Hello, my name is Chloe, and I'm a geography field studies tutor.

This lesson is called "Fieldwork: Planning a River Inquiry and Collecting Data," and it forms part of the rivers, how the rivers shape the land unit of work.

In this lesson, we're going to be thinking about how we might plan a piece of river fieldwork.

We're gonna be taking some of the theory that you've already learned about, and then applying it to the real world to see if the real world matches the theory.

Let's get started.

By the end of this lesson, you will have collected some characteristics data about rivers as part of a fieldwork inquiry.

First of all, there's some key terms for us to review.

Let's start with Bradshaw model.

This is a theory that describes how the physical characteristics of a typical river change from source to mouth.

Bedload is geological material that is eroded, transported, and deposited by rivers such as stones, boulders, and sand.

The flow or the velocity, is the speed at which the water passes along a channel.

There are two parts to this lesson.

We're first going to be thinking about how we might plan a river inquiry, and then we're going to be looking at how we might actually go out and collect some data.

But let's start with that first idea about planning our fieldwork.

Geographers often use inquiries when they carry out fieldwork.

Let's look at some of the elements that make up a fieldwork inquiry.

First of all, we need to think about what actually needs to be investigated.

We formulate an inquiry question, and we'll also, of course, try to answer it.

We're gonna answer it by following a set inquiry structure, and part of that is about making predictions about the outcome of the inquiry.

A geographical fieldwork inquiry follows a set structure.

Let's have a look at that now.

So we start off with the inquiry question.

This is a question about the place that you are interested in.

Then there's a data collection stage.

This is where we measure and record data that will help you answer that inquiry question.

Following that is data presentation.

We present our data using maps, graphs, and charts.

In the data analysis section, we look for patterns in the data and we think about what the data is actually trying to tell us.

After our data analysis, we then make a conclusion.

We try to answer our inquiry question based on the data that we have collected.

And then finally, we evaluate.

We think about how we carried out our inquiry, and what we would change to improve the accuracy of our conclusions and our results.

So let's check our understanding of the inquiry process.

In what stage of a geographical fieldwork inquiry would a geographer try to find patterns in the data? Is it the data presentation, the data analysis, the conclusion, or the evaluation? Pause the video and have a think about that cycle that we just saw, and then come back to me with an answer.

Okay, let's see what you got.

Well done if you recognise that it is data analysis.

So let's start with the first part of our inquiry cycle, and that is actually formulating an inquiry question.

In this fieldwork inquiry, which is all about rivers, our title question is gonna be, "Does our local river behave like a theoretical river?" The data required to answer this question is the channel width, the channel depth, the flow velocity, and the bedload size.

Geographers use the Bradshaw model to predict what a river will be like in its different courses.

You can see an example of a diagram that represents the Bradshaw model here.

Theoretically, channel depth increases as one goes downstream.

You can see at the top of the diagram there, we've got upstream on the left-hand side and downstream on the right.

And you can see how the different characteristics change as one moves from upstream to downstream, as one goes from source to mouth.

You can see that the channel depth, which is now coloured pink, goes from very small to very large.

So yes, the channel depth should increase as we go downstream and closer to the mouth of the river.

Flow velocity also increases downstream.

Therefore, we can actually say that these two variables are relationally linked.

As channel depth increases, it would make sense that flow velocity also increases.

Bedload size decreases as one moves downstream.

You can now see the green triangle gets smaller as one goes downstream.

This means that bedload size and channel depth are also relationally linked.

This does not necessarily mean that one of these variables causes the other, however.

A hypothesis is a statement that can be tested.

Geographers use hypotheses to help them answer their inquiry question and to focus their ideas.

Alex and Sam have made some hypotheses.

Let's have a look at those now.

So Alex says, "I hypothesise that as the depth of the river channel increases, the flow velocity of the river will also increase." He's taking that directly from Bradshaw model.

Sam says, "I hypothesise, as the depth of the river channel increases, the size of the bedload will decrease." Sam again has taken that directly from Bradshaw.

