Natural Barriers and Storm Protection

1
Natural Barriers and Storm Protection
Saudamini Das Institute of
Economic Growth Delhi
University, Delhi
UNEP-UNDP-SANDEE-PC of Bangladesh Workshop on
Climate Change Dhaka, 14th October, 2009
2
Outline of Presentation

• Should we preserve Our Natural Barriers to
  mitigate the effects of Climate Change ( Is
  there economic justice) ?
• Examine the above question in the context of
  Storm Protection Services of Mangroves.

3
(No Transcript)
4
Services of Mangrove Ecosystem

• Provisioning
• Supporting
• Regulating
• Cultural

Source Millennium Ecosystem Assessment
5
Services of Mangrove Ecosystem
1. Provisioning
Firewood Charcoal Construction material (timber,
poles, Nipa singles) Mangrove propagulas Fodder Gr
een maneuver Cellulose for paper Food, beverages
and drugs (sugar, alcohol, medicines)
Tannies and dyes Finfish Crustaceans (Prawns,
shrimps, mangrove crabs). Malluses (cryster,
mussels, cockles) Honey Birds Mammals Reptiles Wat
er transport

6
2. Supporting Ground water discharge, Prevention
of soil salinity, Sediment/Toxicant
retention, Nutrient retention, Nursery ground for
fish fry, Biomass export, Water transport,
3. Regulating Flood control, Storm
protection/wind break, Shoreline stabilization
and erosion control, Micro climatic
stabilization, 4. Cultural Biological
diversity, Unique to culture/heritage, Recreation/
Tourism.
7
Problem Area..
1. Important Services are

• Indirect,
• Invisible,
• Occur off site
• Unknown to policy maker

2. Mangrove land are Prime sea front, high on
demand and have high value alternative uses.
8
Mangroves inter-tidal forests
http//www.nio.org/Biology/mangrove/MANGCD/fig4.gi
f
http//www.vub.ac.be/ANCH/CV/steven.html
9
Storm Protection Services of Mangroves

• Debated since the Bhola Cyclone (Nov 1970)
• in Bangladesh (East Pakistan) (Bio
  Conserv, 1971).
• Recently in limelight due to prominent natural
  disasters like 2004 tsunami, Hurricane Katrina,
  Rita, Cyclone Sidr, Nargis, Alia etc.
• Is likely to be more important with climate
  change.
• Very few studies and micro level analysis of
  cyclone impact is missing.

10
Existing Literature

• Mangrove protection during tsunami
  

• Mangroves reduced tsunami damage
• No mitigating effect of vegetation on tsunami
• Role of mangroves as potential tsunami buffer
  could be fairly minor

• Mangrove protection during Cyclones

• Only four studies so far.
• But there are methodological concerns.

• No clear answer on storm protection role of
  Mangroves

11
Study Area (Kendrapada District-Cyclone prone)
Kendrapada
Arabian Sea
Bay of Bengal
12
Kendrapada District in Super Cyclone of Oct 1999
Kendrapada
13
(No Transcript)
14
Super Cyclone 1999

• T7 Category, Landfall Wind Velocity 256 kmph,
  Maximum Height of Storm surge 7 meter
• Battered 12 of the 30 districts of the eastern
  Indian State of Orissa
• Remained nearly stationary within the state for
  3 days
• Caused 9893 human death, 441531 livestock
  loss, 1958351 damaged houses, 1843047 hectares of
  damaged crops etc,

15
http//cache.eb.com/eb/image?id81553rendTypeId4
http//www.foodrelief.org/news/articles/4/1/Super-
Cyclone-in-Orissa-India
http//v3.osdma.org/Photogallery.aspx?vchglinkidG
L025
16
Overview of present study

• Analyzed role of Mangroves in impacting damages
  during the Super Cyclone in Kendrapada
• Detailed statistical analysis of Village wise
  Storm Damages
• Large sample many variables to separate out
  Mangrove effect
• Simulated cyclone impact assuming (1) if there
  were no mangroves and (2) if mangroves were not
  destroyed at all

