scholarly journals MODELING THE EFFECT OF LAND-BUILDING PROJECTS ON STORM SURGE AND HURRICANE WAVES IN COASTAL LOUISIANA

2018 ◽  
pp. 21
Author(s):  
Kelin Hu ◽  
Qin Chen ◽  
Ehab Meselhe
Keyword(s):  
Storm Surge ◽  
Mississippi River ◽  
Coastal Wetlands ◽  
Wetland Loss ◽  
High Rate ◽  
Coastal Protection ◽  
Building Projects ◽  
Lower Mississippi River ◽  
Louisiana Coast ◽  
Coastal Louisiana

Wetland loss on the hurricane-prone Louisiana coast continues at an alarmingly high rate. Coastal Louisiana is at risk of losing between 2118 and 4677 km2 of land over the next 50 years (Couvillion et al., 2013). To combat the devastating wetland loss, the Louisiana 2017 Coastal Master Plan (CMP) called for sediment diversions along the lower Mississippi River to enhance sediment supplies to coastal wetlands and build more wetlands. The Louisiana Coastal Protection and Restoration Authority (CPRA) plans to spend $2 billion on the Mid-Breton and Mid-Barataria sediment diversion projects. In this study, numerical experiments were conducted to quantify the effect of land-building projects on storm surge and hurricane waves in Barataria and Breton Basins of Louisiana.

scholarly journals ASSESSMENT OF THE EVOLUTION OF STORM SURGE IN COASTAL LOUISIANA

2018 ◽  
pp. 42
Author(s):  
Christopher Siverd ◽  
Scott Hagen ◽  
Matthew Bilskie ◽  
DeWitt Braud ◽  
Shu Gao ◽  
...  
Keyword(s):  
Storm Surge ◽  
Coastal Wetlands ◽  
Oil And Gas ◽  
Water Levels ◽  
Coastal Protection ◽  
Coastal Landscape ◽  
Hurricane Storm Surge ◽  
The Pearl River ◽  
Louisiana Coast ◽  
Sabine Lake

The Louisiana coastal landscape comprises an intricate system of fragmented wetlands, natural ridges, man-made navigation canals, flood protection and oil and gas infrastructure. Louisiana lost approximately 1,883 square miles (4,877 sq km) of coastal wetlands from 1932 to 2010 including 300 square miles (777 sq km) lost between 2004 and 2008 due to Hurricanes Katrina, Rita, Gustav and Ike (Couvillion et al., 2011). A projected additional 2,250 square miles (5,827 sq km) of coastal wetlands will be lost over the next 50 years if no preventative actions are taken (Coastal Protection and Restoration Authority of Louisiana, 2017). Storm surge models representing historical eras of the Louisiana coastal landscape can be developed to investigate the response of hurricane storm surge (e.g. peak water levels, inundation volume and time) to land loss and vegetative changes. Land:Water (L:W) isopleths (Gagliano et al., 1970; Twilley et al., 2016; Siverd et al., 2018) have been calculated along the Louisiana coast from Sabine Lake to the Pearl River. These isopleths were utilized to develop a simplified coastal landscape (bathymetry, topography, bottom roughness) representing circa2010. Similar methods are employed with the objective of developing storm surge models that represent the coastal landscape for past eras (circa1890, c.1930, c.1970).

scholarly journals The “Problem” of New Orleans and Diminishing Sustainability of Mississippi River Management—Future Options

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 813
Author(s):  
John W. Day ◽  
Rachael Hunter ◽  
G. Paul Kemp ◽  
Matthew Moerschbaecher ◽  
Christopher G. Brantley
Keyword(s):  
New Orleans ◽  
Mississippi River ◽  
Coastal Wetlands ◽  
High Water ◽  
City Management ◽  
The Future ◽  
Lower Mississippi River ◽  
Coastal Louisiana ◽  
The City ◽  
Precipitation Events

Climate change forcings are having significant impacts in coastal Louisiana today and increasingly affect the future of New Orleans, a deltaic city mostly below sea level, which depends on levee and pumps to protect from a host of water-related threats. Precipitation has increased in the Mississippi River basin generally, increasing runoff, so that in recent years the Mississippi River has been above flood stage for longer periods of time both earlier and later in the year, increasing the likelihood that hurricane surge, traditionally confined to summer and fall, may compound effects of prolonged high water on river levees. The Bonnet Carré Spillway, just upstream of New Orleans has been operated more often and for longer periods of time in recent years than ever before in its nearly 100-year history. Because all rain that falls within the city must be pumped out, residents have been exposed to interior flooding more frequently as high-intensity precipitation events can occur in any season. A sustainable path for New Orleans should involve elevating people and sensitive infrastructure above flood levels, raising some land levels, and creating water storage areas within the city. Management of the lower Mississippi River in the future must include consideration that the river will exceed its design capacity on a regular basis. The river must also be used to restore coastal wetlands through the use of diversions, which will also relieve pressure on levees.