So both of our students here are thinking theoretically about how a river should behave.

Let's check our understanding of the Bradshaw model.

According to the Bradshaw model, which of these statements is true? Is it A, the bedload size increases with distance from the river source, B, channel width decreases as channel depth increases, or C, flow velocity increases as the gradient decreases? Pause the video here and have a really close look at the Bradshaw model diagram that you can see there to see which of those statements is true.

Right, let's take a look at your answer.

Well done if you got that it is C.

Yes, flow velocity increases as the gradient decreases.

You can see that as the flow velocity triangle gets larger going downstream, the gradient size gets smaller.

Now, here's your first practise task for this lesson.

Examine a map of your local river.

Position an arrow next to the river channel to show the direction of flow.

Then your second task, label your map with the following phrases, theoretical area of greatest channel depth, so where on the map would you expect the channel to have the greatest depth, the theoretical area of the greatest flow velocity, where would you expect the river to be the fastest, and the theoretical area of the largest bedload size.

So all of that information can be placed onto a map.

Pause the video, have a go, and then come back to me.

Let's now take a look at your answer.

Here's a river that is close to me.

You first of all need to put on the direction of the flow.

So an arrow placed next to the river channel to show where the river is flowing from and to.

Then we have the second task where you had to label your map.

Here's what your answer may look like.

The area which theoretically would have the greatest channel depth should be the area of your map that is closest to the mouth of the river, so the area downstream.

And that will also be the area that will have the greatest flow velocity.

The largest bedload size, however, will be the part of your map that shows the river area that is closest to the source.

Hope you got those right.

Now let's move on to the second part of our lesson where we're thinking about collecting data in a river environment.

So here we are in the second stage of our inquiry cycle.

Data collection.

Channel width is measured by stretching a tape measure taut across the channel.

Depth measurements are taken at equal intervals across the channel using a metre stick.

You can see somebody doing that in the picture here.

You measure from the river bed to the tape measure line.

10 depth measurements should be recorded.

Your final reading should be zero centimetres, as it will be on the bank.

In other words, there's no depth there because you've actually reached the bank side.

At six of the depth measurements across the river channel, a piece of bedload should be selected.

So you're actually going to pick out a piece of bedload from the base of the river.

This could be the piece of bedload that the end of the metre stick rests on at each depth reading.

Each piece of bedload is measured along its longest length, and this distance is recorded.

To measure the river flow velocity, geographers record how long it takes for a float to travel a set distance on the river surface.

Flow velocity is then calculated by distance divided by time, to give a value in metres per second.

Floats should be easy to see.

If they were to get lost, it's important that they would not cause harm to the local ecology.

Small oranges or dog biscuits make excellent floats.

If they do get lost, they are relatively organic and so will break down naturally in the environment.

Let's take a look now at how you might measure flow velocity.

First of all, you measure out a 5 metre section of the river and place a marker such as a ranging pole, which you can see in the photograph here, at either end of the section in the middle of the flow.

You then place the float at the foot of the marker that is upstream.

Making sure one does not stand in a way that impedes the flow, release the float at the same time as starting a timer.

Stop the timer when the float reaches the second marker.

Collect the float and record the time taken.

Then repeat this twice more.

Let's check our understanding about flow velocity.

Why do geographers use oranges or dog biscuits to measure flow velocity? Is it because they're easy to see in the water? Is it because they have little environmental impact if they get lost? Is it 'cause they're cheap to buy? Or is it 'cause they're best at floating on moving water? Pause the video here and have a think about what we've just talked about, and then come back to me with the right answer.

Well, it's certainly true that they are relatively easy to see in the water, and they are definitely kinda cheap to buy, but the real reason is that they cause little environmental damage if they were to get lost.

A data collection sheet is used to record the data.

Here's an example of one here.

Three flow velocity readings are recorded, and the average velocity can be calculated.

