Claustrum: A Sea Wall Between the Island and the Shell?

2021 ◽  
pp. 23-25
Author(s):  
Régis Olry ◽  
Duane E. Haines
Keyword(s):  
2020 ◽  
Vol 24 (1) ◽  
pp. 100-105
Author(s):  
Herawati Herawati ◽  
Muhammad Arsyad Thaha ◽  
Chairul Paotonan

Abstrak Wilayah pesisir merupakan pertemuan antara wilayah laut dan wilayah darat, dimana daerah ini merupakan daerah interaksi antara ekosistem darat dan ekosistem laut yang sangat dinamis dan saling mempengaruhi. Tujuan penelitian ini adalah untuk menentukan material lokal yang potensial dapat digunakan sebagai bahan bangunan pelindung pantai dan memilih tipe bangunan pelindung pantai yang sesuai kondisi hidro-oseanografi di lokasi studi dengan metode Analythic Hierarchy Process. Lokasi penelitian berada di Provinsi Sulawesi Tenggara, tepatnya di Pulau Kabaena, Kecamatan Kabaena Barat Desa Sikeli kabupaten Bombana. Pulau Kabaena memiliki luas 873 km2. Secara geografis terletak antara 4°22’ 59,4” - 5°28’ 26,7” Lintang Selatan serta antara 121°27’46,7”-122°09’,4” Bujur Timur. Hasil penelitian menunjukkan perairan disepanjang tanjung perak sangat mempengaruhi hidro-oseonografi disekitar pantai desa Sikeli. Kondisi ini berpengaruh terhadap pola pergerakan arus dan tinggi gelombang datang disekitar pantai desa Sikeli. Tinggi gelombang rata-rata yang paling besar merambat dari arah barat sebesar 0.49 m dengan presentase kajadian sebesar 32.42 %, disusul arah barat laut sebesar 0.39 m (20.56 %), arah tenggara sebesar 0.31 m (8.72 %) arah barat daya sebesar 0.31 m (7.99 %), arah utara sebesar 0.20 m (6.94 %), arah timur sebesar 0.15 m (11.81 %), arah selatan sebesar 0.12 m (3.42 %), dan arah timur laut sebesar 0.11 m (8.15 %). Pengambilan keputusan untuk memilih tipe bangunan pelindung pantai dengan metode AHP (Analytical Hierarchy Process) untuk penanganan abrasi pesisir pantai desa Sikeli berbasis bahan lokal diperoleh bahwa alternatif bangunan dengan nilai keterpilihan yang tertinggi adalah detached breakwater (0,4432) disusul groin (0,2479), sea-wall (0,1700) dan revetment (0.1389). Detached breakwater berfungsi untuk menahan laju sedimen kearah laut, mengurangi ketinggian dan meredam energi gelombang dan tidak dibangun sepanjang garis pantai yang akan dilindungi sehingga kapal nelayan dapat ditambat dipesisir pantai dengan aman. Abstract The Selection Type of Coastal Protection Structures in Sikeli Village Based on Local Materials. The coastal area is a meeting point between the sea and land areas, where this area is an area of interaction between terrestrial ecosystems and marine ecosystems which are very dynamic and influence each other. The purpose of this research is to determine local materials that can be used as coastal protection materials and to select the type of coastal protection that is suitable for the hydro-oceanographic conditions in the study location using the Analythic Hierarchy Process method. The research location is in Southeast Sulawesi Province, precisely on Kabaena Island, Kabaena Barat District, Sikeli Village, Bombana Regency. Kabaena Island has an area of 873 km2. Geographically it is located between 4° 22' 59.4"- 5° 28' 26.7" South Latitude and between 121° 27' 46.7 "-122° 09' 4" Longitude East. The results showed that the waters along Tanjung Perak greatly affect the hydro-oseonography around the coast of Sikeli village. This condition affects the current movement pattern and the height of the incoming waves around the coast of Sikeli village. The largest average wave height propagating from the west is 0.49 m with a kajadian percentage of 32.42%, followed by the northwest direction of 0.39 m (20.56%), southeast direction of 0.31 m (8.72%) to the southwest of 0.31 m (7.99%), to the north of 0.20 m (6.94%), to the east of 0.15 m (11.81%), to the south of 0.12 m (3.42%), and to the northeast of 0.11 m (8.15%). The decision to choose the type of coastal protection using the AHP (Analytical Hierarchy Process) method for the coastal abrasion management model in Sikeli village based on local materials was obtained that the alternative building with the highest electability value was the detached breakwater (0.4432) followed by groins (0.2479), sea-wall (0.1700) and revetment (0.1389). The detached breakwater model which functions to restrain the sediment rate towards the sea, reduce the height and reduce wave energy and is not built along the coastline which will be protected so that fishing boats can be moored to the coast safely.


1974 ◽  
Vol 1 (4) ◽  
pp. 285-294 ◽  
Author(s):  
Jedfrey M. Carlton

Covering broad areas of tropical shorelines are unique plants known as mangroves, which exhibit several structural and physiological modifications to the saline environment—especially in their root systems. Prop-roots and pneumatophores, two obvious modifications, allow mangroves to play a role in coastal geomorphology, either as land-builders or as stabilizers of substrates derived from classical sedimentation processes.Current data show that: (1) Provided with proper substrates, mangrove seedlings can be raised in the laboratory for later planting in the field, although on exposed beaches success ratios may be low. (2) Larger mangrove plants (1.0–5.0 m in height) may be transplanted with relative ease and appear to succeed with few or no mortalities resulting from the techniques used. (3) Pruning of mangroves appears to be a successful method of mangrove control, allowing their utilization for stabilization around housing developments. (4) Fossil evidence for mangroves as shoreline developers is suggested by the discovery of a fossil mangrove reef off the Miami, Florida, coast. However, submergence of near-by mangrove areas has occurred, as evidenced by sea-grass beds growing above buried peat in the bay bottom. (5) Black Mangroves may be more useful than Red Mangroves as shoreline stabilizers due to their cold-hardiness, ability to tolerate disturbed substrates, and rapid production of pneumatophores. (6) Insect and isopod damage to mangroves has been documented, and it has been suggested by several research workers that such damage may lead to increased erosion of coastlines in many areas of southern and central Florida. In addition, boring activities in Red Mangrove seedlings may result in decreased numbers of seedlings being available for new mangrove growth and colonization. (7) Mangroves have been suggested for use as stabilizers of substrates in conjunction with planned filling and sea wall construction.


