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Erosion
| The Mississippi River, high bluffs and Loess
soil are the most significant geologic features of the area. In 1863,
Confederate forces took advantage of the unique topography and constructed twelve miles of
fortifications around the city, of which, four miles was high on the bluffs with eight
emplaced heavy artillery batteries overlooking the Mississippi River. Vicksburg was a
formidable, and imposing fortress city, aptly titled the "Gibralter of the
Confederacy." |
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The Loess (clay) soil in the Vicksburg area
is a fine wind blown sediment which is tighly compacted through water percolation.
When protected by adequate vegetative cover, Loess soil has unique properties
since it can be cut vertically without any need for bank stabilization. During the
Civil War it was perfect for excavating fortifications, trenches, tunnels, approaches, and
parallels, because no shoring was needed. However, when Loess soil lacks
adequate vegetative cover and is left exposed to rain and moving water, it literally
"melts like butter." Exposed areas are prone to severe erosion and can
suffer extreme loss of soil which ultimately threatens roads, bridges, buildings, and
monuments. |
| By 1933, erosion had become such a serious problem that it threatened the very fabric
of the park The Civilian Conservation Corps (CCC) established four camps
within the park to complete a series of erosion
control projects. The enrollees installed concrete drains, gutters and planted
what is now a dense forest for the sole purpose of controlling water runoff and combating
"erosion". |
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Over sixty years later erosion continues to
take a toll. It is still the most ominous threat to long term preservation of historic
vistas and landscapes. The steep bluffs and rugged ravines compound problems as they
create extreme difficulties for personnel and equipment. Direct access is often
limited and hampers efforts to maintain adequate watersheds. |
| Regardless of the quantity and type of erosion control devices utilized,
combatting erosion remains a constant battle with the forces of nature. |
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Last update: Monday, January 22, 2001
http://www.nps.gov/vick/preserve/erosion.htm
Editor: G. Zeman |
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