photo by Jocelyn Augustino/FEMA News Photo
Can restored wetlands protect New Orleans?
Storm Surge Buffering
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Data shows that the major flooding experienced during hurricane Katrina was a result of waves “overtopping” floodwalls and levees, and from breaches in the levee/wall systems surrounding the city (Ebersol et al, 2010; Link, 2010). Plans to deepen the support for flood walls has already been proposed by the Army Corp of Engineers as a way to prevent flood wall failure. It is our suggestion that incorporating additional earthen barriers with vegetation and tree-root systems in place, such as chinampas, could increase the integrity of this system, and possibly prevent such failures from happening again. Vegetational root systems have been shown to increase the durability of wetlands and shorelines by preventing alluvium erosion, and the plants themselves shown to dampen incoming waves by dissipating wave energy (Dean, 1978; Augusin et al., 2009). The benefit of plant growth is two fold: First, the continual slowing of wave action within wetlands encourages sediment deposition, which will help build the wetlands over time. Second, land mass and vegetation function together to decrease wave attenuation during storm events. Fundamentally, chinampas could be used to expand the storm surge buffer protecting New Orleans. |
Freshwater Chinampas |
Freshwater, agricultural chinampas act as a barrier during a storm. While it is true that the freshwater chinampas might be swamped by seawater during storm events, and the crops temporarily destroyed, we think this is a small detraction from the protection they could provide during such events. Once the sea water retracted, the chinampas would return to their original freshwater composition and be replanted. |
Brackish Water Chinampas |
Replanted with native plant and tree species, these chinampas have great potential to decrease wave attenuation and water speeds during storms. In this way, they will contribute to reducing the overtopping and failure events that happened along the levees, dikes and flood walls during past hurricane events.
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Michelle Packer
Site maintained by Michelle Packer
Contact email: [email protected]
Sustainability and Collapse: Can the Past Inform the Future?
University of Texas, Arlington
2013
Site maintained by Michelle Packer
Contact email: [email protected]
Sustainability and Collapse: Can the Past Inform the Future?
University of Texas, Arlington
2013