Responses should be a minimum of 250 words and include direct questions. You may challenge, support or supplement another student’s answer using the terms, concepts and theories from the required readings. Also, do not be afraid to respectfully disagree where you feel appropriate; as this should be part of your analysis process at this academic level.

Respond to:

In researching this week’s forum I chose to look more into the current issue of the approach of Tropical Storm Barry as it approached and began to inundate Louisiana, particularly New Orleans fifteen years after the disaster of Hurricane Katrina in 2005. According to the research there are a number of factors that are combining that are challenging to the resilience of the long and short-term issues to protect the critical infrastructures, as well as the commercial and residential areas of the city of New Orleans and other coastal areas around the country. The increase of mean sea levels, increases in tropical storms by both natural and man-made climate change, and the continued subsidence all contribute to the challenges of conducting effective resilience measures.

In order to build in resiliency from flooding there must be a major restructuring of the existing and new seawalls and levees, and increase in pumping stations allowing for an increase in the Hurricane and Storm Damage Reduction System (HSDRRS). With the increase in subsidence that has been recorded by new technologies, the only way to protect coastal cities from the rising seawaters is through a series of levies, sea walls and artificial tributaries or artificial floodgate systems. There also has to be a realization that without a dramatic turn in reversing global warming, the coastal cities of the United States will continue to lose ground to the oceans.

Even after the restructuring and repairs to the levy systems after Hurricane Katrina, which cost an estimated $14 billion, there is no guarantee of protection against a cataclysmic failure due to all of the different metrics of climate change, ice cap depletion and the rapid subsidence of coastal areas, particularly in the Mississippi Delta area. The U.S. Army Corps of Engineers (USACE) recently completed the renovation of the levee system around New Orleans with an increase in the number and height of the floodwalls. USACE estimates that after almost a dozen years of work and a very large sum of dollars, “the system will stop providing adequate protection in as little as four years because of rising sea levels and shrinking levees” (Frank, 2019).

The amount of mean sea level rise contributed by all of the natural and man-made factors has increased the impacts and occurrences of flooding in our coastal areas that present major challenges to effective resilience efforts in terms of cost and time. The study by Williams and Ismail conclude, “The reality is that it is not economically feasible to protect all coastlines from high rates of sea-level rise and catastrophic super-storms. Structures built for short term (~50 years) and modest sea-level rise (~0.5 m) should be designed such that their height can be raised and size increased in the event that even higher sea levels prevail” (Williams & Ismail, p. 62, 2015).

Due to Hurricane Katrina a series of studies was conducted to represent a Category 5 hurricane and the efforts to reduce the effects through resilient designs of the layers of defense from the rising floodwaters and storm surge. Many types of variables had to be weighed to determine the height of the repaired and new surge barriers, such as the predicted global sea rise, magnitude of storms possible, as well as the continued natural deterioration of the coastal region and subsidence along the coastal areas and Mississippi Delta region. While there is a structuring of a 50-year plan with the plan of addressing land loss and the reconnection of the Mississippi River to the delta area, there is an admissible lack of discussion beyond 2050. Resiliency efforts need to be built around the premise that sea levels will continue to rise, probably more dramatically then originally hypothesized, and buffers such as dunes, seawalls, hardened and elevated structures and a series of plans for relocation, while drastic, will need to be constructed when the cost is no longer feasible.

Mike Simmons

References:

Frank, T. (2019). After a $14-billion upgrade, New Orleans’ levees are sinking. Scientific American. Retrieved from https://www.scientificamerican.com/article/after-a-14-billion-upgrade-new-orleans-levees-are-sinking/

Williams, S. and Ismail, N. (2015). Climate change, coastal vulnerability and the need for adaptation alternatives: planning and design examples from Egypt and the USA. Journal of Marine Science and Engineering. Retrieved from https://www.mdpi.com/books/pdfview/book/559