Mississippi River Flood History

The record of Mississippi River floods goes back to the earliest explorers: High Flows and Flood History on the Lower Mississippi River Below Red River Landing, LA (1543­ – Present) and the paleoclimate records show megafloods greatly exceeding even the 1927 flood: Brown, P., J. P. Kennett, and B. L. Ingram (1999), Marine evidence for episodic Holocene megafloods in North America and the northern Gulf of Mexico, Paleoceanography, 14(4), 498510, doi:10.1029/1999PA900017; and Tripsanas, E.K. et al., 2013. Paleoenvironmental and paleoclimatic implications of enhanced Holocene discharge from the Mississippi River based on the sedimentology and geochemistry of a deep core (JPC-26) from the Gulf of Mexico. Palaios, 28(9), pp.623–636.

Cape Wind Energy Project

This is a project to develop off-shore wind off Cape Cod. It’s relevance to the Louisiana Coast is that the appeals court ruled that the EIS was incomplete because there was not sufficient geological information about the sea bottom and whether it could support the structures.

Potential Increases in Hurricane Damage in the United States: Implications for the Federal Budget

CBO, Potential Increases in Hurricane Damage in the United States: Implications for the Federal Budget. (2016)

Damage from hurricanes is expected to increase significantly in the coming decades because of the effects of climate change and coastal development. In turn, potential requests for federal relief and recovery efforts will increase as well.

Climate Change and Security in South Asia

GMACCC Publishes “Climate Change & Security In South Asia: Cooperating For Peace”

 CCSinSA_Cover_647x900A GMACCC report published on 31 May 2016 warns that a recent drought in India which has affected over 330 million people – causing displacement and threatening farms –is just the first hint of how climate change could destabilise the South Asian region, unless steps are taken to address the threat posed by a warming, resource-scarce world.

Hurricane Surge on the Louisiana Coast

Hurricane Surge Hazard Primer – Bob Jacobsen (2016)

This Hurricane Surge Hazard Primer summarizes important basic technical information about surge phenomena, hazard, and risk. It provides an overview of surge hazard analysis, including uncertainty in surge hazard estimates. Importantly, this Primer describes the limitations of hurricane surge hazard analysis and risk management under the National Flood Insurance Program. The reader is encouraged to refer to other reports listed in the References for a more detailed explanation of many key concepts.

Lopez, John, Ezra Boyd, Joe Suhayda, Hal Needham, and Kort Hutchison. “The Dynamics of Storm Surge in the Pontchartrain and Maurepas Region.” (2016).

This is a more technical account of the specific issues of surge in the Pontchartrain basin:

Analysis of time-lapse dynamics of recently simulated major storm surges and historical storm surge maximum observations shed new light on spatial and temporal patterns of storm surge within the Lakes Pontchartrain and Maurepas region (PMSC region, see Figure 1). While the terms tilting or sloshing have been previously used to describe key dynamic processes of storm surge movement in Lake Pontchartrain, these terms can be misleading because the peak surge generally rotates around the lake perimeter (“surge rotation”) rather than directly transferring (tilting/sloshing) from one end of the lake to the other.

In this analysis, two recent storms are examined as archetypical events that exemplify a new conceptual model that we introduce. Hurricanes Katrina (2005) and Isaac (2012) had fundamentally different tracks which seem to illustrate well the contrasting patterns of storm surge rotation introduced here. However, while these exemplify a generalized surge rotation model, it is important to keep in mind that our conceptual model is built around local forcing on storm surge and not the larger coastal processes. Every storm is different and the resulting surge is always a result of regional and local forcing. The limitation of this study is that we only discuss the movement of surge within the PMSC region and not the dynamics of surge entering into the PMSC region by more regional meteorological or coastal processes. In spite of this limitation, much can be said about the generalized relative movement of maximum surge in the PMSC region

 

Small Scale River Diversions

The Louisiana Coastal Restoration Plan proposes to build a small number of large river diversions. Another approach is to create small breaks in the levees to allow overflow into wetlands during floods that more closely resembles natural processes. This would be much less disruptive and would not come with the risk of large scale wetlands destruction which has followed all large scale diversions that have been built to this point.

Xu, Y. Jun. “Rethinking the Mississippi River diversion for effective capture of riverine sediments.” Sediment Dynamics from the Summit to the Sea; Xu, YJ, Allison, MA, Bentley, SJ, Collins, AL, Erskine, WD, Golosov, V., Horowitz, AJ, Stone, M., Eds (2014): 463-470.

There have been projects to test these small scale projects. It is not clear that any have built land in the long term.

MR-I Small Sediment Diversions (1996)