Unit 7 Case Study: East Coast USA

Question 1

Background

Answer 1

Sea levels along the East coast have risen faster than the global average due to land subsidence in some areas and warming ocean temperatures. Hurricanes have highlighted the urgent need for effective coastal defence. The long term impacts of erosion are central to coastal management

Question 2

Seawalls

Answer 2

Have been the dominant approach and are built to protect urban areas, ports and other critical infrastructure from wave action and storm surges
Effects of Superstorm Sandy in New York and New Jersey led to seawalls and barriers. The $1.45bn Staten Island seawall was designed to shield communities from storm surges. They were effective in reducing the immediate flood risk to vulnerable neighbourhoods but may contribute to beach erosion and negatively impact ecosystems. In some places they transfer wave energy to adjacent areas causing faster erosion and habitat loss

Question 3

Groins and jetties

Answer 3

Widely used to prevent sediment loss from the shore. They have stabilised beach areas along the Carolinas and Florida but success is localised and have increased erosion on adjacent beaches by interrupting natural sediment flow. Some communities have therefore used groins with beach nourishment to mitigate side effects

Question 4

Beach nourishment

Answer 4

Offers and environmentally friendly alternative by recreating natural processes which is important for tourism. Sand is often sourced from offshore dredging, harming marine life. Replenished sand is eventually washed away so requires ongoing intervention. The increasing frequency of intense storms may make this not sustainable in the long run

Question 5

Beach nourishment Miami and Carloinas

Answer 5

In Miami Beach and Outer Banks beach nourishment has been successful. In the 1980’s Miami’s $400m beach nourishment project started and is still effective in maintaining wide, sandy beaches that are tourist attractions and nature buffers against storm surges. The replenishment of sand has reduced the need for repairs after hurricanes and mitigated some impacts of sea level rise. In North and South Carolina it has helped restore tourism dependent areas. Nags Head has had several $25-40m projects

Question 6

Dune restoration

Answer 6

Dunes act as natural barriers against storm surges and erosion and play a vital role in protecting inland areas. In New Jersey after Superstorm Sandy dune restoration was a priority. Long Beach Island was also a successful project where new dunes helped prevent further damage from later storms. This is also environmentally friendly because it enhances coastal habitats. It has been especially successful in Cape Cod where dunes have been stabilised and wildlife supported. Still requires long term maintenance and monitoring

Question 7

Managed retreat

Answer 7

Involves relocating buildings and infrastructure away from vulnerable coastal areas. A last resort method but useful in some communities. Parts of Staten Island have undergone this after Superstorm Sandy. The state offered homeowners market value for their property so they could move to safer areas. Over 500 houses were bought and destroyed. There is a reduction in future flood risks but is both controversial and emotional
Has also been implemented in rural areas of Virginia’s’ Eastern Shore and parts of coastal South Carolina. There is still resistance due to the social, economic and political implications. Coastal residents tend to prefer engineered solutions even if only temporary