Subsidence In New Orleans Essay

Numerous different aspects were altered due to the ruckus of Hurricane Katrina. The first major aspect was housing and location. Katrina nearly demolished 300,000 homes. The ascending sea level along the coast resulting from onshore winds is a storm surge. With a twenty-two foot storm surge in New Orleans and a twenty-seven foot storm surge in Mississippi, Hurricane Katrina averaged a shocking twelve foot storm surge. As a storm surge’s footage increases, the surge will continue to move inland farther and farther. Hurricane Katrina’s storm surge is documented as moving inland a total of twelve miles into the state of Mississippi (FAQS, 2013). Hurricane Katrina impacted a total of seven states. Five of these states were Georgia, Florida, Alabama, Mississippi, and Louisiana. Kentucky and Ohio were two more states affected but in a different way. Because of the tremendous amount of water, Kentucky and Ohio were victims of the Mississippi River flooding. Some states experienced more extreme destruction than others. Alabama, Mississippi, and Louisiana experienced Hurricane Katrina’s wrath firsthand. These three southern states were affected the worst by the massive storm (FAQS, 2013). Mississippi’s forest industry experienced a great amount of destruction losing 1.3 million acres of valuable forest land. The main cause of destruction in New Orleans was blamed on the failure of the levee system to stand its ground

“There are natural hazards, but disasters are the result of human actions that put people and property in harm’s way” (Cigler 2007: 64). Throughout history New Orleans has been continuously altered by the presence of humans through the creation of levees and canals, the introduction of artificial irrigation systems, and through human induced processes that have ultimately accelerated the process of land degradation and erosion. While a natural hazard struck New Orleans in 2005, the disaster portion resulting from Hurricane Katrina was a result of human induced interactions throughout the history of New Orleans.

New Orleans was originally founded on high ground overlooking the Mississippi River, above sea level. Also surrounded by Lake Pontchartrain and Lake Borgne, New Orleans was susceptible to hurricanes that would come up the coast into the Gulf. Originally New Orleans was naturally protected by “coastal swamps that helped absorb the energy of storm surges before they reached dry land.” (Stillman 228) At this point Americans were more concerned with the floods that happened annually from the Mississippi River. In the early days, settlers built a mile long levee to block overflows from the mighty Mississippi while landowners constructed their own levees.

When this occurs, water from the wetland buildup can seep into the ground and be stored as ground for aquifers.

This total erosion is a result of a number of factors caused by both natural and human activity.1

Hurricane Katrina hit the southern coast of the United States on August 28, 2005. The center of Hurricane Katrina struck New Orleans on the morning of August 29, 2005. The devastating effect of this hurricane resulted in more than 1,800 citizens losing their lives, as well as more than an estimated $81 billion dollars in damages occurred. By August 31, 2005, eighty-percent of the city became submerged under water because the storm surge breached the city's levees at multiple points. If the levees are damaged massive water will flood Louisiana from the Gulf Coast, the Mississippi River, and other surrounding bodies of water. Some areas of New Orleans were 15 feet under water. Winds of Hurricane Katrina reached an astounding category 3 as

The reason why the Delta wetlands is larger than twenty years ago is because of deposition. It takes all of the dirt and sediments underneath the river and deposits all of the sediments and dirt into the marsh bigger and expanding the delta wetlands that’s why the soil is so soft and mushy is because there is a lot of water in the soil.

Associated activities may include installing drainage systems, grading slopes, ditching for storm drainages, and conduits for service utilities. The disturbance of natural patterns of runoff and rainwater infiltration through modified drainage can lead to the concentration of water flow at sites that previously only took direct rainwater infiltration; this can result in rapid forming cover-subsidence sinkholes (Waltham et al, 2005, p. 159). The many impervious surfaces used in modified drainage activities also impedes groundwater recharge, which can consequently lower the water

Erosion- Soil and rock is moved from one area to another by water, ice, wind, or gravity

The city of New Orleans is the most populated city in state of Louisiana. Due to the geographical location, the city was at a significant risk for flooding. New Orleans was originally settled on the natural levees, along the Mississippi River. The Flood Control Act of 1965, authorized the United States Army Corps of Engineers to design and construct numerous flood control projects including the Lake Pontchartrain and Vicinity, Louisiana Hurricane Protection Project in the New Orleans region of south Louisiana ([PUBLIC LAW 89-298-OCT. 27, 19). Following the implementation of the act, the US Army Corps of Engineers built floodwalls and man-made levees to provide security against flooding. In the subsequent aftermath of Katrina, studies have shown that the levees were improperly built and flood water levels estimates were inaccurate during the initial planning phases and development. As a result, when Hurricane Katrina made landfall on August, 29 2005 the storm caused a breach in the levees which resulted in 80% of the city flooding. Over 20 feet of water covered certain parts of the city and New Orleans was declared a disaster area that required extensive recovery operations. operations.

Finally, because many residents do not return, the city is not able to rebuild many of its neighborhoods. One of the main reasons was because of the serious destruction after the storm. As the majority of the city was sitting below sea level, 80 percent of the land area was drowned by the disastrous floodwaters because of numerous of the levee failures. In New Orleans, “more than 70 percent of

On August 29, 2005, Hurricane Katrina struck the Gulf Coast of the United States. It had a category 3 rating on hurricane scale with sustained winds of 100-140 miles per hour and lasted for days. The storm did a great deal of damage, but its aftermath was catastrophic. “Hundreds of thousands of people in Louisiana, Mississippi and Alabama were displaced from their homes, and experts estimate that Katrina caused more than $100 billion in damage.” (Hurricane Katrina, 2009). Further, though Katrina Hurricane affected the Gulf Coast area, the city of New Orleans was particularly the most at risk and affected, since half of the city actually lies above sea level. In the past, the Army Corp of Engineers had built a system of levees and seawalls to keep water entering from the Mississippi River, Lake Pontchartrain, and Lake Borgene to the city; however, with Hurricane Katrina striking the city, it was impossible to prevent flooding. When the storm surging New Orleans, it damaged many of the city’s levees and seawalls, eventually nearly 80 percent of the city was flooded and around 90 percent of the city’s population had to be evacuated; additionally, “many were displaced from their homes and experts estimate that Katrina caused more than $100 billion in damage.” (Hurricane Katrina, 2009)

erosion the response is a decrease in the mean elevation of about 0.17km. Tectonics may

Gully erosion happens when runoff concentrates and flows strongly enough to detach and move soil particles. For example, a waterfall may form, with runoff picking up energy as it plunges over the gully head. Gullies may develop in watercourses or other places where runoff concentrates. This type of erosion is highly visible and affects soil productivity, restricts land use, and can damage roads, fences and buildings. The depth of the gully developed can range from 2m up to 15 m.

The wastewater reclamation can also be classified based on the constructed wetlands used for their treatment. Constructed wetlands can be divided into two major groups, namely surface flow or sub-surface flow. The latter can be further sub-divided into vertical or horizontal flow. There are many more types of wetlands available but the ones above are the main ones currently in use.