coastal property damage mitigation risk assessment geol 4093
TRANSCRIPT
Coastal Property Damage Mitigation
Risk Assessment
GEOL 4093
Mitigation
• Engineering– Strengthen or move buildings– Armor the coast
• Land Use Planning– Limit or reduce development density– Can help implement new techniques such as
clustered housing– Easiest with new developments
Responses to an Eroding Shoreline
• Hard Stabilization– Seawalls, groins, breakwaters, etc.
• Soft Stabilization– Beach replenishment, dune building
• Relocation or retreat– Move back from eroding shoreline
Hard Stabilization (Seawalls, etc.)
• Advantages– Most dependable way to save beachfront
property
• Disadvantages– Degrades the recreational beach– Reduces beach access– Costly– unsightly
New Jerseyization
Modes of Beach Destruction by Seawalls
• Placement Loss– Seawall is built on the recreational beach
• Passive Loss– Beach continues to retreat and narrows in front
of the seawall
• Active Loss– Seawall directly causes erosion
Metropolitan San Juan Dry Beach Widths
Soft Stabilization (Beach Nourishment)
• Advantages– Widens the beach– Protects buildings while beach is in place
• Disadvantages– Temporary– Costly– Unknown environmental effects
Relocation or Retreat
• Advantages– Responds to sea-level rise
– Preserves the beach
– Saves shoreline stabilization costs
– Preserves builidings
• Disadvantages– Politically difficult
– Potentially costly
– Loss of land
Mitigation Options
• Hard Stabilization
• Soft Stabilization
• Vegetation
• Development and infrastructure
• Zoning and land use planning
Our Approach to Mitigation
• Coastal landform protection, restoration, augmentation
• Mostly low cost
• Many things individuals can do
• Environmentally sensitive
• Considers geologic/oceanographic processes
PAR For the Shore
• Preserve, Augment, Restore– Dunes (frontal and interior)– Coastal barriers of all types
• Mangroves
• Shoals
• River mouth bars
• Maritime forest
– Add new sand to island
Pandora’s Island—Mitigation on the Beach
Pandora’s Island—Mitigation back from the beach
Pandora’s Island becomes Fantasy Island