17
Method - Cyclone Damage Function

Di f (Pi, Vi , Wi, Si)

• Types of Damages (Di)

• - Human Death
• House Damages
• - Livestock Loss

• Factors affecting cyclone damages

• Population or Property at risk (Pi)
• Wind Velocity (Vi)
• Velocity of Storm Surge (Wi)
• - Socio-economic Well being (Si)

18

Mangrove Forest Cover in 1950 (30,766 ha) and
the Cyclone path
Bhadrakh
Kendrapada
Jagatsinghpur
Super Cyclone Path
Bay of Bengal
Puri
19
Mangrove Forest Cover in 1999 (17,900 ha) and
the Cyclone path
Bhadrakh
Kendrapada
Jagatsinghpur
Super Cyclone path
Bay of Bengal
Puri
20
Kendrapada
District - Present mangrove,
Road, Railway and River network
Bhadrakh Dist.
North
Bay of Bengal
Jagatsinghpur Dist
21
Factors other than Mangroves

• Physical features of mangrove habitat areas
• Cyclone Impact
• Topography
• Hydrology
• Infrastructure
• Socio-Economic Well-being
• Governmental Institutions

22
Human death in Kendrapada
23
Description of Deaths
24
Deaths Averted by Mangroves

,
25

Percentage of Damages averted by Mangroves
26
Storm Protection Value of Mangroves during super
cyclone
27
Few other significant findings

• In the storm surge affected areas, people with
  more immovable assets seem to have died more
  compared to people with low asset holding ? need
  for property insurances?
• The villages situated near the dykes look to have
  witnessed more swept away houses and more loss of
  livestock, but less human death.
• The villages situated in mangrove habitat areas
  and people without regular jobs (marginal
  workers) are found most vulnerable.They need
  complete evacuation before a high intensity
  cyclone.

28
Should we preserve mangroves to mitigate effects
of climate change?

• Yes on both meteorological and economic grounds.
• 
  Meteorology
• Orissa is the most cyclone prone state in east
  coast.
• Frequency of high intensity cyclones increasing
  over years.

29
Economic Logic (1999 prices)

• Opportunity cost of protecting mangroves -
• - Market value of land in coastal Kendrapada
  Rs1, 72, 970 \ ha
• - Annual return (8) from land
  Rs13, 837 \ ha \ yr
• - (12)
  Rs20, 756 \ ha \ yr

• Benefit from retaining mangroves -

• Storm protection value (only for 3 damages)
  Rs1, 82, 080 \ ha
• Annual Probability of VSCS and SC
  0.15 \ yr
• Annual Storm Protection Value (3 damages)
  Rs27, 312 \ ha \ yr

Benefit gt Cost
30
Does reduction in risk of death only justify
mangrove preservation?

• Benefit from death reduction -
• - No of lives saved
  0.01 \ ha
• - VSL for Orissa from Indian wage-risk study
  Rs10, 918, 132 \
• - Annual probability of VSCS SC
  0.15 \ yr
• - Annual value for reduction of death risk
  Rs17, 469 \ ha \ yr
• Opportunity cost of Mangrove Protection
• 
  Rs13, 837 Rs20, 756 \ ha \ yr
• Benefit Cost

31
Are all coastal villages equally vulnerable?

• Analysed 262 villages within 10 km of coast
• Ranked the villages on the basis of probability
  of death

32
(No Transcript)
33
What Impacts Vulnerability more?
34
Conclusion

• Mangroves reduced human death, loss of livestock
  damages to residential houses during super
  cyclone.
• Human death toll would have been nearly doubled
  in absence of mangroves.
• Annualized storm protection benefit of mangrove
  for reducing only 3 damages is higher than annual
  return from land.
• Mangroves provide protection to other properties
  and other benefits as well.
• Both Climate Change and Economics justify
  mangrove preservation.

35

THANK YOU