Coast Management From the Viewpoint of Vegetation

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Coast Management - From the Viewpoint of
Vegetation -

• Akihito SAKURAIForest Engineer, JFEC, Japan

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The 26 December 2004 Tsunami in the Indian Ocean
Damages in Sri Lanka
Affected Persons Situation Map (08 Jan 2005)
Matala (South-western coast)
Photos Forest Department, Sri Lanka
Source MapAction
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The 26 December 2004 Tsunami in the Indian Ocean
Damages in Sri Lanka
Batticaloa (East coast)
Trains caught in the tsunami and derailed
(Telwata, South-western coast)
Galle (South coast)
Photos Lefts and right above Forest Department,
Sri Lanka, right below JFEC
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Coastal Area

• Border area between the sea and the land

- Multi-Purpose Utilization
Living area Commercial area Tourism area
Fishing area etc.
(Houses)(Shops, Markets, Offices, Hotels,
etc.)(Sandy beach, Natural beauty, Leisure
facilities, etc.)(Fishing / collecting area,
Breeding areas, Ports, etc.)
- Rich Natural Environment
Geography Biodiversity Habitat etc.
(Sandy beach, rocky beach, cliff, etc.)(Fauna
flora, Under the water / on the terrestrial
area)(Egg-laying area, Hatching area, etc.)
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Natural Disasters (1)
Coastal Area Border area between the sea and
the land

• -gt Easy to be suffered from natural disasters
  caused by (sea) water / wind
• -gt Easy to be suffered from typhoons / cyclones
  that break out over the sea

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Natural Disasters (2)
Coastal Area Border area between the sea and
the land

• From the sea side-gt Typhoons, cyclones (rain and
  wind)-gt High tides-gt Tsunami
• From the terrestrial side-gt Flying sand from
  sandy coasts / coastal sand dune toward
  inland-gt Inflowing sand into the sea

Seasonally / Occasionally
Rarely
Constantly
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Examples Damages on the areas where no measures
implemented

• Sandy beach (ex. Coastal area in Sri Lanka)
• Tsunami directly attacked

• Infrastructures heavily damaged
• Living environment worsened

Photo Forest Department, Sri Lanka
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Examples Damages on the areas where no measures
implemented

• Coastal sandy areas (ex. Coastal area in Vietnam)
• Strong winds caused sand flying-gt Flying sand
  inland-ward

• Living environment worsened
• Roads covered by sand
• Volume of agriculture production decreased

Photos Ministry of Agriculture and Rural
Development, Vietnam (JFEC). Implemented by
Japans Grant Aid
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Examples Damages on the areas where no measures
implemented

• Cape / point (ex. Erimo Cape in Japan)
• Heavy wind directly attacked-gt Flying sand
  inland-ward / inflowing sand into the sea

• Living environment worsened
• Volume of fishery production decreased

Situation in 1950s
Photo Hokkaido Regional Forest Office
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Examples Damages on the areas where no measures
implemented

• Coastal area (ex. Akita in Japan)
• Heavy wind directly attacked-gt Flying sand
  inland-ward / inflowing sand into the sea

• Living environment worsened
• Volume of fishery / agriculture production
  decreased

Photos Tohoku Regional Forest Office and Akita
Prefecture
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Countermeasures needed

• To prevent damage from flying sand for
  improvement of daily life
• To prevent damage from inflowing sand into the
  sea / river to prevent from pollution
• To prevent damage from tsunami disaster in the
  future

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Measures mainly implemented

• Artificial Coastal Protection Measures (Hard-Type
  Measures)Coast embankment, Breakwater /
  Seawall, Revetment, etc. (For tsunami / high
  tide disaster)
• Vegetational Coastal Protection Measures
  (Soft-Type Measures)Windbreak fences / Net,
  Soil conditioner / Soil amendments, Artificial
  sand dunes, Windbreak forest, etc. (For flying
  sand / inflowing sand)Mangroves (for erosion
  control)

• Mainly made by concrete
• Environment-unfriendly

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Examples Measures Implemented

• Coast embankment, Breakwater / Seawall,
  Revetment (For tsunami / high tide disaster)
  Maldives

Photos TAISEI Corporation Implemented by
Japans Grant Aid
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Examples Measures Implemented

