This project studied the vulnerability of the Bangladesh coastline to inundation under cyclones. It analyzed historical cyclone records for Sandwip Island, assessed current coastal erosion and land use changes using remote sensing, conducted surveys of physical characteristics, and interviewed local residents. Key findings were that large areas of the low-lying island are at risk of flooding from storm surges above 3-6 meters, agricultural land is being lost to coastal erosion and development, and residents have adopted some coping strategies but lack robust protection.
Data delivery from the US-EPA Center for Computational Toxicology and Exposur...
IAHR 2015 - Vulnerability of the Bangladesh coastline to inundation under cyclone activity, Ciavola, 30062015
1. This
project
has
received
funding
from
the
European
Union’s
Seventh
Programme
for
Research,
Technological
Development
and
Demostra>on
under
Grant
Agreement
No.
603458
Prof.
Paolo
Ciavola,
Università
di
Ferrara-‐CFR,
Ferrara,
Italy
cvp@unife.it
Vulnerability
of
the
Bangladesh
Coastline
to
Inunda>on
Under
Cyclone
Ac>vity:
Past
Records
and
DRR
Strategies
at
Sandwip
Island
P.
CIAVOLA
(UNIFE-‐CFR),
M.M.
UDDIN
(UNIFE-‐CFR)
,
E.
DUO
(UNIFE-‐
CFR)
,
B.
LEE
(WMO),
S.H.M
FAKHRUDDIN
(WMO)
2. 36th
IAHR
World
Congress
28
June
–
3
July,
2015,
The
Hague,
the
Netherlands
Problem
statement
3. 36th
IAHR
World
Congress
28
June
–
3
July,
2015,
The
Hague,
the
Netherlands
Problem
statement
Cyclones Tracking Over Bangladesh During the
Twentieth Century
Frequency
of
cyclones/severe
cyclones
over
the
Bay
of
Bengal
in
different
months
during
1891-‐2010
4. 36th
IAHR
World
Congress
28
June
–
3
July,
2015,
The
Hague,
the
Netherlands
Most
important
recent
events
Dura/on:
29-‐30
April,
1991
Damage:
widespread
damage
Death:
138,882
people
Total
Loss:
US
$
2.07
billion
Storm
Surge:
4-‐6
meter
Dura/on:
14-‐16
Nov,
2007
Killed:
3,406
peoples
Injured:
55282
Storm
Surge:
5-‐6
m
high
Source:
DDM
website
5. 36th
IAHR
World
Congress
28
June
–
3
July,
2015,
The
Hague,
the
Netherlands
Study
Site:
Sandwip
Island
• The
eleva>on
of
the
island
is
lower
than
5
m,
and
most
commonly
2-‐3
m.
Addi>onally,
the
sediments
making
up
the
islands
are
very
soh,
unconsolidated
silts
and
clays.
• Thus
the
landforms
of
the
ac>ve
delta
are
extremely
changeable
and
are
easily
reshaped
by,
>dal
ac>on,
river
discharge
and
ajack
of
cyclones
6. 36th
IAHR
World
Congress
28
June
–
3
July,
2015,
The
Hague,
the
Netherlands
• What
is
the
historical
records
of
cyclone
impact
on
the
island?
• What
DRR
measures
were
present
when
historical
events
occurred?
What
are
present
now?
• What
is
the
current
coastline
change
along
the
island?
• Set-‐up
of
an
opera>onal
Early
Warning
System
at
a
demostra>ve
level
using
DELFT-‐FEWS
• Calibra>on
of
the
EWS
following
installa>on
of
a
local
>de
gauge
and
repeated
surveys
• What
is
the
local
percep>on
of
people
occupying
the
island?
How
do
they
cope
with
disasters?
Research
ques>ons
7. 36th
IAHR
World
Congress
28
June
–
3
July,
2015,
The
Hague,
the
Netherlands
• Analysis
of
records
available
from
Bangladesh
ins>tu>ons.
