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Kanna Dam
The is a concrete gravity dam on the Kanna River in Ginoza, Okinawa Prefecture, Japan. The purpose of the dam is water supply and flood control. After studies were carried out in the 1970s(starting in 1973 and ending in 1978), construction on the dam began in 1982 and it was completed in 1992. The dam is tall and long. In order to retain the reservoir, a tall and long saddle dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, a ... was constructed directly northeast of the dam. A fish ladder was installed on the dam during construction to assist the migration of fish, shrimp and crabs. Mangroves downstream of the dam were restored after construction and the area is a tourist destination along with a habitat for water fowl. References {{Dams in Okinawa Prefecture Dams in Ok ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ginoza, Okinawa
is a village located in Kunigami District, Okinawa Prefecture, Japan. As of 2013 the village had a population of 5,544 and a population density of 180 persons per km2. The total area of Ginoza is , and 50% of the land area of the village is used for United States military bases. Etymology The kanji for Ginoza (宜野座) mean "suitable field in which to sit". Geography Ginoza is located on the eastern coast of the middle of the island of Okinawa. The village is located on the backbone of mountains that run north to south on Okinawa Island, and slopes gently to a broad coastline along the Pacific Ocean. The Kanna Dam was completed in 1993. Neighboring municipalities Ginoza borders three municipalities in Okinawa Prefecture. *Nago *Kin *Onna Districts Ginoza is divided into six districts. * * * * * * History The area of present-day Ginoza was historically agricultural. The area was, however, used as a retreat for members of the Yukatchu artistocratic class of the Ryuky ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most widely used building material. Its usage worldwide, ton for ton, is twice that of steel, wood, plastics, and aluminum combined. Globally, the ready-mix concrete industry, the largest segment of the concrete market, is projected to exceed $600 billion in revenue by 2025. This widespread use results in a number of environmental impacts. Most notably, the production process for cement produces large volumes of greenhouse gas emissions, leading to net 8% of global emissions. Other environmental concerns include widespread illegal sand mining, impacts on the surrounding environment such as increased surface runoff or urban heat island effect, and potential public health implications from toxic ingredients. Significant research and development is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravity Dam
A gravity dam is a dam constructed from concrete or stone masonry and designed to hold back water by using only the weight of the material and its resistance against the foundation to oppose the horizontal pressure of water pushing against it. Gravity dams are designed so that each section of the dam is stable and independent of any other dam section. Characteristics Gravity dams generally require stiff rock foundations of high bearing strength (slightly weathered to fresh), although in rare cases, they have been built on soil foundations. The bearing strength of the foundation limits the allowable position of the resultant force, influencing the overall stability. Also, the stiff nature of the gravity dam structure is unforgiving to differential foundation settlement, which can induce cracking of the dam structure. Gravity dams provide some advantages over embankment dams, the main advantage being that they can tolerate minor over-topping flows without damage, as the concre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Okinawa Prefecture
is a prefecture of Japan. Okinawa Prefecture is the southernmost and westernmost prefecture of Japan, has a population of 1,457,162 (as of 2 February 2020) and a geographic area of 2,281 km2 (880 sq mi). Naha is the capital and largest city of Okinawa Prefecture, with other major cities including Okinawa, Uruma, and Urasoe. Okinawa Prefecture encompasses two thirds of the Ryukyu Islands, including the Okinawa, Daitō and Sakishima groups, extending southwest from the Satsunan Islands of Kagoshima Prefecture to Taiwan ( Hualien and Yilan Counties). Okinawa Prefecture's largest island, Okinawa Island, is the home to a majority of Okinawa's population. Okinawa Prefecture's indigenous ethnic group are the Ryukyuan people, who also live in the Amami Islands of Kagoshima Prefecture. Okinawa Prefecture was ruled by the Ryukyu Kingdom from 1429 and unofficially annexed by Japan after the Invasion of Ryukyu in 1609. Okinawa Prefecture was officially founded in 1879 by the Empire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north toward the East China Sea, Philippine Sea, and Taiwan in the south. Japan is a part of the Ring of Fire, and spans Japanese archipelago, an archipelago of List of islands of Japan, 6852 islands covering ; the five main islands are Hokkaido, Honshu (the "mainland"), Shikoku, Kyushu, and Okinawa Island, Okinawa. Tokyo is the Capital of Japan, nation's capital and largest city, followed by Yokohama, Osaka, Nagoya, Sapporo, Fukuoka, Kobe, and Kyoto. Japan is the List of countries and dependencies by population, eleventh most populous country in the world, as well as one of the List of countries and dependencies by population density, most densely populated and Urbanization by country, urbanized. About three-fourths of Geography of Japan, the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saddle Dam