Simulating Hurricane Storm Surge in the Lower Mississippi River under Varying Flow Conditions

2013 ◽  
Vol 139 (5) ◽  
pp. 492-501 ◽  
Author(s):  
R. C. Martyr ◽  
J. C. Dietrich ◽  
J. J. Westerink ◽  
P. C. Kerr ◽  
C. Dawson ◽  
...  
Keyword(s):  
Storm Surge ◽  
Mississippi River ◽  
Flow Conditions ◽  
Lower Mississippi River ◽  
Hurricane Storm Surge

scholarly journals Life Cycle of Oil and Gas Fields in the Mississippi River Delta: A Review

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1492
Author(s):  
John Day ◽  
H. Clark ◽  
Chandong Chang ◽  
Rachael Hunter ◽  
Charles Norman
Keyword(s):  
Pore Pressure ◽  
Mississippi River ◽  
Coastal Wetlands ◽  
Oil And Gas ◽  
Produced Water ◽  
Wetland Loss ◽  
Second Phase ◽  
Surface Hydrology ◽  
Spilled Oil ◽  
Spoil Banks

Oil and gas (O&G) activity has been pervasive in the Mississippi River Delta (MRD). Here we review the life cycle of O&G fields in the MRD focusing on the production history and resulting environmental impacts and show how cumulative impacts affect coastal ecosystems. Individual fields can last 40–60 years and most wells are in the final stages of production. Production increased rapidly reaching a peak around 1970 and then declined. Produced water lagged O&G and was generally higher during declining O&G production, making up about 70% of total liquids. Much of the wetland loss in the delta is associated with O&G activities. These have contributed in three major ways to wetland loss including alteration of surface hydrology, induced subsidence due to fluids removal and fault activation, and toxic stress due to spilled oil and produced water. Changes in surface hydrology are related to canal dredging and spoil placement. As canal density increases, the density of natural channels decreases. Interconnected canal networks often lead to saltwater intrusion. Spoil banks block natural overland flow affecting exchange of water, sediments, chemicals, and organisms. Lower wetland productivity and reduced sediment input leads to enhanced surficial subsidence. Spoil banks are not permanent but subside and compact over time and many spoil banks no longer have subaerial expression. Fluid withdrawal from O&G formations leads to induced subsidence and fault activation. Formation pore pressure decreases, which lowers the lateral confining stress acting in the formation due to poroelastic coupling between pore pressure and stress. This promotes normal faulting in an extensional geological environment like the MRD, which causes surface subsidence in the vicinity of the faults. Induced reservoir compaction results in a reduction of reservoir thickness. Induced subsidence occurs in two phases especially when production rate is high. The first phase is compaction of the reservoir itself while the second phase is caused by a slow drainage of pore pressure in bounding shales that induces time-delayed subsidence associated with shale compaction. This second phase can continue for decades, even after most O&G has been produced, resulting in subsidence over much of an oil field that can be greater than surface subsidence due to altered hydrology. Produced water is water brought to the surface during O&G extraction and an estimated 2 million barrels per day were discharged into Louisiana coastal wetlands and waters from nearly 700 sites. This water is a mixture of either liquid or gaseous hydrocarbons, high salinity (up to 300 ppt) water, dissolved and suspended solids such as sand or silt, and injected fluids and additives associated with exploration and production activities and it is toxic to many estuarine organisms including vegetation and fauna. Spilled oil has lethal and sub-lethal effects on a wide range of estuarine organisms. The cumulative effect of alterations in surface hydrology, induced subsidence, and toxins interact such that overall impacts are enhanced. Restoration of coastal wetlands degraded by O&G activities should be informed by these impacts.

scholarly journals Field-based Estimate of the Sediment Deficit in Coastal Louisiana

