State of the Beach/State Reports/MS/Beach Erosion
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The Mississippi Office of Geology, Coastal Geology Section within the Mississippi Department of Environmental Quality is actively involved in studying and monitoring coastal change along the Mississippi Gulf Coast. The Coastal Geology Section has numerous sources of data covering a wide variety of coastal monitoring and sampling data types. All of the data are available to the public. Data categories include:
Geographic Information System (GIS) Layers
- GIS layers includes shoreline surveys, historic maps, layers specific to the HGM method of wetland assessment, and Thematic maps.
- The Coastal Data Node can be used to find coastal data from the Coastal Section as well as a data nodes throughout the world.
- Core data and beach profile surveys
- Online GIS mapping using data layers from the Coastal Geology Section
The Coastal Geology Section website also has several presentations, including Coastal Change in Mississippi: A Review of 1850 to 1999 data.
Publications available on the website include Shoreline Erosion Analysis of Grand Bay Marsh and Historical Evolution of Mississippi’s Barrier Islands.
The USGS report National Assessment Of Shoreline Change: Part 1, Historical Shoreline Changes And Associated Coastal Land Loss Along The U.S. Gulf Of Mexico (2004) states:
- "Long-term rates of land loss for Mississippi mainland shores are relatively low. Extensive armoring and periodic beach nourishment around Mississippi Sound have greatly slowed land losses along these shores (Canis and others, 1985). However, the barrier island shores are eroding rapidly. Long-term rates show that 80% of the shoreline has experienced erosion at an average rate of -3.1 ± 1.8 m/yr. Short-term erosion is even more rapid with over 60% of the shoreline eroding at an average rate of -5.8 m/yr. Erosion is most pronounced at the eastern (updrift) ends of the barriers where short-term rates of erosion average -8.3 m/yr and long-term rates average -4.6 ± 1.6 m/yr. The systematic pattern of updrift erosion and downdrift deposition that transfers sand from east to west and promotes westward migration has also reduced the island areas by about one third since the 1850s (Byrnes and others, 1991).
- The most dramatic example of coastal erosion and land loss in Mississippi was the formation and destruction of the Isle of Caprice. This relatively small sand shoal formed in Mississippi Sound between Horn and Ship Islands as a result of barrier migration and changes in current patterns within the adjacent tidal inlet. The Isle of Caprice emerged between 1917 and 1924 when sand deposited between two channels caused several small sand shoals to coalesce (Rucker and Snowden, 1988). In the mid 1920s, during the Prohibition Era, it was developed into an entertainment center with cabanas, a gambling casino, restaurant, artesian potable water supply, electric power plant, and a ferry landing (Rucker and Snowden, 1988). By 1932, all of these assets had been completely destroyed by the Gulf waters and there was no evidence of the Isle of Caprice."
The report Historical Changes in the Mississippi-Alabama Barrier-Island Chain and the Roles of Extreme Storms, Sea Level, and Human Activities by Robert A. Morton of the U.S. Geological Survey (2007) discusses natural and human-caused factors influencing erosion of barrier islands off the coasts of Mississippi and Alabama. Following is the summary from that report:
"An historical analysis of images and documents shows that the Mississippi-Alabama (MS-AL) barrier islands are undergoing rapid land loss and translocation. The barrier island chain formed and grew at a time when there was a surplus of sand in the alongshore sediment transport system, a condition that no longer prevails. The islands, except Cat, display alternating wide and narrow segments. Wide segments generally were products of low rates of inlet migration and spit elongation that resulted in well-defined ridges and swales formed by wave refraction along the inlet margins. In contrast, rapid rates of inlet migration and spit elongation under conditions of surplus sand produced low, narrow, straight barrier segments.
Since the mid 1800s, average rates of land loss for all the MS islands accelerated systematically while maintaining consistency from island to island. In contrast, Dauphin Island, off the Alabama coast, gained land during the early 20th century and then began to lose land at rates comparable to those of the MS barriers. There is an inverse relationship between island size and percentage of land reduction for each barrier such that Horn Island lost 24% and Ship Island lost 64% of its area since the mid 1800s. Ship Island is particularly vulnerable to storm-driven land losses because topographic and bathymetric boundary conditions focus wave energy onto the island. The three predominant morphodynamic processes associated with land loss are: (1) unequal lateral transfer of sand related to greater updrift erosion compared to downdrift deposition, (2) barrier narrowing resulting from simultaneous erosion of the Gulf and Sound-side shores, and (3) barrier segmentation related to storm breaching. The western three fourths of Dauphin Island are migrating landward as a result of storms that erode the Gulf shore, overwash the island, and deposit sand in Mississippi Sound. Petit Bois, Horn, and Ship Islands have migrated westward as a result of predominant westward sediment transport by alongshore currents, and Cat Island is being reshaped as it adjusts to post-formation changes in wave and current patterns associated with deposition of the St. Bernard lobe of the Mississippi delta.