• Mangroves (For tsunami / high tide disaster)
  India

The Asian Tsunami A Protective Role for Coastal
Vegetation(F. Danielsen, et al. (2005),
Science, Vol. 310) area with coastal tree
vegetation were markedly less damaged than areas
without. suggest that mangroves and Casuarina
plantations attenuated tsunami-induced waves and
protected shorelines against damage.
Source Science, Vol.310, 2005
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Examples Measures Implemented

• Coastal forests and sand dunes (For tsunami /
  high tide disaster) Sri Lanka

Coastal windbreak forest of Casuarina
equisetifolia
Coastal windbreak forest by Casuarina
equisetifolia and Pandanus sp.
Photos JFEC
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Examples Measures Implemented

• Reforestation / Revegetation on the cape (For
  strong wind / flying sand / inflowing sand)
  Erimo Cape (Japan)

Reforestation of Pinus thunbergii surrounded by
sand control hedges
Fig. Transition of areas of revegetation by grass
and trees and catch volume
Situation in 1950s
Situation in 1990s
Source Hokkaido Regional Forest Office
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Examples Measures Implemented

• Reforestation on coastal sandy areas (For strong
  wind / flying sand / inflowing sand) Akita
  (Japan)

Sandy coast in 1900s
Coastal windbreak forest by Japanese Black Pine
(Pinus thunbergii) in 2000s
Source Tohoku Regional Forest Office
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Examples Measures Implemented

• Reforestation on coastal sandy areas (For strong
  wind / flying sand / inflowing sand) Vietnam

Casuarina equisetifolia
Acacia crassicarpa
1 year after planting
2 years after planting
Photos Ministry of Agriculture and Rural
Development, Vietnam (JFEC)Implemented by
Japans Grant Aid
2 years after planting
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Examples Measures Implemented

• Reforestation / Revegetation on inland deserts
  (For strong wind / flying sand) (Ningxia, inland
  China)

Bare desert
Square-shaped sand flow break using rice straw
Planting area 2 years after planting
Photos The State Forestry Administration, China
(JOFCA). Implemented by Japans Grant Aid
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Bad Influences by Moving Sand

• Flying sand toward inland from coastal sandy
  areas constantly
• Inflowing sand from coastal sandy areas into the
  sea constantly

• Productivity of agricultural products decreased
  by flying sand
• Productivity of fishery products decreased by
  inflowing sand
• Living environment worsened
• Biodiversity worsened

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How to stop sand flying / sand inflowing?

• Alleviate the velocity of the wind

-gt Artificial fences-gt Artificial sand dunes-gt
Windbreak forests

• Stabilize the surfaces of sand

-gt Sand flow breaks -gt Cover the surfaces of
sand by vegetation
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How to Alleviate Velocity of Wind?

• Windbreak forests

Coastal windbreak forests in Akita, Japan
Photo Tohoku Regional Forest Office
Source ed. Higashi
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How to Stabilize Surfaces of Sand?

• Cover the surfaces of sand areas by vegetation

Square-shaped sand flow break using straw and
vinyl sheet
Sand flow break and mulching by seaweed
Square-shaped sand flow break using rice straw
Photos The State Forestry Administration, China
(JOFCA). Implemented by Japans Grant Aid
Photos Hokkaido Regional Forest Office
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Conclusion

• Coastal windbreak forests and mangrove forests
  contribute to mitigate damages / pollutions
  caused by sand moving.
• Forests on-/along-shore have possibility to
  reduce tsunami power and protect shorelines from
  damages.
• Forests are helpful in preserving biodiversity
  and improving environments.

Lets conserve and establish coastal forests and
mangroves to protect our LIVES!
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Recommendations

• Any measures do not have effect on damage /
  disaster prevention on 100.
• Important to realize how decrease damages /
  pollutions caused by natural disasters.
• Suitable combination of hard facilities
  (concrete-type) and soft facilities
  (vegetation-type) should be planned.
• Coordination of land usage by sectors should be
  managed in planning / implementing.
• Watershed management, from mountainous areas to
  the sea through rivers, is important.
• Further research for functions on soft facilities
  (vegetation-type) as damage / disaster prevention
  should be needed.

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Thank you for your attention!

• If you have any question,Please e-mail to
  mr_aki.sakurai_at_nifty.com

New Georgia Islands, Solomon Islands (A. Sakurai)