Defining Coasts

I'm doctor Chris Spencer,

based at the University of the West of England in Bristol.

And when I'm working with students looking at

understanding the coast,

one of the first I ask is what is the coast. Perhaps seems a

really simple question.

And the answer that comes back is nearly always.

It's the border of the of of the land and the sea

or maybe the boundary between the land and the sea.

All true, all potentially

good definitions,

essentially what it says in the Oxford English dictionary.

But I think it's really important for us as geographers

to start think a little bit more broadly.

And I think one of the most important things is that we

need to start to see the coast as a zone rather than a line on the map.

And one of the real problems that we have and real

challenges that we have when it comes to managing the coast is

that for too long, We've treated the coast as a line on a map.

And we've treated one side of that line to be our

development, our hotels, our nuclear power stations, our homes, our

Transport links, and at the other side of that line is the

sea, is the waves, the tides, the storms, the beaches,

and so on. And that's all rather too simplistic.

So we need you to think start to think about the coast as a zone,

and we could think about that just with the simple breaking

of a wave that we have the swash that runs up the beach

and the backwash that comes back down the beach. So

already, we've extended our line and made it maybe made it

two, three meters wide.

And then we could think about the tides.

So the tides would change it from a line to maybe something

hundreds of meters from low tide to high tide.

And that sometimes we get storms and we get flooding further inland.

So that's extending the coast further inland.

How far out to sea do we consider to be the coast,

the sources of sediment, sources of storms,

So it's really important that we start to see the coast as

this more transitional zone and and get away from the idea of

it being, a line on a map.

Other important things about coasts,

we could see all global coast blinds as essentially having three roles.

All coastlines behave as a defense.

So they absorb and dissipate all of the energy that's coming

to term in the form of storms and waves and tides. And here

in the UK, we live in a very stormy

part of the world at the downwind end of one of the

world's ocean basins. So our coast is vital in terms of

protecting our development.

We can think of the coast as being a habitat

these variable conditions from extremes of low tide where

the land is covered by the sea nearly twenty four hours a day

through to the extreme inland end where it's maybe exposed

to the air for nearly or as a day, perhaps a little bit of

sea spray, salt spray. We have all sorts of habitats,

overwintering birds feeding their fish spawning there or a

whole range of different plants and animals that use the coast

as their home.

And then the coast is a really important resource.

We use it for tourism for extracting sediments for

building for citing our industry for transport links.

So the coast is really important. It's a it's a zone.

It's an area of a very intense activity.

And around about sixty percent of the world's population live

at or nearby the coast.

And for good reasons, historical reasons that it was

easier to travel using the sea than it was over land. So many

of our global cities and our coastal, certainly true in

Britain if we think of our way around from London, South

Hampton, Bristol, Cardiff,

Liverpool, Glasgow.

We could work our way right around the coast that our major

cities are. Many of them are coastal.

We live there because the climate is somewhat more mild.

We have relatively mild winters in the UK.

They're kept warm by the Atlantic Ocean relative to

places like Canada that are at the same latitude

and for trade and and all sorts of reasons,

the coast is a really good place to be.

But we need to have a very good understanding of the coast if

we're going to be able to manage it off into the future.

So we need to understand the processes the way the land

forms develop and the pressures that there are at the coast if

we're going to be able to manage these coastlines off

into the future in a period of change,

in a period where we know we're going to have sea level rise

and increasing problems, at the coast.

So a way that we can do that is to start to think of the coast

as a system. And it's not a system entirely separate for

everything else. It's linked to the biosphere.

It's linked to the carbon cycle, the water cycle.

It's linked to river systems.

But we can think of it as an open system

alongside all of these other systems that, there are, on the earth.

And by using a systems approach, we can start to see

the coast as a series of components and start to

understand the links between them. How beaches feed sand dunes perhaps.

And that coastal systems have a series of inputs in the form of energy,

maybe sediments coming in from rivers.

The outputs, sediments blowing further inland,

sediments leaving a particular coastal area.

We can think of them in terms of flows and transfers of

sediment and a whole series of feedback system negative and

positive feedback systems that

lead the coast to establishing some sort of equilibrium.