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Hard Engineering Techniques

 The table below shows a range of hard engineering techniques.

Technique Description Advantage Disadvantage Approxim

ate Cost

Groynes Groynes are

wooden barriers

constructed at

right angles to

the beach to

retain material.

Material is

trapped between

these groynes

and cannot betransported away

by longshore drift.

Groynes

encourage a wide

beach which

helps absorb

energy from

waves, reducing

the rate of cli

erosion.

Cheap, retain

wide sandy

beaches and do

not aect access

to the beach.

Beaches to the

south of the

defences are

starved of

beach material

due to their

aect on long

shore drift.

!""" each

#ea $alls #ea walls are

usually built along

the front of clis,

often

to protect

settlements. They

are often

recurved which

means waves arere%ected bac& on

themselves. This

can cause the

erosion of

material at the

base of the sea

wall.

'rovide e(cellent

defence where

wave energy is

high, reassures

the public and

long life span.

)(pensive, can

aect beach

access,

recurved sea

walls can

increase the

erosion of

beach material.

*"""+

"""-m

eventments Traditionally these

have been

wooden slattedbarriers

/ess beach

material is eroded

compared to asea wall. Cheaper

#hort life span

and unsuitable

where wave

0"""-m

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constructed

towards the rear

of beaches to

protect the base

of clis. )nergy

from waves is

dissipated by

them brea&ing

against the

reventments. 1n

recent times

concrete

reventments such

as accropodes

have been used in

places such as#carborough.

and less intrusive

than a sea wall.

energy is high.

oc& armour -

boulder

barriers

 These are often

large boulders

placed along the

base of a cli to

absorb energy

from waves.

Cheap and

e2cient

3nattractive,

dangerous

access to

beach, costs

increase when

roc& is

imported.

*"""-m

Gabions This is where

roc&s and

boulders are

encased in wired

mesh. They

absorb the energy

from waves.

Cheap and

e2cient.

#horter life

span than a sea

wall. 4isually

unattractive.

5""-m

6+shore

brea&water

 These are large

concrete bloc&s

and boulderslocated o shore

to change the

direction of waves

and reduce

longshore drift.

 They also help

absorb wave

energy.

Beaches retain

natural

appearance.

7i2cult to

maintain,

unattractive,does not

protect the

clis directly

and does not

stop beach

material from

being eroded.