IMPACTS OF MARINE ENERGY ON COASTAL SEDIMENTATION

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21 Φεβ 2014 (πριν από 3 χρόνια και 5 μήνες)

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IMPACTS OF MARINE ENERGY
ON COASTAL SEDIMENTATION
DAVIDPRANDLE
DAVID

PRANDLE
A)MARINEENERGY

PRACTICALITIES?
A)

MARINE

ENERGY

PRACTICALITIES?
B) TIDAL POWER
C) COASTAL SEDIMENTS
D) GRAND CHALLENGES
MARINE ENERGY

PRACTICALITIES ?


PARAMETER

THEORY

LA

KOREA

FUNDY

BRISTOL

RANCECHANNEL

SURFACE
AREA

22

56

86

420

Km
2

TIDAL A
AMPLITUDE
4.25 4.0 5.0 4.0 m

EMAX=
4
ρg
A
2
S/P

350

360

1900

5900

MW
ρg

Actual
Output

27

16

17

20

19

%

RatedHead
h

12

13

14

13

22

h/A
Rated

Head
,
h

1
.
2
1
.
3
1
.
4
1
.
3
2
.
2
h/A

Rated Flow, q


0.4

0.5

0.2

0.4

1.9

q/Q
ONLY WITH A CARBON TAX/SUBSIDY


PARAMETER

THEORY

LA

KOREA

FUNDY

BRISTOL

RANCECHANNEL

SURFACE
AREA

22

56

86

420

Km
2

TIDAL A
AMPLITUDE
4.25 4.0 5.0 4.0 m

EMAX=
4
ρg
A
2
S/P

350

360

1900

5900

MW
ρg

Actual
Output

27

16

17

20

19

%

RatedHead
h

12

13

14

13

22

h/A
Rated

Head
,
h

1
.
2
1
.
3
1
.
4
1
.
3
2
.
2
h/A

Rated Flow, q


0.4

0.5

0.2

0.4

1.9

q/Q
LIKELYSCENARIO?
LIKELY

SCENARIO

?
10
20year
'
window
'
forbitter
'
proof
'
ofGCC
10
-
20

year

window

for

bitter

proof

of

GCC
Renewable Ener
gy
Research Re
q
uirements:
gyq
Assess scale & nature of availability
Engineering designs for extraction
Assess associated environmental impacts*
*difftitftGCCit
*diff
eren
ti
a
t
e
f
rom concurren
t

GCC

i
mpac
t
s
B)TIDALPOWER

BARRIERCHARACTERISTICS
B)

TIDAL

POWER

BARRIER

CHARACTERISTICS
Ntild27%f'i'(
)

N
e
t
energy y
i
e
ld
~
27%
o
f

'
max
i
mum
'

(
one-way
)
•~ 37% ( two-way
•Sea levels in impounded basin ~ msl to HW
•Flushin
g
rate reduced ~ 50%
g
•10 year construction period

Noenergyproductionuntilcompletion

No

energy

production

until

completion
Tidalenergy
Tidal

energy
Tidal stream
devices
Marine current
turbines e.g. Seaflow
(left)
Stingray (below)
La Rance tidal barrage
TappingtheTidalPowerPotentialoftheEasternIrishSea
Cromarty Firth
Loch Broom
Tapping

the

Tidal

Power

Potential

of

the

Eastern

Irish

Sea
?
Tidalbarrageor
Loch Etive
R()
Lth()
Cit(MW)
Ott(GWh)
7.46m
?
11 hours
Solway
Tidal

barrage

or

tidal fence
Solway Firth
Morecambe bay
Mersey
Wash
Humber
R
ange
(
m
)
L
eng
th

(
m
)
C
apac
it
y
(MW)
O
u
t
pu
t

(GWh)
Severn7200001500022000
Morecambe6.31660040005400
Solway5.530000558010050
Tidal stream
Relativetimeof
Dee
Dovey
Milford Haven
Severn
Langstone Harbour
Thames
Hamford water
Dee5.9595008001250
Humber4.1830012002010
Wash4.451960027604690
Thames4.2900011201370
Irish
Morecambe
Relative

time

of

tidal high water
level
Direction
oftidal
Padstow
Langstone3.135502453
Padstowe4.755502855
Hamford332002038
L. Etive1.953502855
Irish

