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Grevelingenmeer
Grevelingen or Grevelingenmeer (Lake Grevelingen) is a closed off part of the Rhine-Meuse estuary on the border of the Dutch provinces of South Holland and Zeeland. It is situated between the islands of Goeree-Overflakkee (South Holland) and Schouwen-Duiveland (Zeeland) and was closed off as part of the Delta Works, a huge engineering project designed to protect the southwestern part of the Netherlands from flooding. The Brouwersdam, a dike connecting the two islands on the west, closes off the Grevelingen from the North Sea. The Grevelingendam, the dike on the east, blocks the inflow of Rhine and Meuse water. Since its closure in 1971 the saltwater of the Grevelingen slowly started to become brackish due to rainwater and excess polderwater from the islands, but the Dutch changed their mind and decided that they wanted to preserve the saline biotope. Therefore, in 1978 a sluice was created under the Brouwersdam, partially restoring and maintaining the saline character of the Gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schouwen-Duiveland
Schouwen-Duiveland () is a municipality and an island in the southwestern Netherlands province of Zeeland. The municipality has 33,737 inhabitants (1 January 2016) and covers an area of (of which is water). The northside of the island has two fixed connections to Goeree-Overflakkee, the Brouwersdam and the Grevelingen. The southside has two fixed connections to cross the Oosterschelde to North Beveland, the Stormvloed Kering or Oosterscheldedam, part of the Delta Works and the Zeeland Bridge. The island is mostly flat and is, besides a small area, below the sea level. On the western tip is a dune whose highest point is about 42 meters above sea level. The island is, in the summer, very popular with (German) tourists. The Renesse area is a popular holiday destination for young people. The Brouwersdam is a dam, part of the Delta Works, from Schouwen-Duiveland to Goedereede, the west part of the island of Goeree-Overflakkee in South Holland. History The island of Schouwen-Duivel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Works
The Delta Works ( nl, Deltawerken) is a series of construction projects in the southwest of the Netherlands to protect a large area of land around the Rhine–Meuse–Scheldt delta from the sea. Constructed between 1954 and 1997, the works consist of dams, sluices, locks, dykes, levees, and storm surge barriers located in the provinces of South Holland and Zeeland. The aim of the dams, sluices, and storm surge barriers was to shorten the Dutch coastline, thus reducing the number of dikes that had to be raised. Along with the Zuiderzee Works, the Delta Works have been declared one of the Seven Wonders of the Modern World by the American Society of Civil Engineers. History The estuaries of the rivers Rhine, Meuse and Schelde have been subject to flooding over the centuries. After building the Afsluitdijk (19271932), the Dutch started studying the damming of the Rhine-Meuse Delta. Plans were developed to shorten the coastline and turn the delta into a group of freshwater ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goeree-Overflakkee
Goeree-Overflakkee () is the southernmost delta island of the province of South Holland, Netherlands. It is separated from Voorne-Putten and Hoeksche Waard by the Haringvliet, from the mainland of North Brabant by the Volkerak, and from Schouwen-Duiveland by Lake Grevelingen. Since 2013, Goeree-Overflakkee has also been a municipality, consisting from west to east of the former municipalities of Goedereede, Dirksland, Middelharnis, and Oostflakkee. The largest towns are Sommelsdijk, Middelharnis, Ouddorp, and Dirksland. Despite being part of the province of South Holland, the island's scenery and dialect are more closely related to Zeeland than to Holland. On the island they speak a form of Zeelandic, namely in the west and in the east. History The island was detached from the mainland when the Haringvliet formed as a result of two major flooding events. The first was in 1216, which breached the dunes of Voorne and created a deep saltwater inlet. In the St. Elizabeth flood ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brouwersdam
The Brouwersdam is the seventh structure of the Delta Works in the Netherlands. Brouwersdam forms a barrier across the former estuary known as the Brouwershavense Gat. As a result, the area of water became known as the Grevelingenmeer. Construction The Grevelingendam between Goeree-Overflakkee and Schouwen-Duiveland was completed in 1965. The Gravelingen south of Goeree-Overflakkee were still connected to the North Sea. The storm surge could therefore be higher here, so dykes were raised on the south side of the island in 1965. Construction of the Brouwersdam was begun immediately after the Gavelingendam was completed in order to shorten the period of higher flood. After more than six years, in the spring of 1971, the dam was finished. Between 1964 and 1971 there had been some very high water levels. In November 1966 the water was just a few centimeters below the level of the infamous floods of February 1, 1953. Construction of the six-kilometer long dam was begun in 1962. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ramsar Convention
The Ramsar Convention on Wetlands of International Importance Especially as Waterfowl Habitat is an international treaty for the conservation and sustainable use of Ramsar sites (wetlands). It is also known as the Convention on Wetlands. It is named after the city of Ramsar in Iran, where the convention was signed in 1971. Every three years, representatives of the contracting parties meet as the Conference of the Contracting Parties (COP), the policy-making organ of the convention which adopts decisions (resolutions and recommendations) to administer the work of the convention and improve the way in which the parties are able to implement its objectives. COP12 was held in Punta del Este, Uruguay, in 2015. COP13 was held in Dubai, United Arab Emirates, in October 2018. List of wetlands of international importance The list of wetlands of international importance included 2,331 Ramsar sites in May 2018 covering over . The countries with most sites are the United Kingdo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photic Zone
