols.

In task 2a, you'll be configuring pop-ups for the river ash Brooks primary data, and in task 2b, you'll configure time.

That's what we call temporal data for that same batch of data.

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

Hopefully the task went well for you.

For task one, your webmap visualising primary data as proportional orientated symbols should look something like this.

For task 2a, your configured pop-ups for the River Ashbrooke data may look similar to this.

And for task 2b, your time enabled-data may look like this, including in this GIF we can see the time slider options being opened to show the features progressively.

And we can see the sequence of data downstream as it was collected.

If your outcomes are very different to those, take a look back at the video demonstration to see if there's any particular steps you may have missed out.

Our second learning cycle will focus on how we might use 2D GIS secondary data for physical fieldwork.

How can secondary GIS data support our fieldwork inquiry? Well, there are various ways.

For example, we might use georeferenced historical maps or we might use current georeferenced flood risk maps, or sketch maps which have been georeferenced as media layers, and then compare such data with our primary data.

Let's take a quick look at how these might work for us.

As a source for historical maps, the National Library of Scotland Maps Department, which we may abbreviate to NLS Maps, is second to none, not least because they've georeferenced many thousands of historical maps.

You can see an example here of just one of the historical map layers, in this case, for Shropshire.

It shows the area for our fieldwork data around the settlement of Church Stretton alongside the River Ashbrooke in the Carding Mill Valley.

It's a superbly crafted, highly detailed ordnance survey map from some time in the mid 19th century.

What's more to make comparison with our primary data easily comparable with this secondary source, NLS maps make it possible to bring such historical maps into ArcGIS Online.

It's what's called an overlay and you'll be able to use that later.

Another very useful type of secondary source for us to use is GIS flood risk maps, which are produced by government departments such as the Environment Agency.

Part of their role is to provide free access to their visualisations of what are called Risk of Flooding from Surface Water.

This is a bit of a mouthful, so it's called RoFSW for short.

These layers can be loaded into ArcGIS Online and we can then make links with our primary data.

What you can see here is that we've laid that data over the imagery hybrid basemap.

You could change the basemap if you wanted to.

So this one currently shows aerial imagery with added labels of places including street names.

Each level of risk is expressed as a probability and color-coded like this.

3.

3% probability or a one in 30-year flood is shown in blue.

So that's the most likely type of flood.

Less likely is a 1% probability.

That's a one in a hundred year flood and that's shown in yellow.

And the rarest flood extent, which is 0.

1% probability or one in a thousand year flood is shown in green.

You'll have a chance to work with these soon in the tasks.

Another recently available way to use secondary data is the excellent media layers tool in ArcGIS Online, which enables direct georeferencing of certain types of spatial data such as historical maps or in this case, a sketch map of the Carding Mill Valley.

Here's a glimpse of how the media layers tool works to carry out the georeferencing.

Here's a second video clip providing a step-by-step guide showing how to use a couple of types of secondary GIS data for physical fieldwork.

This guide is going to show how we can use our ready-made map to look at secondary data to support our investigation alongside our primary data.

And in layers, if we look down the list, we can see there's one called OS Six Inch 1830s to 1880s.

So if we click the visibility button to make that visible, we see this layer has appeared.

Just gonna close the layers panel for a moment and the time slider.

And you can see quite an old map has appeared, a historical map in black and white.

Now this ordnance survey map is from probably the middle of the 19th century and it truly is an amazing piece of work as with many of the old maps that are stored now on the National Library of Scotland Maps website.

And what you can do is look at those and sometimes you can use them as overlays in ArcGIS Online, and that's what we've done here.

It's been used as a tile overlay.

So to use this layer in association with our primary data, if we click the layers panel and then click the properties for the OS map and then just click the layers panel so we can see a little bit better.

And we see there's transparency slider, which we can slide like this to compare the modern imagery with the older map that we've overlaid, and we can then compare it with our sites.

So we'll do that in a moment but first of all, let's have a look at a place along the river called Ashbrook, very similar to the name of the river except there's an E missing.

So we search for that and it will take us to Ashbrook.