2019 ◽  
Author(s):  
Kelly Marie Sanks ◽  
John B Shaw ◽  
Kusum Naithani
Keyword(s):  
Coastal Wetlands ◽  
Unit Area ◽  
Field Measurements ◽  
Trapping Efficiency ◽  
Organic Mass ◽  
Rise Rate ◽  
Sediment Mass ◽  
Riverine Sediment ◽  
Louisiana Coast ◽  
Coastal Louisiana

Coastal and deltaic sediment balances are crucial for a region’s sustainability. However, such balances remain difficult to quantify accurately, particularly for large regions. We calculate organic and mineral sediment mass and volume balances using field measurements from 273 Coastwide Reference Monitoring System sites across the Louisiana coast between 2006 and 2015. The rapid relative sea level rise rate (average 13.4 mm/yr) is offset by the small dry bulk densities observed (average 0.3 g/cm3) to produce a 16.2 ± 41.1% mass deficit and 24.1 ± 14.0% volume deficit, significantly smaller than recent predictions for 2000 – 2100 (73 to 79% mass deficit). Geostatisical estimates show that this deficit is primarily located in areas not directly nourished by major rivers, yet these regions still accumulate ~24 MT/yr of mineral sediment. A fluvial sediment discharge of 113.8 MT/yr suggests a coast-wide trapping efficiency of 31.5 ± 15.8% of the riverine sediment, excluding subaqueous deposition. Organic accumulation accounts for 30% of all volume accumulation during our study period and total organic mass accumulation per unit area is relatively constant in both directly and indirectly nourished regions. Sediment characteristics in the modern coastal wetlands differ from the Holocene deposit, suggesting secular changes within the system that will likely continue to influence coastal dynamics over the coming decades. Our results suggest that the gap between accommodation and accumulation (mass or volume) during this decade was not as large as the previously predicted century average.

scholarly journals A Synthesis of Deepwater Horizon Impacts on Coastal and Nearshore Living Marine Resources

2021 ◽  
Vol 7 ◽  
Author(s):  
Steven A. Murawski ◽  
Joshua P. Kilborn ◽  
Adriana C. Bejarano ◽  
David Chagaris ◽  
David Donaldson ◽  
...  
Keyword(s):  
Oil Spill ◽  
Mississippi River ◽  
Deepwater Horizon ◽  
Community Change ◽  
Series Data ◽  
Trawl Survey ◽  
Barataria Bay ◽  
Lower Mississippi River ◽  
Coastal Louisiana

The 2010 Deepwater Horizon (DWH) oil blowout in the Gulf of Mexico began on April 20, originating in the deep sea 66 km off the Louisiana coast. By early June, DWH oil had spread to coastal Louisiana, Mississippi, Alabama and western Florida. An estimated 2,113 km of shoreline were oiled, making DWH the largest marine oil spill in global history by length of affected shoreline. Additionally, a series of oil spill response measures were deployed, including diversions of Mississippi River discharge to forestall oil coming ashore, and the establishment of large-scale fishery closures, with both affecting coastal resources to varying degrees. Here, we review published studies and describe additional analyses evaluating long-term impacts of DWH on coastal/nearshore biological resources. We assembled time-series data collected by state, federal and academic partners on population abundance and environmental conditions to evaluate species and community change. Our study focused on plankton, invertebrates, fishes and dolphins, and 13 “key species” were selected to conduct semi-quantitative vulnerability-resilience (V-R) analyses. At one extreme, early life stages of Gulf Menhaden (Brevoortia patronus) were not affected due to seasonal spawning and larval development preceding the spill. In contrast, demographically independent populations of the common Bottlenose Dolphin, (Tursiops truncatus) suffered a variety of severe and ongoing health effects owing to oil exposure. Virtually all of the heavily oiled salt marsh habitat was in Louisiana, with the majority occurring in Barataria Bay. Multispecies trawl survey abundances declined post-DWH throughout eastern coastal Louisiana but remained stable elsewhere. A regime shift in composition of Barataria Bay trawl survey catches occurred during and following the spill, the persistence of which was associated with long-term reductions in average salinity and increases in water clarity. In some cases, fishery closures were associated with measurable but ephemeral increases in abundance of some targeted and bycatch species. Freshwater flooding of marshes was ineffective in preventing coastal oiling and severely affected benthic euryhaline resources including Eastern Oyster (Crassostrea virginica) and Marsh Periwinkle (Littoraria irrorata). The flooding response measure experiment also indicates the directionality of impacts that further planned water diversions may have on ecological communities of lower Mississippi River basins.

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