La variabilitat climàtica i

la costa catalana

A. Sánchez-Arcilla, C. Mösso, J. P. Sierra, M. Casas Prat

Laboratori d’Enginyeria Marítima, UPC

Centre Intern. d’Investigació dels Recursos Costaners

Catalonia coastline length: ~ 700 kmHigh geodiversity

500 m fringe

6.9% total area

48% population

26 Dec 2008 storms

HAZARDS UNDER PRESENT CLIMATE.

WIND – WAVES + STORM SURGES

The solid discharge reduction in the last century is of ≈ 1% of that in 1900, much more than for the liquid discharge

Comparación de las

diferentes estimaciones para la carga sólida del río Ebro durante

el siglo XX1900 1925 1950 1975 2000

tiempo (años)

0.1

1

10

100

ca

rga

só

lid

a (

10

6 T

m/a

)

Ibañez et al

Gorría Palanques et al

Catalán

Varela et al

(entrada)

Varela et al

(salida)

Palanques et al

(entrada)

Palanques et al

(salida)

Palanques Guillén &

Palanques

Critical Ql to transport the sand fraction at different sections down river

125 150 175 200 225 250

d50 ( mm)

360

380

400

420

440

460

Qcr (m

3/s

)

sección Tramuntano

sección Garxal

Mean duration of moderate ( Hs ≥ 1.5m) and severe ( Hs ≥ 2.0m) storms

(left) and number of storms (right) for the same two event types. Both panels

correspond to observed wave series off the Ebro Delta coast

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006year

10

15

20

25

30

35

du

ratio

n o

f sto

rms (

hrs

.)

Mean Duration of StormsHs=1.5

Hs=2.0

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006year

0

5

10

15

20

25

30

35

40

45

50

55

nu

mb

er

of sto

rms

Number of StormsHs=1.5

Hs=2.0

1960 1965 1970 1975 1980 1985 1990 1995 20000

2

4

6

8

10

12

Year

E (m

2d

ay)

Annual mean Energy

LR to ln(E|storm)

LR to ln(E|storm)*p(storm)

1960 1970 1980 1990 2000 2010 2020 2030 2040 20500

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Year

Frequency

Node 31 (S-wards direction)

Evolució temporal de la freq. anual

de les tempestes del S. Extrap. al

2050 amb interv. de conf. del 95%.

Tendència de l’energia de

tempestes d’onatge provinents

de S per a la costa catalana

Yearly mean hind-cast Hs values for the Gabès (left) and Catalan (right)

coasts. Data provided by the Ministère de l’Equipement et l’Habitat for

Tunisia and by the Ministry of Public Works for Spain

1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994

1

2

3

4

5

6

Wave H

eig

ht

(m)

1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

2

4

6

8

10

Wa

ve

Heig

ht

(m)

Measured MSL – storm surges – (without astronomic tidal component)

at the the Gabès Gulf (left, monthly mean, 1999 - 2008) and at the

Barcelona harbour (right, yearly mean, 1992 - 2007)

Storm surges at the Ebro coast in Spain. Hindcast time series

(1958-2001) showing a slight decreasing trend, while for the

last decade there is an increasing trend.

Holocene MSL for the Ebre delta and

adjacent spanish coast (Somoza et al., 1998)

Storm surge PDF off the Ebre delta under present conditions

and for a RSLR of 0.46 m corresponding to year 2100. For a

surge of 1.40 m, goes from 77 years down to 6.5 years

1 10 100

Return period (years)

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

Su

rge

he

igh

t (m

)

present

with a SLR of +0.46 m

Coastal rigidity (no retreat) + over-wash deposits after storm impact (“marine” flooding) in November 2001

Coastal retreat + overwash deposits after storm impact(“marine” flooding) in November 2001

Distribución probabilística conjunta de altura de ola significante (Hs) y nivel medio del mar

(Z). Nota: el asterisco (*) indica las condiciones que rompieron la barra del Trabucador

Storm impact in the

Trabucador bar (left).

Breaching after the

impact of the Oct/1990

storm (middle) &

breaching after the Nov/

2001 storm (right).

Annual mean (yellow), maximum (red) and minimum (blue)

SST at the Northern Catalan Coast (Estartit), 1969-2008 (left)

1970 1975 1980 1985 1990 1995 2000 2005 2010Year

14

15

16

17

18

19

20

Te

mp

era

ture

ºC

Estartit Yearly Averaged Mean, Min and Max Temp.Yearly Averaged Mean Temperature

Yearly Averaged Max Temperature

Yearly Averaged Min Temperature

and monthly SST in front of the Ebro delta, 1990-2008 (right).

Data from Servei Meteo. de Catalunya & J. Pascual.

Erosion (horizontal meters of shore-line retreat) due to SLR + storm

effects for the last century (Recent Past), present conditions (Present)

and by the year 2100 (Near Future). Sites without subsidence (No Sub)

and with subsidence (Sub). Uncertainty in the estimates should be

considered.

Consequences/Impacts

Percentual variation in water quality (WQ) driven by temperature (T) changes

for present conditions and by the year 2100 (denoted as Near Future). Values

of average variation (100 years interval) in SST and WQ are shown

simultaneously (SST / WQ) for the present conditions and the accelerated rate

due to climate change . The uncertainty in the estimates should be always

considered.

Consequences/Impacts

Llobregat Delta

HAZARDS UNDER FUTURE & PRESENT CLIMATE.

FLOODING + SUBSIDENCE (NEW INFRASTRUCT.)

Lloret, NE Med Spain

HAZARDS UNDER FUTURE & PRESENT CLIMATE.

NARROW POCKET BEACHES (URBAN)

Barna, Port Olimpic

HAZARDS UNDER FUTURE CLIMATE.

NARROW ARTIFICIAL BEACHES (+ LCS)

Altafulla beach Barceloneta beach

Indicadors robustes – Estat ZC

- Erosió NMM (+ Subsidència)

- Inundació Onatge (HS, D, θ, freq.)

- WQ Tw,

Pluviometria (freq, D, Vol)

“Darrers” anys (≈ 20 anys)

a) - No tempestes onatge sever ↑

- Erosió, Inundació ↑

CONCLUSIONS

Futur proper (≈ 50 anys)

b) - HS ↓

- Tempestes onatge del S ↑

- Canvi de θ (trajectòries temp. cap al N)

- Reorientació costa ↑ (costes “rígides” + erosió)

(e.g. Maresme)

-- Agitació ports

c) - NMM (storm surge) ↑

- Erosió, Inundació ↑

- Zones baixes i amb subsidència (e.g. Deltes)

CONCLUSIONS