• Topographic
survey
of
eroding
part
of
the
island
• Analyses
of
Landsat
imagery
(1978,
1989,
2001,
2006,
2014)
for
shoreline
change
and
land-‐cover
change
• ASTER
DEM
of
the
island
(30
m
resolu>on)
• Ground-‐truthing
of
DEM
with
comparison
with
surveys
• 43
interviews
to
key-‐end
users
from
the
island
and
150
interviews
to
local
residents,
focussing
on
the
percep>on
if
they
are
at
risk
and
how
they
cope
with
problems
like
coastal
erosion
and
cyclones
Methods
8. 36th
IAHR
World
Congress
28
June
–
3
July,
2015,
The
Hague,
the
Netherlands
Physical
Characteris>cs
(surveys)
808/07/15
9. 36th
IAHR
World
Congress
28
June
–
3
July,
2015,
The
Hague,
the
Netherlands
908/07/15
Cyclone surge level
Cyclone surge level
Cyclone surge level
Cyclone surge level
Cyclone surge level
Physical
Characteris>cs
(surveys)
10. 36th
IAHR
World
Congress
28
June
–
3
July,
2015,
The
Hague,
the
Netherlands
Evolu>on
of
the
island
(Landsat)
Year Difference
(km
2
)
Erosion
(Km
2
)
Erosion
Rate(km
2
/
yr)
Accretion
(km
2
)
Accretion
Rate km/y
1978-1989 -32.51 34.5 3.128 1.907 0.173
1989-2001 26.379 30.916 2.576 57.322 4.776
2001-2006 -11.955 23.133 4.626 11.286 2.257
2006-2014 -36.46 39.572 4.946 3.036 0.379
Erosion
Accre>on
11. 36th
IAHR
World
Congress
28
June
–
3
July,
2015,
The
Hague,
the
Netherlands
Land-‐use
change
(Landsat)
Occupa>on
growing
from
7%
(1989)
to
26%
(2001)
to
37%
(2014)
of
the
total
area
in
those
three
years
Agricultural
land
reduced
drama>cally
from
64%
in
1989
to
23%
in
2001
due
to
conversion
into
sejlements
12. 36th
IAHR
World
Congress
28
June
–
3
July,
2015,
The
Hague,
the
Netherlands
Coping
with
coastal
erosion
08/07/15 12
Erosion
08/07/15
13. 36th
IAHR
World
Congress
28
June
–
3
July,
2015,
The
Hague,
the
Netherlands
Surge
Flood
Risk
08/07/15
13
Noembankment
14. 36th
IAHR
World
Congress
28
June
–
3
July,
2015,
The
Hague,
the
Netherlands
Possible
cyclone
inunda>on
08/07/15
3 meter surge
height
91 / 227 (km2)
6 meter surge
height
171 / 227 (km2)
15. 36th
IAHR
World
Congress
28
June
–
3
July,
2015,
The
Hague,
the
Netherlands
Coping
with
cyclones
08/07/15 15
Erosion
08/07/15
Management
ac/ons
implemented
aGer
disasters
Construc>on
of
cross
dam
Island
encircling
embankment
Warning
system
accuracy
and
>mely
dissemina>on
Risk
relevant
educa>on
&
adapta>on
training
Transport,
health
and
communica>on
development
Community
Demands
16. 36th
IAHR
World
Congress
28
June
–
3
July,
2015,
The
Hague,
the
Netherlands
• Island
with
high
coastal
dynamics,
the
island
has
always
existed,
there
is
evidence
in
historical
documents
since
the
16th
century.
• In
the
1990s
changed
shape
extending
northwards.
The
1991
cyclone
might
have
played
a
role
in
this.
• In
the
same
period
there
was
a
change
in
land-‐use
conver>ng
agricultural
land
into
forest
and
there
was
an
increase
in
sejlements
in
the
western
part
of
the
island
• Simple
bath-‐tub
modelling
shows
that
this
is
the
area
most
vulnerable
to
cyclones
as
flooding
• Future
work
will
included
the
set-‐up
of
an
opera>onal
Early
Warning
System
at
a
demonstra>ve
level
using
DELFT-‐FEWS
Conclusions
17. Looking
forward
to
a
fruioul
coopera>on!
! !
Thanks
for
your
ajen>on
Accreting mudflat western side of Sandwip, February 2014