MegaDeltas (MD)

Climate Change Impacts and Needs in Asia-Pacific Region
MegaDeltas (MD)
Changes in Climate Factors
  • Sea level rise
  • Increase in extreme events (tropical cyclones, storm surges, etc.)
  • Changes in precipitation
  • Increases in atmospheric and water temperatures
Primary Impacts
  • More severe flooding due to storm surge. Heavy rainfall
  • Inundation of low-lying areas, submergence of swamps and wetlands
  • Coastal erosion
  • Salt water intrusion, increased salinity of rivers, bays, and aquifers
  • Ecosystem changed (mangrove destruction, wetland ecosystem deterioration, etc.)
  • Formation of oxygen-deficient water layers and increased frequency and intensity of red tides
  • Increases in pathogens of water-borne diseases
Natural/Social Factors
  • Mega-deltas formed by rivers with large river flows (flattopography)
  • Ground subsidence by excessive groundwater withdrawal
  • Reduced sediment discharge due to reservoir construction, etc., upstream
  • Eutrophication
Secondary Impacts
  • Loss of human life due to extreme events. Worsened health due to increase in disease, etc.
  • Land loss (loss of habitable and industrial land)
  • Increased risk of infrastructure destruction and damage
  • Decreased productivity of productive centers and livability of habitable land due to increased flooding
  • Decrease in water resources
Natural/Social Factors
  • Concentration of population(in low-lying area where is under unsanitary condition and is not safe)
  • Concentration of economic activities
  • Concentration of infrastructure
  • Increase of flood risk in urban area (poor drainage)
  • Developed water transportation system
  • Different levels of coastal protection
  • Different levels of sanitary conditions
Needs and Changes
  • Projection/assessment of impacts/vulnerability
  • Measures against erosion and inundation (retreat by land use planning, defense by diskes, drain by improving infrastructure, etc.)
  • Measures against flooding, storm surges, etc. (avoid/minimize damage)
  • Conservation/securing of water resources
  • Measures to conserve soil/water quality for agriculture/fisheries
  • Sanitation measures (improve water treatment, enhance sanitation practices, etc.)
Note: Underlining indicates factors that apply especially to mega-deltas (and their megacities)