The principal causes of barrier island land loss are frequent intense storms, a relative rise in sea level, and a deficit in the sediment budget. The only factor that has a historical trend that coincides with the progressive increase in rates of land loss is the progressive reduction in sand supply associated with nearly simultaneous deepening of channels dredged across the outer bars of the three tidal inlets maintained for deep-draft shipping. Neither rates of relative sea level rise nor storm parameters have long-term historical trends that match the increased rates of land loss since the mid 1800s. The historical rates of relative sea level rise in the northern Gulf of Mexico have been relatively constant and storm frequencies and intensities occur in multidecadal cycles. However, the most recent land loss accelerations are likely related to the increased storm activity since 1995.
Considering the predicted trends for storms and sea level related to global warming, it is clear that the barrier islands will continue to lose land area at a rapid rate without a reversal in trend of at least one of the causal factors. The reduction in sand supply related to disruption of the alongshore sediment transport system is the only factor contributing to land loss that can be managed directly. This can be accomplished by placing dredged material so that the adjacent barrier island shores receive it for island nourishment and rebuilding."
The U.S. Geological Survey (USGS) Coastal and Marine Geology Program has several data products and reports that provide beach erosion data for the Mississippi coast and for adjacent Gulf of Mexico states. This includes information and data from the National Assessment of Shoreline Change Project. Numerous additional documents can be found on the Coastal and Marine Geology Program website by using their "Online Science Resource Locator" to search under "beaches" or "erosion" for the Gulf of Mexico region.
The Mississippi Geospatial Clearinghouse (MGC) provides access to a comprehensive spatial information warehouse of Geographic Information Systems (GIS) resources of Mississippi for use by government, academia, and the private sector. The goal of the MGC is to make the application of spatial information technologies within the State of Mississippi more efficient by reducing the duplication of spatial data production and enhancing distribution through effective cooperation, standardization, communication, and coordination. By visiting the MGC you can view and obtain GIS data, maps and information.
The Hurricanes of 2005 created unprecedented destruction within the Gulf Region of the United States of America. Beginning with Hurricane Cindy on July 6th 2005, which made landfall near Waveland, Mississippi, peaking with Hurricane Katrina, which made landfall on the 29th of August on the Louisiana-Mississippi border, and ending with Hurricane Rita on the 24th of September, which also caused additional damage to the coastline of Mississippi, this series of tremendous storms caused unparalleled devastation to homes and businesses, industry, livelihoods, regional economies, environmental resources, and most importantly, dealt a life-changing blow to the people that call this region home. Coastal Mississippi was the point of impact of the greatest tidal surge that has hit the mainland of the United States in its recorded history. Hurricane Katrina caused almost complete destruction of several large coastal communities, and seriously damaged numerous others. The destruction was on a scale unmatched by any natural disaster in U.S. history.
The Heinz Center's Evaluation of Erosion Hazards, conducted for the Federal Emergency Management Agency (FEMA), studied the causes of coastal erosion hazards and proposed a variety of national and regional responses. The study, published in April 2000, concentrates on the economic impacts of erosion response policies as well as the cost of erosion itself to homeowners, businesses, and governmental entities.
A NOAA website that has graphs of sea level data for many coastal locations around the country over the last 40 to 50 years and projections into the future is Sea Levels Online.
NOAA Shoreline Website is a comprehensive guide to national shoreline data and terms and is the first site to allow vector shoreline data from NOAA and other federal agencies to be conveniently accessed and compared in one place. Supporting context is also included via frequently asked questions, common uses of shoreline data, shoreline terms, and references. Many NOAA branches and offices have a stake in developing shoreline data, but this is the first-ever NOAA Website to provide access to all NOAA shorelines, plus data from other federal agencies. The site is a culmination of efforts of NOAA and several offices within NOS (including NOAA’s Coastal Services Center, National Geodetic Survey, Office of Coast Survey, Special Projects Office, and Office of Ocean and Coastal Resource Management) and other federal agencies to provide coastal resource managers with accurate and useful shoreline data.
A related site launched in 2008 is NOAA Coastal Services Center's Digital Coast, which can be used to address timely coastal issues, including land use, coastal conservation, hazards, marine spatial planning, and climate change. One of the goals behind the creation of the Digital Coast was to unify groups that might not otherwise work together. This partnership network is building not only a website, but also a strong collaboration of coastal professionals intent on addressing coastal resource management needs. Website content is provided by numerous organizations, but all must meet the site’s quality and applicability standards. More recently, NOAA Coastal Services Center has developed a Sea Level Rise and Coastal Flooding Impacts Viewer as part of its Digital Coast website. Being able to visualize potential impacts from sea level rise is a powerful teaching and planning tool, and the Sea Level Rise Viewer brings this capability to coastal communities. A slider bar is used to show how various levels of sea level rise will impact coastal communities. Completed areas include Mississippi, Alabama, Texas, Florida, and Georgia, with additional coastal counties to be added in the near future. Visuals and the accompanying data and information cover sea level rise inundation, uncertainty, flood frequency, marsh impacts, and socioeconomics.
Erosion Contact Info
Coastal Geology Section
Mississippi Office of Geology
PO Box 20307
Jackson, MS 39289
Hazard Avoidance Policies/Erosion Response
See the Erosion Response section.
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