You can see here it's actually being measured in seconds, and then the actual velocity can be calculated at a later point.

10 channel depth readings are recorded, and again, the average depth can be calculated.

These are measured in centimetres.

Six pieces of bedload are sampled from the centre of the channel.

Their average size can be calculated too.

These are measured in millimetres.

Aisha is thinking about where to carry out the data collection.

She wants to visit six sites along this stretch of the river.

She calculates that this stretch of the river is 1.

5 kilometres long.

She did that by using the scale that's on the map there.

Therefore, the sites should be every 250 metres or thereabouts.

She would also have to take into account where it is safe for her to get in and out of the river.

This means the sites have been systematically sampled.

There is a system that she has used in order to work out where exactly to do all of those measurements.

As well as collecting quantitative or numerical river data, geographers also draw field sketches.

Here's an example of one here.

You can see there is a small meander bend in this river and how it's then represented by the sketch.

A field sketch is a simple representation of the geographical features at the field site.

Though it is called a sketch, it is drawn with clean lines.

It is definitely the case that you don't have to be an artist in order to do a field sketch.

A field sketch has a frame.

It has a border around its outside.

It will have a title, and this will always include the view direction, so the direction that the sketcher is facing as they are completing the sketch.

It will have annotations to explain what the sketch shows.

It will also focus only on the most important geographical features.

If there are extra details in there, maybe the geographer doesn't actually have to include those unless they are important for the message that the field sketch is trying to make.

Let's check our understanding there.

Field sketches are artistic impressions of a geographical scene.

Is that true or false? Pause the video here, and then have a think and come back to me.

Let's check your answer now.

Well done if you recognised it's false.

But now tell me why that is a false statement.

Yes, it's certainly true that field sketches are about clearly representing the geographical features of a place.

They are not about the artistic skills of the geographer.

The nice thing about including annotations is that if you don't think your drawing really shows what you want it to, your annotations can add in those extra details.

Here's our practise task for this section of the lesson.

First of all, look at a map of your local river and the area that you will be visiting.

Choose your field sites along the river and clearly label these.

Then carry out your river survey at each site.

You're going to measure channel width, channel depth, flow velocity, and bedload size.

You're going to need to use one data collection sheet for each site.

Then for one of your sites, draw a field sketch and use at least two annotations.

Now, naturally you're going to want to pause the video here so you can get outside and have a go at these tasks.

Then come back to me and I'll show you some of the ideas that I have.

So first of all, you're asked to look at your map of your river and actually choose your field sites.

So your answer might look something like this, where you've got clearly where the river is and then you've got your sites marked on them.

Then you're going to want to actually go out and collect the data.

Here's some example of what one of your data collection sheets might look like.

You've got the site name or number in there, and then you've got the data according to the various calculations and measurements that you took.

Then for one of the field sites, I asked you to do a field sketch and I'd like at least two annotations.

So here's something your answer may look like.

Make sure it's got a title and a border, first of all, and make sure in your title that you've got that idea of which direction the sketcher was facing.

The annotations need to be relatively detailed.

They should include information which you wouldn't necessarily see directly from the sketch itself.

So on the left-hand side of the sketch here, it's talking about a steep river cliff.

Now, yes, we probably see that in the sketch, but what we might not understand quite so clearly is that that has been caused by erosion.

Then on the right-hand side of the sketch, the sketcher here has noted the undercutting has caused some trees to be uprooted and start to fall into the river.

So it's taking that idea of erosion and undercutting of the bank, and it's showing evidence of the impact that that has had.

Let's summarise our learning now.

A river channel survey helps geographers to see if and how a local river might behave like the theoretical river seen in the Bradshaw model.

A field sketch is a data collection tool that geographers use to understand more about their field site.

Well done on carrying out the first stage of your river field work inquiry.

There's nothing quite like going to a river that you've already learned about in lessons theoretically, and then seeing if it actually has the same processes and characteristics taking place there.

It's really memorable part of geography.

I hope you enjoyed your time at the river.