satesh workshop southasia journalists 27 aug09
DESCRIPTION
Science and impacts of climate changeTRANSCRIPT
Science and impacts of climate change
• Satheesh C. Shenoi• Indian National Centre for Ocean Information Services
(INCOIS)• Ministry of Earth Sciences• Hyderabad – 500 055• [email protected]
Centre for Science and Environment South Asian media briefing workshop on climate change 27-28 August 2009, India Habitat Centre, New Delhi
Sea levels are rising worldwide and along much of the South Asian coast. (IPCC, 2007). Tide gauge measurements and satellite altimetry suggest that sea level has risen worldwide approximately 4.8-8.8 inches (12-22 cm) during the last century (IPCC, 2007). A significant amount of sea level rise has likely resulted from the observed warming of the atmosphere and the oceans.
Annual averages of global mean sea level
• Reconstructed Sea level (red)
• (Church, White)• TG Measured • Since 1950
(blue)• Altimetry (black) Figure 5.13
Sea Level Trend Shoreline Change Rate
Long Term Sea Level Data from tide gauges
Satellite and Secondary data
DEM dataReturn periods (T)Extreme water level (Hmax)
Future Sea Level after T (A) Future Shoreline after T (B) Contours
Multi-hazard Line=A>B>C
Contour of Hmax (C)
Methodology for multi-hazard coastal vulnerability
Multi-hazard Map
20m
5m
10m
Coastline in 1950
Coastline in 2005
Predicted erosion in 100 yrs
Predicted 100 year flood level
Composite 100 year hazard line
Illustration of Methodology
Parameters Considered•Shoreline change (Landsat data 1972-2000)•Probability of extreme water level in a return period (Observed Tide data)•Contours (ALTM & Carto-DTM)
Mean-sea-level-rise trends along the north Indian Ocean coasts from past tide-gauge records
Estimated trends vary from 1.06 to 1.75 mm/year for individual records (an average of 1.30 mm/year) Unnikrishnan and
Shankar (2007)
Net sea-level-rise trends
Station No of years
Trends (mm/yr)
GIA (mm/yr)
Net sea level rise (mm/yr)
Aden 58 1.21 -0.16 1.37
Karachi 44 0.61 -0.45 1.06
Mumbai 113 0.77 -0.43 1.20
Kochi 54 1.31 -0.44 1.75
Vishakhaptnam
53 0.70 -0.39 1.09
Diamond Harbour
55 5.22 -0.52 5.74
Return period of the extreme water levels
Return Period of the extreme water levels for the Nagapatnam
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
5 15 25 35 45 55 65 75 85 95
Return Periods (Y)
Wat
er L
evel
(m
)
Return Period of the extreme water levels for the Chennai
1.50
1.55
1.60
1.65
1.70
1.75
1.80
1.85
1.90
1.95
2.00
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
Return Periods (Y)
Wat
er L
evel
(m
)
Gringorten distribution technique p12.0
44.0
88.01
44.0
N
m
N
m
)
R
1-(1loglogauU eeExtreme value distribution
Calculation of the reduced variate y = - loge (-loge p)
•1.94-1.55 meters of extreme water level for the return period of 100 years•2 meter has been considered for the current study
Ca
lcu
lati
on
of
Sh
ore
line
Ch
an
ge
Ra
te (
197
2-20
00)
Lan
dw
ard
Sh
ore
lin
e af
ter
100
year
Mu
lti-
haz
ard
Map
of
Cu
dd
alo
re A
rea
Co
mp
osi
te M
ult
i-h
azar
d l
ine
ove
rlai
d o
n t
he
Go
og
le E
arth
Zoomed area of the Cuddalore Town
Multi-hazard vulnerability map of Nellore district, Andhra Pradesh
Return Period of the Extreme Sea Levels
0.002.004.006.008.00
10.0012.0014.0016.0018.00
Che
nnai
Bha
vana
gar
Coa
chin
Dia
mon
d
Gan
gra
Gar
den
Hal
dia
Kan
dla
Kar
war
Man
galo
re
Mar
mag
oa
Min
icoy
Mum
bai
Nag
apat
nam
Okh
a
Par
adee
p
Por
t B
lair
Sag
ar
Trib
eni
Tut
icor
in
Vad
inar
Ver
aval
Vyz
ag
Stations
Wat
er L
evel
(m
) y5
y10
y25
y50
y75
y100
Return Period of the extreme water levels for the Chennai
2.50
3.00
3.50
4.00
4.50
5.00
5.50
6.00
5 15 25 35 45 55 65 75 85 95
Return Periods (Y)
Wat
er L
evel
(m
)
* 236 villages are under the multi-hazard line
S. No ParameterLength (km)
Low Medium High
1 Shoreline change rate 231 194 55
2 Significant wave height 0 480 0
3 Sea-level change rate 23 166 292
4 Tidal range 141 302 37
5 Coastal regional elevation
91 182 207
6 Coastal slope 10 41 429
7 Tsunami run-up 31 327 121
8 Coastal geomorphology 39 74 367
9 CVI 76 297 107
Srinivasa Kumar T, Mahendra R S, Shailesh Nayak, Radhakrishnan K R and Sahu K C, “Coastal Vulnerability Assessment for Orissa Coast”, 2009, Journal of Coastal Research, Accepted
Coastal Vulnerability Index for the Orissa Coast
0.8 °C 0.4 °C
Source- http://worldviewofglobalwarming.org
80 ppm of CO2 concentration due to human contributions!
7.7° F300 ppm
380 ppm
Major polluters
?