The photic zone, euphotic zone, epipelagic zone, or sunlight zone is the uppermost layer of a body of water that receives sunlight, allowing phytoplankton to perform photosynthesis. It undergoes a series of physical, chemical, and biological processes that supply nutrients into the upper water column. The photic zone is home to the majority of aquatic life due to the activity (primary production) of the phytoplankton. Photosynthesis in photic zone In the photic zone, the photosynthesis rate exceeds the respiration rate. This is due to the abundant solar energy which is used as an energy source for photosynthesis by primary producers such as phytoplankton. These phytoplankton grow extremely quickly because of sunlight's heavy influence, enabling it to be produced at a fast rate. In fact, ninety five percent of photosynthesis in the ocean occurs in the photic zone. Therefore, if we go deeper, beyond the photic zone, such as into the compensation point, there is little to no phyto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mussel
Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and Freshwater bivalve, freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which are often more or less rounded or oval. The word "mussel" is frequently used to mean the bivalves of the marine family Mytilidae, most of which live on exposed shores in the intertidal zone, attached by means of their strong Byssus, byssal threads ("beard") to a firm substrate. A few species (in the genus ''Bathymodiolus'') have colonised hydrothermal vents associated with deep ocean ridges. In most marine mussels the shell is longer than it is wide, being wedge-shaped or asymmetrical. The external colour of the shell is often dark blue, blackish, or brown, while the interior is silvery and somewhat nacreous. The common name "mussel" is also used for many freshwater bivalves, including the freshwater pearl mussels. F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oyster
Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not all oysters are in the superfamily Ostreoidea. Some types of oysters are commonly consumed (cooked or raw), and in some locales are regarded as a delicacy. Some types of pearl oysters are harvested for the pearl produced within the mantle. Windowpane oysters are harvested for their translucent shells, which are used to make various kinds of decorative objects. Etymology The word ''oyster'' comes from Old French , and first appeared in English during the 14th century. The French derived from the Latin , the feminine form of , which is the latinisation of the Ancient Greek () 'oyster'. Compare () 'bone'. Types True oysters True oysters are members of the family Ostreidae. This family includes the edible oysters, which mainly belong t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seal (animal)
Pinnipeds (pronounced ), commonly known as seals, are a widely distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammals. They comprise the extant families Odobenidae (whose only living member is the walrus), Otariidae (the eared seals: sea lions and fur seals), and Phocidae (the earless seals, or true seals). There are 34 extant species of pinnipeds, and more than 50 extinct species have been described from fossils. While seals were historically thought to have descended from two ancestral lines, molecular evidence supports them as a monophyletic lineage (descended from one ancestral line). Pinnipeds belong to the order Carnivora; their closest living relatives are musteloids (weasels, raccoons, skunks, and red pandas), having diverged about 50 million years ago. Seals range in size from the and Baikal seal to the and southern elephant seal male, which is also the largest member of the order Carnivora. Several species exhib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sluice
Sluice ( ) is a word for a channel controlled at its head by a movable gate which is called a sluice gate. A sluice gate is traditionally a wood or metal barrier sliding in grooves that are set in the sides of the waterway and can be considered as a bottom opening in a wall. Sluice gates are one of the most common hydraulic structures in controlling flow rate and water level in open channels such as rivers and canals. They also could be used to measure the flow. A water channel containing a sluice gate forms a type of lock to manage the water flow and water level. It can also be an open channel which processes material, such as a River Sluice used in gold prospecting or fossicking. A mill race, leet, flume, penstock or lade is a sluice channeling water toward a water mill. The terms sluice, sluice gate, knife gate, and slide gate are used interchangeably in the water and wastewater control industry. They are also used in wastewater treatment plants and to recover minerals in minin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seawater
Seawater, or salt water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has approximately of dissolved salts (predominantly sodium () and chloride () ions). The average density at the surface is 1.025 kg/L. Seawater is denser than both fresh water and pure water (density 1.0 kg/L at ) because the dissolved salts increase the mass by a larger proportion than the volume. The freezing point of seawater decreases as salt concentration increases. At typical salinity, it freezes at about . The coldest seawater still in the liquid state ever recorded was found in 2010, in a stream under an Antarctic glacier: the measured temperature was . Seawater pH is typically limited to a range between 7.5 and 8.4. However, there is no universally accepted reference pH-scale for seawater and the difference between measurement ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravity, gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables can be used for any given locale to find the predicted times and amplitude (or "tidal range"). The predictions are influenced by many factors including the alignment of the Sun and Moon, the #Phase and amplitude, phase and amplitude of the tide (pattern of tides in the deep ocean), the amphidromic systems of the oceans, and the shape of the coastline and near-shore bathymetry (see ''#Timing, Timing''). They are however only predictions, the actual time and height of the tide is affected by wind and atmospheric pressure. Many shorelines experience semi-diurnal tides—two nearly equal high and low tides each day. Other locations have a diurnal cycle, diurnal tide—one high and low tide each day. A "mixed tide"—two uneven magnitude ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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