1902 ◽  
Vol 149 (1902) ◽  
pp. 205-207
Author(s):  
F W WENTWORTH SHIELDS
Keyword(s):  

Phoenix ◽  
1972 ◽  
Vol 26 (2) ◽  
pp. 183 ◽  
Author(s):  
Elisabeth Alfoldi-Rosenbaum
Keyword(s):  

1998 ◽  
Vol 29 ◽  
pp. 35-83 ◽  
Author(s):  
David Smith ◽  
James Crow

AbstractThe fortifications of the Hellenistic and Roman city of Tocra are over 2 km long (including the sea-wall) and comprise a curtain wall up to 2 m wide flanked by 31 rectangular towers. Three main structural phases were noted in the survey carried out in 1966 by David Smith: (1) Hellenistic walls of isodomic ashlar, (2) later Hellenistic work of isodomic ashlar with bevelled edges, associated with the indented trace along the south rampart, and (3) an extensive rebuild of plain ashlar blocks including the towers and reconstruction to the East and West Gates, dateable, on the basis of Procopius, to the reign of Justinian. The general significance of the fortifications at Tocra is considered in the second part: these include the Hellenistic indented trace along the south side, later reinforced by towers in the sixth century AD. Also of wider importance was the use of an outer wall or proteichisma, and the pentagonal, pointed towers at the two main gates. Both these elements were unusual in Byzantine North Africa and they are discussed as part of the more general repertory of Byzantine fortifications. The unusual tower adjacent to the West Church is considered in the context of literary accounts. The article concludes by considering how the architecture and magnitude of the fortifications can allow a reassessment of the wider role of the city in the sixth and seventh century defences of Cyrenaica.


Author(s):  
Armen Zulham
Keyword(s):  

<p><strong>RINGKASAN</strong><br /><br />Pembangunan Giant Sea Wall (GSW) di Teluk Jakarta merupakan program lintas kementerian, yang dirancang untuk mendukung perekonomian dan mengendalikan banjir di Jakarta. Permasalahan GSW tersebut, tidak hanya terkait dengan aspek teknis kontruksi dan lingkungan, tetapi terkait juga dengan aspek sosial ekonomi tentang investasi dan pertumbuhan usaha perikanan.  Saat ini, pada kawasan itu terdapat berbagai investasi dan lapangan usaha perikanan. Data statistik, menunjukkan peran lapangan usaha perikanan dalam perekonomian Jakarta Utara menurun dari 0,10% pada tahun 2006 menjadi 0,08% pada tahun 2012.  Penurunan peran ini, bukan berarti lapangan usaha perikanan ini tidak penting.  Selama ini, lapangan usaha perikanan di kawasan itu merupakan sabuk pengaman yang mampu menyediakan lapangan kerja untuk 30 ribu orang dari berbagai kelompok masyarakat di Teluk Jakarta.  Invasi investasi sekitar  Rp. 600 triliun  untuk pembangunan GSW sampai tahun 2030, merupakan instrumen fiskal penting yang dapat mempercepat tumbuhnya perekonomian di kawasan tersebut.  Instrumen ini menurut beberapa pihak, dapat menjadi stimulus pembangunan, namun  pihak lain menganggap, dapat menjadi “jebakan fiskal untuk sektor perikanan”. Tulisan ini melihat, pembangunan GSW tersebut membuka peluang usaha baru bagi masyarakat perikanan. Namun, untuk memanfaatkan peluang itu diperlukan berbagai kebijakan yang inovatif.</p><p><br />Kata kunci : giant sea wall, demografi, nelayan, pembudidaya, pengolah  <br /><br /></p>


CORROSION ◽  
1958 ◽  
Vol 14 (6) ◽  
pp. 47-52
Author(s):  
L. J. WALDRON ◽  
M. H. PETERSON

Abstract The current output of full-scale arrays of several anode sizes in use by the U. S. Navy for the cathodic protection of ship hulls were determined. Impressed-current anodes formed from sheet steel were substituted for conventional galvanic anodes to reduce the weight and number of arrays necessary to obtain the desired information. Five anode sizes were investigated. A 1500-foot steel sea wall located in water with a resistivity of 34 to 38 ohm-cm acted as an un-polarizable cathode. The output currents were determined for driving potentials of 0.1, 0.2, 0.5, 0.7, and 1.0 between the cathode and the anode arrays; hence the data can be used to estimate for any galvanic material both the initial current output of an anode array, and the continuing current output against a cathode polarized to a known potential. The anodes in all arrays investigated suffered mutual interference as indicated by decreased current outputs from individual anodes as the number of anodes in the array increased. It was found that the addition of anodes is more efficient than a moderate separation of anodes in increasing the total current output. An empirical equation was derived from the data of the continuous linear arrays which relates the current output to total anode area and driving potential. It may be used to estimate the current output of arrays for which more specific data have not been obtained, but these estimations should be confirmed by experimentation wherever possible. 5.2.2


2007 ◽  
Vol 34 (11-12) ◽  
pp. 1786-1789
Author(s):  
Gerald Müller
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document