Despite efforts to fortify its beaches and swamps, part of Barataria Bay is slowly leaving.
Located on the Mississippi River, between Bayu LaFurche and Mississippi, Lake Barataria in Louisiana is a shrinking network of swamps, marshes, and islands. Several other beaches in the Mississippi River Delta or elsewhere in the United States have changed in recent decades. It is estimated that between 1932 and 2016, the Gulf lost 430 square miles (1,120 square kilometers) of land, about the size of Los Angeles.
Many natural և processes initiated by humans are responsible. One of the most important is the natural settling and condensation of geologically young mud, which is located in the bay and its surroundings. The Plaquemines Delta (east side of the Gulf of Barataria) is being built as a result of the current outflow from the Mississippi River. Only 400 years ago, the river stopped delivering large amounts of sediment to the Lafores Delta (west side of the Gulf), which means that landings in both areas are fairly rapid.
The construction of a flood canal system to limit flooding has also played a large role in land loss, preventing water from seeping into the bay and starving new sediment. Prior to the levels, sedimentation used to add nearly 10,000 square miles (4,000 square miles) of land per year to the Mississippi Delta, an area larger than Vermont. Today, one of several parts of the Louisiana coast that is still building new land is in the Achafalaya River Delta. Unlike Barataria Bay, it receives minimal freshwater sediment and does not build any new soil.
The dual challenges of global warming and rising sea levels have contributed to change. Melting ice at the poles ջերմ Thermal expansion of the ocean (through warming) has accelerated land loss rates in the Barataria Sea by about 20-30%, said Guangdong Li, a geologist at Tulane University who recently published a study on sediment dynamics in the Barataria Sea. ,
This pair of images highlights the magnitude of the change in the Barataria Sea. Landsat 8 Land Imager (OLI) captured the first photo on October 2, 2020; Landsat 5 Thematic Cartographer acquired the second image on August 31, 1985. Both were swept away by the tide. Color differences are due to fluctuations in illumination and the amount of sediment suspended in the water.
The images depict the widespread loss of land, depicting human efforts to fortify beaches and swamps, despite the encroachment of the seas. After the devastation caused by Hurricanes Katrina Rita in 2005 De After the Deepwater Horizon oil spill in 2010, Louisiana pursued a comprehensive coastal protection և rehabilitation program aimed at strengthening all the dam islands in New Orleans. with hope. – Damaged swamps նել to minimize the damage of future storms.
“The prevailing winds in coastal Louisiana are southeast, and Lake Barataria is starving,” said Chris Siverd, a coastal engineer and Louisiana State University graduate who surveyed the area. “If they are not rebuilt continuously, the barrier islands will migrate north-west and narrow.”
One of the most visible projections of these images involves the restoration of the Kaminada Headlands, a largely undeveloped barrier island in the southwestern Gulf. The Beach Nutrition Project, the second largest in Louisiana history, expanded and restored 13 miles (21 kilometers) of beach.
Queen Bess Island is another area where new land is visible. In 2019, offshore engineers used oil spill remedies to rebuild the small island, which is the main nest for brown pelicans. Biologists expect the renovated island to provide habitat for tens of thousands of peacock nests. A similar project completed in 2012 rebuilt the ailing Pelican Island in the eastern part of the sea.
Recently, coastal engineers are working on a new project that strengthens and expands the rapidly collapsing barrier island, which was once the basis for the famous French pirates, slave traders, and Jean-Lafitte, the hero of the Battle of New Orleans.
There has been positive news for Barataria Bay. The main efforts to divert water and sediment from the main Mississippi Canal to the Gulf are under construction. At the same time, studies show that the rate of land loss է landing has slowed in recent years. After losing 10 square miles (25 square kilometers) a year in the early 1980s, the loss in recent years has averaged less than 2 square kilometers (5 square kilometers). The decline is likely due to the cessation of the number of harmful storms, a possible reduction in the natural rate of landing, and a decline in the impact of oil extraction, say researchers in the US Geological Survey.
“But in the long run, significant drowning of Barataria Bay և the entire Mississippi River Delta is inevitable,” Lee said. “Even if the sedimentary loads were restored before the construction of the dam at the level of the first part of the 20th century, the numbers still do not add up. “The delta was still losing ground due to the accelerating rate of sea level rise.”
NASA Images of the Earth Observatory by Lauren Dauphin using data from the US Geological Survey.