2.9A Local factors that increase Coastal flooding

• local factors increasing the risk of flooding:

  • height
  • subsistance
  • vegetation removal
• height:

  • Low lying coastlines are at risk of flooding
  • Temporary flood risk from storm surges, permanent flooding from global sea level rise
  • e.g. Bangladesh and Tuvalu
• Subsistance:

  • Low lying coastlines in estauries, deltas or outbuilding zones are subject to natural subsidence through the settling and compaction of recently deposited sediment
  • Deltas experience periodic isostatic subsidence 
• vegetation removal:

  • salt marshes and mangrove forest, reduces flood risk
  • Vegetation stabilises existing sediment and traps new sediment, raising the height of the land above sea level
  • Vegetation absorbs wave energy, reducing wave impact and erosion