Climate Change in Mekong River Basin and Hypothetical Impacts on Water Related Sectors:

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Climate Change in Mekong River Basin and
Hypothetical Impacts on Water Related
Sectors AS07 Preliminary finding and future
study direction Suppakorn Chinvanno  Southeast
Asia START Regional Center Old SWU Pathumwan 5
Building, 5th Floor Chulalongkorn
University Henri Dunant Rd., Bangkok 10330
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Agenda

• Study of Climate Change in Mekong River Region
• Output from Regional Climate Modeling
• Impact of Climate Change in Mekong Region Future
  Precipitation
• Climate Change Impacts on Water Related Sectors
  Mekong Region
• Hypothetical Conclusion on
• Agriculture
• Water Supply
• Human Settlement Urbanization
• Natural Wetland
• Future Study Framework Direction

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Study of Climate Change in Mekong River Region
China
The study of climate change in Mekong River Basin
will base on scenarios of GHG in earth
atmosphere, particularly - CO2 This study is
based on 2xCO2, scenario and will also include
1.5xCO2 scenario in the future.
Viet Nam
Myanmar
Laos
Thailand
Cambodia
Mekong River Basin
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Study of Climate Change in Mekong River Region
Regional Climate Change Study Modeling Approach
Atmospheric Research Climate Modeling

• Regional climate model used Conformal Cubic
  Atmospheric Model (CCAM)
• The output resolution was set at 14 km.

Stretched coordinate system for CCAM modeling of
the Mekong basin
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Output from CCAM Regional Climate Model Changes
in rainfall throughout the Mekong region
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Impact of Climate Change in Mekong Region
Future Precipitation
Summary of CC Impact on Precipitation by Landform

• Lancang Basin - less rainfall throughout the
  year by 20

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Impact of Climate Change in Mekong Region
Future Precipitation
Summary of CC Impact on Precipitation by Landform

• Northern Highland
• Significantly increase of rain at the latter
  part of rainy season

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Impact of Climate Change in Mekong Region
Future Precipitation
Summary of CC Impact on Precipitation by Landform

• Korat Plateau Season change.
• Slightly shorter but more intense toward the end
  of rainy season
• Longer and dryer dry season

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Impact of Climate Change in Mekong Region
Future Precipitation
Summary of CC Impact on Precipitation by Landform

• Eastern Highland Season change
• Longer and dryer dry season
• Shorter and wetter rainy season

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Impact of Climate Change in Mekong Region
Future Precipitation
Summary of CC Impact on Precipitation by Landform

• Lowland Change in season pattern
• Longer and dryer dry season
• Shorter and wetter rainy season

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Climate Change Impacts on Water Related Sectors
Mekong Region

• CC Impacts on 4 major water related sectors
• hypothetical conclusion
• Agriculture (impact on rainfed rice cultivation)
• Water Supply (impact on water quantity/quality)
• Human Settlement and Urbanization (impact on
  flood/infrastructure)
• Natural Wetland (impact on biodiversity)

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Climate Change Impacts on Water Related Sectors
Mekong Region
Agriculture

• Rainfed agriculture in Lancang landform will be
  highly affected by total reduction in
  precipitation.
• Impact on rain-fed rice cultivation in most part
  of lower Mekong region from seasonal shift and
  change in rainfall pattern.

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Climate Change Impacts on Water Related Sectors
Mekong Region
Water Supply

• Significant reduction in water supply in upper
  Mekong--Yunnan--but may be less erosion
• Some water shortage in dry season in most
  southern landforms due to longer and dryer season
• Deteriorated water quality--salinity,
  acidification, etc.-- in some areas due to
  reduced flushing during dry spells

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Climate Change Impacts on Water Related Sectors
Mekong Region
Human Settlement and Urbanization

• Potential for more intense and longer flood in
  Korat Plateau and Southern Lowland, especially in
  September and October

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Climate Change Impacts on Water Related Sectors
Mekong Region
Natural Wetland

• Possibility for drying-out of some wetlands in
  Lancang landform
• Impact on migratory species caused by change in
  water regime in wetland due to the change in
  rainy season pattern. Possibility in most of
  lower part of Mekong region.
• Treat to wild fish stock and capture fishery,
  especially in the Korat Plateau and southern
  Lowlands.

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Future Study Framework Direction
Problem Definition (e.g. potential climatic
variations, historical events)
Project Scoping (e.g. study area, sectors,
scenarios)
Impact Assessment (integrated impacts analysis)
Adaptation Assessment (options, adaptive capacity)
Integrated Vulnerability Assessment
Adaptation Strategies to Reduce Vulnerability
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Future Study Framework Direction
Impact of climate change on precipitation and
downstream effect on water resources

• Possible change in the future rainfall pattern
  and shifting of the season
• Impact on future runoff and river flow from the
  future rainfall pattern
• Impact on future frequency, length and magnitude
  of flood
• Impact on future frequency, length and magnitude
  of drought

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Future Study Framework Direction
Regional hydrology study modeling approach
SEA BASINS
SEA BASINS VIC Hydrological Model for Mekong
Basin
Drainage
Soil
Land Cover
Elevation
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Future Study Framework Direction
Regional hydrology study modeling approach
SEA BASINS
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Future Study Framework Direction
Regional hydrology study modeling approach
SEA BASINS
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Future Study Framework Direction
Agriculture

• Use satellite image to determine rice field.
• Then, use crop model DSSAT to study rice yield
  under future climate scenarios.
• Assess community vulnerability from the change of
  rice production evaluate impact in terms of
  rice production as indicator of food intake for
  household and source of income.
• Assessment to be done at the sub-basin level.

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Future Study Framework Direction
Water Resources

• Simulate the water profile from SEA-BASIN VIC
  model
• Assess community vulnerability by evaluate the
  supply of water and match the usage pattern by
  various sectors in the Mekong River region,
  perhaps to use frame of MRC-WUP as guideline
• Also study the impact of changing in water regime
  toward the salinity particularly in NE of
  Thailand

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Future Study Framework Direction
Human Settlement and Urbanization

• Study the tendency of increasing of frequency and
  magnitude of flood in the region from climate
  variability.
• Evaluate the vulnerability from the damage that
  future flood may cause perhaps to use the frame
  and information from MRC-Flood Forum as guideline

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Future Study Framework Direction
Aquatic Ecosystems

• Study the impact of CC on the product and
  services from the ecosystems that community rely
  for their well-being plan to focus on the
  habitat for migratory species, particularly fish
  which is captured for food
• Assess community vulnerability from wild fish
  stock and capture fishery as this is main source
  of food intake for the household as well as
  source of income.
• Assessment to be done at the sub-basin level

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Discussion Session
Thank You