We can see it just there, and we can inspect the issue of what's happening with the river around that, using the modern imagery and comparing it with the historical map.

So if we use the transparency slider, we can see quite a significant change since the 19th century.

Just look at how many houses have been built next to the river and near the river.

So you can explore that.

And if we look upstream, let's have a look particularly at Site 6, which is this one.

We'll just click it to check that is Site 6.

Yes it is.

So we can see a photograph of it there.

And if we look at this in a little bit of detail and use the transparency slider, what we notice is that there have been a few changes.

So if we zoom in, we can see how that's happened and what can help us with this, if we actually change the basemap to OpenStreetMap, then we're going to use the transparency slider and we can spot the differences a little bit more easily.

What you may see in particular is that two of the old reservoirs, little reservoirs, one here and one here, are no longer there.

There's one that remains.

And if we pan out just a little bit more, we might see another difference further upstream, we can see there is actually a new reservoir which wasn't there in the 19th century.

So we can make comparisons with that and consider what the impact might have been on the hydrology of the River Ashbrooke.

A little further downstream we can see some other interesting comparisons.

So we're just gonna change the basemap back to imagery for this one.

So if we move the map down towards Site 7, and we'll zoom in to look at this in a little bit more detail, we can see some buildings here.

If we go back in time, we see that this was actually the Aerated Water Works Carding Mill itself and Quarries.

Are they still there? Almost certainly not, although the buildings may be.

And what we can do is check the function of those buildings by going back to the OpenStreetMap to see what's going on there and that might give us some clues.

So if we look at the transparency like this, we can see that is now a National Trust Gift Shop.

There's a cafe there, there's some toilets.

I don't know whether these are houses or not, but they certainly have changed their function over the years.

Another set of secondary data that's built into the map is a much more recent, quite modern layer, which is the Risk of Flooding from Surface Water Extents.

And this is a GIS layer prepared by the Environment Agency, which is a government agency, and they're responsible for letting people know about flood risks around the country.

So if we click that to on with the visibility button and to make it a little bit easier to see, we're just going to switch off the historical layer, but put back the basemap for imagery.

So when we do that, if I'm gonna put Imagery Hybrid, because that shows road names, I'm just gonna switch off properties for the moment.

We can have a look at the other sites gonna switch off basemap as well, so we get a better view.

We can see the sites and explore the flood risk map around those sites.

So we can do that quite easily but I'm just gonna suggest you look at a place in Church Stretton, not very far away.

We're gonna search for it here by looking for Swain's Meadow in Church Stretton.

And it will take us straight there because then we can look at the flood risk maps in a little bit more detail.

So here's Swain's Meadow and some other roads nearby.

If we look at the layer for the flood risk, we can actually see there's an arrow, which means it's actually three layers in one.

So if we click that, we can see these layers.

We just scroll the layers panel there a little bit, and we can actually remove the layers one by one like this or put them back.

So if we just put the layer which shows the 3.

3% annual chance of flooding, then we can add the 1% annual chance of flooding, and then the 0.

1%, the least likely form of flooding.

So what we've got there is a pattern where we can actually analyse the flood risk for the area.

And it's worth considering why there seems to be a greater area of flood risk here than there would've been upstream.

So one reason could be that the valley upstream is in the upper course, the valley, the floodplain isn't very wide there.

The other thing is there are no trees in that area.

So, the water is getting into the river very quickly there, which actually could be contributing to the greater flood risk downstream in Church Stretton.

By that time we're of course in the middle course of the river.

Soon you'll have the opportunity to use 2D GIS secondary data for physical fieldwork.

But let's just check up on some of the points from the video demonstration.

Which GIS tool is very useful when making links between primary data and secondary data, such as historical maps? You may wish to pause the video here and restart it when you've selected your answer.

The correct choice is D, transparency slider, where you can change a layer's visibility to enable easier comparisons.

Now for a second check.

Is it true or false to say that the only basemap which shows street names is OpenStreetMap? You may wish to pause the video here and restart it when you've selected your answer.