Sea
?
Ribble
Direction
of

tidal

propagation
Tidll
Cromarty2.75135047100
Dovey2.913002045
L. Broom3.155002942
MilfordHaven
4.5
1150
96
180
Mersey
8.5m
5
.
5
m
10 hours
?
Tid
a
l

l
agoons
Spring tidal range
Pr
e
vi
ous

U
K
ba
rr
age

s
t
ud
i
es
Milford

Haven
4.5
1150
96
180
Mersey6.4517506201320
Mersey
Dee
55
eousUbaagesudes
OPERATIONAL, UNDER CONSTRUCTION, DESIGNED BARRIER SCHEMES


PARAMETER

THEORY

LA
RANCE

KOREA

FUNDY

BRISTOL
CHANNEL

RANCE
CHANNEL

SURFACE
AREA

22

56

86

420

Km
2

TIDAL A
AMPLITUDE
4.25 4.0 5.0 4.0 m

EMAX

350

360

1900

5900

MW
EMAX
=
4ρgA
2
S/P
350
360
1900
5900
MW

Actual

27

16

17

20

19

%
Output

Rated Head, h


1.2

1.3

1.4

1.3

2.2

h/A
Rated Flow, q

0.4 0.5 0.2 0.4 1.9 q/Q
C)COASTALSEDIMENTATION
C)

COASTAL

SEDIMENTATION
FORCING
(tides,waves,storms)
↕↕
SEDIMENT ↔MORPHOLOGICAL
TRANSPORTEVOLUTION
TRANSPORT

EVOLUTION
all 3 closel
y
inte
r
-de
p
endent at the coast
y
p
Sediment transport –conservation eqn. with problems
NEAR
FIELDlocalisedscour/sedimentation
NEAR
-
FIELD

localised

scour/sedimentation
FAR-FIELD exchan
g
e of sediments on scales of :
g
tides
storms
seasons
seasons
climate events
glacialcycles
glacial

cycles
IMPACTSOFMARINEENERGYONSEDIMENTS
IMPACTS

OF

MARINE

ENERGY

ON

SEDIMENTS
Wind 'Mills'

local/small effect on wave climate
Tidal Barriers -'settling pond'
lar
g
e-scale shift of tidal
p
atterns
g
p
TidalStreams
interruptionofsedimentpathways
Tidal

Streams


interruption

of

sediment

pathways
Wave -potential changes in magnitude and
direction of longshore drift
Depth
Breadth
100000
Breadth
10000

100
1000
istance
(m)
10
D
1
16111621263136414651566166717681869196
FutureCoast estuaries number


Challenges for coastal sedimentation
IMPROVE DESCRIPTIONS OF:
1)SINKS&SOURCES
1)

SINKS

&

SOURCES

coast/estuary
2)EROSION & DEPOSITION
cohesives/mixed
3) FORMATION OF MESO-SCALE MORPHOLOGY
dunes/saltmarsh/channels/banks
4)EFFECTS OF 'INTERVENTIONS'
trainingwalls/dredging/railways/
offshoreenergy
training

walls/dredging/railways/
offshore

energy
GRAND CHALLENGES
COASTAL SEDIMENTATION
sensor
instrument development
ltf
p
l
a
tf
orm
flume experiments
modelling
modelling

coastal observatory
forecasting morphology
seasonal/post
-
event/long
-
term
seasonal/post
-
event/long
-
term

10
8
u
tflo
w
8
n
t inflo
w
/o
u
o
nnes)
w
s
= 0.0005 ms
−1
6
i
ve sedi
m
e
n
(million t
o
inflow
s
outflow
4
0
2
C
u
m
ulat
i
w
s
= 0.005 ms

1
inflow
outflow
2468141012161820222426280
303234363840424446485052545658
0

Semi-diurnal tidal cycles
NEAP
SPRING
NEAP
NEAP
SPRING
NEAP






High resolution Liverpool Bay/Dee coupled model
EA LIDAR/sonar survey, 2003, Dee Experiment
Model grid:
1/400degree
1/400

degree

longitude by 1/600
degree latitude
~200m resolution
Repeated1
-
month
267*187 grid points
Repeated

1
month

process studies
including observations
of waves, currents,
turbulence,
suspended sediment
and bottom profile
measurementsare
measurements

are

being made
PhD project on
morphodynamic
evolution
Geolo
gy
Tides
Surges
gy
morphology
Surges
Waves
Sedsupply
Sed

supply
Biol/chem
events
coastal
p
rotection
events
p
habitat conservation
Itf
turbulence
erosion/deposition
bd&tlft
I
mpac
t
s o
f

GCC
b
e
d

&
coas
t
a
l

f
ea
t
ures
‘interventions'