26 lines
5.5 KiB
Markdown
26 lines
5.5 KiB
Markdown
---
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title: "Beach evolution"
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chunk: 4/5
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source: "https://en.wikipedia.org/wiki/Beach_evolution"
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category: "reference"
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tags: "science, encyclopedia"
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date_saved: "2026-05-05T07:34:26.041541+00:00"
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instance: "kb-cron"
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---
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This Integrated coastal zone management example is based on the "move beach seaward" general planning approach which involves both hard and soft engineering methods. This scenario minimizes the maintenance effort and cost by making optimal use of the coastal geography by incorporating natural coastal geographical features in the engineering design. The cost is kept low by the use of easily available free or cost-effective local material, use of which is already known to or easily acquired by the local workforce. This solution entails beach nourishment (creating recreational area by filling with sand), and further beach expansion and prevention of beach erosion caused by longshore drift and coastal development hazards. The design makes use of a shorter groyne slightly inclined toward the beach in the same direction as downdrift, with a series of "headland groyne" perpendicular to the shore, and a longer "headland groyne" at the end of downdrift side of the beach with smaller "headland groyne" perpendicular to it facing the updrift end of the beach.
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This example of tropical setting, part of the sea could be reclaimed by building a seawall with revetment (slope) fortified with armament of honeycomb seebee made of concrete with hexagonal holes, parts of seawall could be made of gabion. Seawall will sit over gravel or rock. Seawall could be a mix of vertical structures in the areas where more space is needed and tapering revetments (slope) as aesthetic landscaping feature. Revetments could be made of locally available material. Different parts of revetment could have different material and design, such as gabion (welded wire mesh filled with stone, gravel and wood) and honeycomb seebee (made of concrete with hexagonal holes). Honeycomb seebee or gabion could be used in the downdrift areas, though wood groyne would be the cheapest option such as used at Mundesley. Other areas of seawall and revetment could be a mix of cemented low walls, gabion, riprap made of gravel or sand bags. Parts of seawall and revetment could be left exposed especially those made of decorative gabion, and others parts could be covered with low or mid level native plants. Seawall will sit over gravel or rock base which could be wider than the seawall so that it also acts as the riprap armament.
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Reclaimed area could be filled with the sand and stabilized by aesthetic landscaping by growing native trees and plants. A dense layer of native tropical trees could be planted at the mainland side of the reclaimed land with due consideration to the height of the trees that they do not block the view of any construction such as resort or beach house. Reclaimed area would enhance the economical value by creating a sand filled safe recreation area which might house sunbathing areas and inland freshwater or seawater wading pool or lagoon surrounded by bars, restaurants, water sports, etc. Restaurants could have retractable-canopied areas set closer to the seawall greenified with tapering layers of evergreen native tropical plants. Bars could be open air, portable or canopied (thatched roof nipa hut and trellis of native material, pergola or beach parasol) bars with pool and beach seating. Seating could be relaxing-and-sprawling reclined futon type, sunken sand pits, sand filled bean bags on the beach, locally made designer stools/chairs and tables made of native eco-friendly natural material such as bamboo, aged rustic driftwood and abundant low weathering native wood.
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== Status of beaches ==
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=== Historical accretion of beaches ===
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In the Mediterranean Sea, deltas have been continuously growing for the last several thousand years. Six to seven thousand years ago, the sea level stabilized, and continuous river systems, ephemeral torrents, and other factors began this steady accretion. Since intense human use of coastal areas is a relatively recent phenomenon (except in the Nile delta), beach contours were primarily shaped by natural forces until the last centuries.
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In Barcelona, for example, the accretion of the coast was a natural process until the late Middle Ages, when harbor-building increased the rate of accretion.
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The port of Ephesus, one of the great cities of the Ionian Greeks in Asia Minor, was filled with sediment due to accretion from a nearby river; it is now 5 kilometers (3.1 mi) from the sea. Likewise, Ostia, the once-important port near ancient Rome, is now several kilometres inland, the coastline having moved slowly seaward.
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Bruges became a port during the early Middle Ages and was accessible by sea until around 1050. At that time, however, the natural link between Bruges and the sea silted up. In 1134, a storm flood opened a deep channel, the Zwin, linking the city to the sea until the fifteenth century via a canal from the Zwin to Bruges. Bruges had to use a number of outports, such as Damme and Sluis, for this purpose. In 1907, a new seaport was inaugurated in Zeebrugge.
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=== Modern beach recession ===
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At the present time, important segments of low coasts are in recession, losing sand and reducing beach dimensions. This loss can occur very rapidly. There are various reasons for beach recession, some more natural than others (degree of anthropization). Examples of this are occurring at Sète, in California, in Poland, in Aveiro (Portugal), and in the Netherlands and elsewhere along the North Sea. In Europe, coastal erosion is widespread (at least 70%) and distributed very irregularly. |