The correct answer here is false.

Pause the video again to consider why this statement is false.

Okay, the reason that the statement is false is quite simple.

It's because many other basemaps do show street names, sometimes including the name hybrid, such as Imagery Hybrid to tell you that they include that data.

Now for the task which will help you to use 2D GIS secondary data for physical fieldwork.

As for the tasks in learning cycle one, you'll need to access the same ready-made webmap called Fieldwork with the letter P after it, short for physical.

The link is here in case you don't have it open already.

There are four short link parts to task one, which are gonna help you with linking secondary historical maps with primary data.

In task two, which has two parts, you're going to link secondary flood risk data with primary data.

And for task three, you need to consider a more general question.

How effectively can GIS present our data and inform our conclusions? So pause the video now to take some time to undertake the tasks.

When you're ready, press play to obtain some detailed feedback.

For task 1a, where you are linking secondary data in the form of historical maps with primary data, your webmap should have looked something like this.

Then for task 1b, some valid about land use changes in and around Ashbrook could be that there's been a lot of building.

We see much housing now built near the river on a floodplain.

A consequence of all these buildings and their roads and other infrastructure would be a major increase in impermeable surfaces in the area.

As a result, we might expect that lag times to the River Ashbrooke will be much reduced, increasing the likelihood of flooding.

For 1c, comments about river management changes around Site 6 might include things such as the fact that hard engineering has been used and altered such as weirs or dams. We see that the New Pool, small reservoir has disappeared, and a new reservoir has appeared to the southwest along New Pool Hollow.

It follows that such changes might have an impact on lag times for flood events.

For 1d, we can see several interesting land use changes around Site 7.

For example, there's clearly been a big change from primary and secondary sector activities to tertiary and quaternary sector activities.

In the primary sector, activities of declined.

Quarries now seem to be abandoned and covered in vegetation.

In the secondary sector, the former Aerated Water Works and Carding Mill buildings have been repurposed.

There's evidence of a transition from historical secondary sector activities here to tertiary/quaternary sector activities.

For example, the National Trust now operates premises and a car park, and that's going to be able to support industries such as leisure, tourism, and quaternary research.

For task 2a, linking secondary flood risk data with primary data, your visualisation should have looked something like this.

For task 2b in answer to the question, why do flood risks at Swain's Meadow exceed risk at fieldwork sites? The following points could be made.

Flood risks at Swain's Meadow are more extensive than the fieldwork sites because it's in the middle course where the valley is flatter and wider.

The upper course has fewer trees and that reduces lag times and increases flood risk downstream.

For task three, how effectively can GIS present our data and inform our conclusions, you may have expressed opinions similar to Alex who found that "2D visualisations of georeferenced primary data show velocity increases with distance downstream from the source.

The bearings data is a great way to visualise the river flow." Aisha commented that, "Configuring pop-ups is an excellent way to visualise each site and its data.

The time slider shows the sequence of our data collection and emphasises attributes change downstream." Good point.

Sofia said that, "Layers of secondary data such as flood risk or historical maps help us to make important links between data sets, changes in river management, identify anomalies and suggest explanations." If there are any particular issues with the work that you did, take another look back at the video presentation to check all the steps.

Excellent work.

We've developed 2D GIS knowledge and skills that will be really useful for your physical geography fieldwork.

It's this kind of deliberate practise that can help make our use of GIS much more fluent.

Let's just summarise the learning in this lesson.

2D GIS can be used in all sorts of ways.

First of all, to visualise and configure primary georeferenced data attributes from our physical geography fieldwork.

It can use attributes including bearing data to create proportional orientated symbols that support the visualisations.

Then it can also be time-enabled using temporal data attributes to enhance the visualisations.

And the use of visualisations as secondary data such as secondary maps can be used to support fieldwork inquiry by making links with that data.

So we've found out how to use a useful range of powerful GIS tools in this lesson.

A really good way to follow this up is to use similar approaches with your own physical fieldwork locations.

I really hope that you found the learning interesting and useful and look forward to further learning with you in the future.

So, all the best and bye for now.