Case Study: Eastern Seaboard

Question 1

Problems

Answer 1

Hard methods = ineffective

• Sea walls and other hard engineering methods only protect buildings, not the beaches (e.g: Beach in Galveston was lost in the hurricane in 1900)
• Sea walls fail in Texas, South Carolina, California due to poor maintenance and construction
• Marshfield,Massachusetts and Monmouth Beach, New Jersey = gone
• Rising sea level makes seawall not effective
• People disliked the ugly sceneries

Question 2

Factors leading to a rise in sea level

Answer 2

• Flat topography of the coastal plains (rise of few mm/year can push the ocean a meter in land in Florida)
• North American coast is sinking relative to ocean (e.g NY = 1.5mm/year)
• Extensive coastal development

Question 3

Alternative: Strategic retreat (allow erosion)

Answer 3

Land use management (Engineers stopped challenging nature, now work with natural process)

• The Massachusetts Wetlands Protection Act limits building on coastal land
• Ban sea walls to control erosion on coastal dunes (sea walls prevented the supply of sand to the dunes)
• North Carolina banned hard engineering methods like groyne or rock strong points since the beaches are major assets to the states
• 1986 doubled the distance from sea for large buildings

Question 4

Alternative: Beach replenishment

Answer 4

Atlantic City, Virgina, Miami
Benefit: A compromise b/w building defenses and leave shore to erode
Draw back:
- Cost: 1980 US spent $64m on beach replenishment in Mimi
- Loss of new sand: Erosion removed 30m of sand where sand was extracted to keep the beach stabilised at 60m wide

Question 5

Conclusion

Answer 5

Rising sea level and retreating coasts = continuing issue
Protective hard engineering for major coastal cities like New York (since they’re economically important –> can’t retreat)
Soft engineering in less developed area (Carolina Beach, North Carolina)