A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aquaculture, and navigability. Hydropower is often used in conjunction with dams to generate electricity. A dam can also be used to collect or store water which can be evenly distributed between locations. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees (also known as dikes) are used to manage or prevent water flow into specific land regions. The earliest known dam is the Jawa Dam in Jordan, dating to 3,000 BC. The word ''dam'' can be traced back to Middle English, and before that, from Middle Dutch, as seen in the names of many old cities, such as Amsterdam and Rotterdam. History Ancient dams Early dam building took place in Mesopotamia and the Middle East. Dams were used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Ladder
A fish ladder, also known as a fishway, fish pass, fish steps, or fish cannon is a structure on or around artificial and natural barriers (such as dams, locks and waterfalls) to facilitate diadromous fishes' natural migration as well as movements of potamodromous species. Most fishways enable fish to pass around the barriers by swimming and leaping up a series of relatively low steps (hence the term ''ladder'') into the waters on the other side. The velocity of water falling over the steps has to be great enough to attract the fish to the ladder, but it cannot be so great that it washes fish back downstream or exhausts them to the point of inability to continue their journey upriver. History Written reports of rough fishways date to 17th-century France, where bundles of branches were used to make steps in steep channels to bypass obstructions. A pool and weir salmon ladder was built around 1830 by James Smith, a Scottish engineer on the River Teith, near Deanston, Perthshire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mangrove
A mangrove is a shrub or tree that grows in coastal saline water, saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evolution in several plant families. They occur worldwide in the tropics and subtropics and even some temperate coastal areas, mainly between latitudes 30° N and 30° S, with the greatest mangrove area within 5° of the equator. Mangrove plant families first appeared during the Late Cretaceous to Paleocene epochs, and became widely distributed in part due to the plate tectonics, movement of tectonic plates. The oldest known fossils of Nypa fruticans, mangrove palm date to 75 million years ago. Mangroves are salt-tolerant trees, also called halophytes, and are adapted to live in harsh coastal conditions. They contain a complex salt filtration system and a complex root system to cope with saltwater immersion and wave action. They are ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dams In Okinawa Prefecture
A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aquaculture, and navigability. Hydropower is often used in conjunction with dams to generate electricity. A dam can also be used to collect or store water which can be evenly distributed between locations. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees (also known as dikes) are used to manage or prevent water flow into specific land regions. The earliest known dam is the Jawa Dam in Jordan, dating to 3,000 BC. The word ''dam'' can be traced back to Middle English, and before that, from Middle Dutch, as seen in the names of many old cities, such as Amsterdam and Rotterdam. History Ancient dams Early dam building took place in Mesopotamia and the Middle East. Dams were used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravity Dams
A gravity dam is a dam constructed from concrete or stone masonry and designed to hold back water by using only the weight of the material and its resistance against the foundation to oppose the horizontal pressure of water pushing against it. Gravity dams are designed so that each section of the dam is stable and independent of any other dam section. Characteristics Gravity dams generally require stiff rock foundations of high bearing strength (slightly weathered to fresh), although in rare cases, they have been built on soil foundations. The bearing strength of the foundation limits the allowable position of the resultant force, influencing the overall stability. Also, the stiff nature of the gravity dam structure is unforgiving to differential foundation settlement, which can induce cracking of the dam structure. Gravity dams provide some advantages over embankment dams, the main advantage being that they can tolerate minor over-topping flows without damage, as the concre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dams Completed In 1992
A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aquaculture, and navigability. Hydropower is often used in conjunction with dams to generate electricity. A dam can also be used to collect or store water which can be evenly distributed between locations. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees (also known as dikes) are used to manage or prevent water flow into specific land regions. The earliest known dam is the Jawa Dam in Jordan, dating to 3,000 BC. The word ''dam'' can be traced back to Middle English, and before that, from Middle Dutch, as seen in the names of many old cities, such as Amsterdam and Rotterdam. History Ancient dams Early dam building took place in Mesopotamia and the Middle East. Dams were us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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