Essay, Pages 3 (712 words)
Nature is not static, thus it would make sense that coastlines, too, would be in constant fluxuation. For millions of years the morphology of Nova Scotian , as well as global, coastlines have been changing. Beaches are a fine balance between accretion and depletion of sediments but go through cycles of creation and destruction (Taylor).
Dunes, the accrual of beach sediment, act as a barrier against storm surges and as a habitat for coastal species, including many types of dune grass, birds and insects.
Generally the dunes in Nova Scotia are moving landward (Taylor).
However, it is when costal erosion interferes with human development, that it becomes a problem. Humans have the ability to protect the forty-five dunes, over a kilometer in length in many different manners (Hale), including hard and soft defenses or leaving an area to the course of nature.
Of the wide variety of hard defenses, groynes are arguably the most effective at creating dunes.
While deposition generally equals erosion on the leeside, a properly placed groyne can be extremely successful. Waterside, Pictou County, has the fastest growing dune system in Nova Scotia, due to a groyne. The groyne is ideally placed, with the leeside as the entrance to the local harbor.
This means that the eddies from the groyne help to keep the harbor mouth clean.
Vehicular barriers, usually a large fence of boulders, metal, wood or a combination, are effective at protecting dunes. Many of the larger beaches in Nova Scotia, but particularly Lighthouse Beach has had problems with ATVs and ORVs.
They have caused damage to dune grass where erosion takes place faster than normal.
Another effective hard defense is a fence. This can be simple, in that it need only be wooden slats. The idea behind a fence is that it will keep humans and animals, which would potentially destroy the dune, off.
An example of such a destroyed dune is one in Waterside. The boardwalk protected the rear dunes, so they flourished, but the boardwalk ended on the crest of the foredune, and caused erosion from repeated trampling. . Alternatively, at Melmerby Beach, also in Pictou County, the boardwalk has protected the dunes completely. The dune grass is healthy for the entirety of the back dunes, and there is no erosion ridge on the foredune.
On the other hand, a fence could be so simple as a rope with a sign posted. This could be a Temporary Closure due to Piping Plover nesting grounds, as seen on Melmerby Beach.
The most natural defense is just the posting of a sign dictating to stay off of the dunes. This is a strategy generally combined with another to provide a stronger defense against those damaging them.
Soft defenses, such as artificially planting dune grass, can be more aesthetic than hard defenses if planted properly. The sprigs were planted at Lighthouse Beach to prevent the wind from scouring the top of the dune. The sprigs were planted in sections, as Baird and Associates were testing dune grass for dependability vigor in the specific conditions of the spit.
Bard and Associates also introduced beach nutrification, in the form of cobble. They initially did extensive work to repair a breach that had formed in the middle of Lighthouse Beach, by laying armor stone in a pyramidal pattern. After cobble nutrification, which was used to protect the leeside of a groyne, there has been a return of more sand .
Each management strategy against erosion has both benefits and drawbacks. In general, natural defenses are not for combating erosion, rather protecting against it in the first place. Hard defenses are used to stop or reverse erosion, but do not tend to be aesthetically pleasing. Natural-looking soft defenses are also semi-strong. They can withstand more than natural dunes can but tend to be costly in repair and maintenance.
Humans influence dunes both positively and negatively. For each positive solution, there was something negative initially, for it to be put in place. We must also remember that we are the only ones who sculpt the earth, no other species tries. There have nearly always been beaches, and the coastlines have continuously been in constant fluxuation. Thus we need to weigh the pros and the cons of letting nature take its course (Taylor).
Cite this essay
Dune Evaluation. (2020, Jun 02). Retrieved from https://studymoose.com/dune-evaluation-new-essay