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Wadi Al-Garawi
Sadd el-Kafara ("Dam of the Infidels") was a masonry embankment dam on Wadi al-Garawi 10 km southeast of Helwan in Helwan Governorate, Egypt. The dam was built in the first half of the third millennium BC by the ancient Egyptians for flood control and is the oldest dam of such size in the world. Never completed, the dam was under construction for 10–12 years before being destroyed by a flood. It was rediscovered by Georg Schweinfurth in 1885. Specifications The dam was not finished but was about 111m long and 14m tall with a base width of 98m and crest width of 56m. The dam's core was 32m wide and consisted of 60,000 tons of earth and rock-fill. Surrounding the core were two loosely filled rubble and rock-fill layer-walls. The downstream wall was about 37m wide, the upstream wall about 29m wide and they encompassed of material. Encasing the dam were upstream and downstream walls created from limestone ashlars. The ashlars were set but not mortared in stepped rows. Each as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wadi Garawi
Sadd el-Kafara ("Dam of the Infidels") was a masonry embankment dam on Wadi al-Garawi 10 km southeast of Helwan in Helwan Governorate, Egypt. The dam was built in the first half of the third millennium BC by the ancient Egyptians for flood control and is the oldest dam of such size in the world. Never completed, the dam was under construction for 10–12 years before being destroyed by a flood. It was rediscovered by Georg Schweinfurth in 1885. Specifications The dam was not finished but was about 111m long and 14m tall with a base width of 98m and crest width of 56m. The dam's core was 32m wide and consisted of 60,000 tons of earth and rock-fill. Surrounding the core were two loosely filled rubble and rock-fill layer-walls. The downstream wall was about 37m wide, the upstream wall about 29m wide and they encompassed of material. Encasing the dam were upstream and downstream walls created from limestone ashlars. The ashlars were set but not mortared in stepped rows. Each as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georg August Schweinfurth
Georg August Schweinfurth (29 December 1836 – 19 September 1925) was a Baltic German botanist and ethnologist who explored East Central Africa. Life and explorations He was born at Riga, Latvia, then part of the Russian Empire. He was educated at the universities of Heidelberg, Munich and Berlin (1856–1862), where he particularly devoted himself to botany and palaeontology. Commissioned to arrange the collections brought from Sudan by Adalbert von Barnim and Robert Hartmann, his attention was directed to that region; and in 1863 he travelled round the shores of the Red Sea, repeatedly traversed the district between that sea and the Nile, passed on to Khartoum, and returned to Europe in 1866. In 1866 botanist A.Braun published '' Schweinfurthia'' which is a genus of flowering plants from Africa and Asia, belonging to the family Plantaginaceae and named in Georg August Schweinfurth's honour. His researches attracted so much attention that in 1868 the Berlin-based Alexan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dams In Egypt
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] |
Jawa Dam (Jordan)
Jawa is the site of the oldest proto-urban development in Jordan, dating from the late 4th millennium BC (Early Bronze Age). It is located in one of the driest areas of the Black Desert (Harrat al-Shamah) of Eastern Jordan. Remains of dams have been found, the largest of which is a masonry gravity dam and the oldest known dam in the world. It was used as a protection from flash floods. Discovery and history of investigation Jawa was first reported by French explorer Antoine Poidebard, who flew over and photographed the site in 1931, mistaking it for Roman ruins. Before and after Poidebard's discovery, several archaeological expeditions came close to but missed the site. Nelson Glueck visited it in 1947 but apparently failed to notice its significance, describing Jawa as a "small, filthy spring ..probably never more than a small police post." Finally, in 1950, an expedition led by epigrapher F. V. Winnett reached the site and documented some of the inscriptions there. Amongs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nile
The Nile, , Bohairic , lg, Kiira , Nobiin language, Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered the List of rivers by length, longest river in the world, though this has been contested by research suggesting that the Amazon River is slightly longer.Amazon Longer Than Nile River, Scientists Say Of the world's major rivers, the Nile is one of the smallest, as measured by annual flow in cubic metres of water. About long, its drainage basin covers eleven countries: the Democratic Republic of the Congo, Tanzania, Burundi, Rwanda, Uganda, Kenya, Ethiopia, Erit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spillway
A spillway is a structure used to provide the controlled release of water downstream from a dam or levee, typically into the riverbed of the dammed river itself. In the United Kingdom, they may be known as overflow channels. Spillways ensure that water does not damage parts of the structure not designed to convey water. Spillways can include floodgates and fuse plugs to regulate water flow and reservoir level. Such features enable a spillway to regulate downstream flow—by releasing water in a controlled manner before the reservoir is full, operators can prevent an unacceptably large release later. Other uses of the term "spillway" include bypasses of dams and outlets of channels used during high water, and outlet channels carved through natural dams such as moraines. Water normally flows over a spillway only during flood periods, when the reservoir has reached its capacity and water continues entering faster than it can be released. In contrast, an intake tower is a structure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ashlar
Ashlar () is finely dressed (cut, worked) stone, either an individual stone that has been worked until squared, or a structure built from such stones. Ashlar is the finest stone masonry unit, generally rectangular cuboid, mentioned by Vitruvius as opus isodomum, or less frequently trapezoidal. Precisely cut "on all faces adjacent to those of other stones", ashlar is capable of very thin joints between blocks, and the visible face of the stone may be quarry-faced or feature a variety of treatments: tooled, smoothly polished or rendered with another material for decorative effect. One such decorative treatment consists of small grooves achieved by the application of a metal comb. Generally used only on softer stone ashlar, this decoration is known as "mason's drag". Ashlar is in contrast to rubble masonry, which employs irregularly shaped stones, sometimes minimally worked or selected for similar size, or both. Ashlar is related but distinct from other stone masonry that is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms when these minerals precipitate out of water containing dissolved calcium. This can take place through both biological and nonbiological processes, though biological processes, such as the accumulation of corals and shells in the sea, have likely been more important for the last 540 million years. Limestone often contains fossils which provide scientists with information on ancient environments and on the evolution of life. About 20% to 25% of sedimentary rock is carbonate rock, and most of this is limestone. The remaining carbonate rock is mostly dolomite, a closely related rock, which contains a high percentage of the mineral dolomite, . ''Magnesian limestone'' is an obsolete and poorly-defined term used variously for dolomite, for limes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flood Control
Flood control methods are used to reduce or prevent the detrimental effects of flood waters."Flood Control", MSN Encarta, 2008 (see below: Further reading). Flood relief methods are used to reduce the effects of flood waters or high water levels. Flooding can be caused by a mix of both natural processes, such as extreme weather upstream, and human changes to waterbodies and runoff. Though building hard infrastructure to prevent flooding, such as flood walls, can be effective at managing flooding, increased best practice within landscape engineering is to rely more on soft infrastructure and natural systems, such as marshes and flood plains, for handling the increase in water. For flooding on coasts, coastal management practices have to not only handle changes water flow, but also natural processes like tides. Flood control and relief is a particularly important part of climate change adaptation and climate resilience, both sea level rise and changes in the weather (climate cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helwan
Helwan ( ar, حلوان ', , cop, ϩⲁⲗⲟⲩⲁⲛ, Halouan) is a city in Egypt and part of Greater Cairo, on the bank of the Nile, opposite the ruins of Memphis. Originally a southern suburb of Cairo, it served as the capital of the now defunct Helwan Governorate from April 2008 to April 2011, after which it was re-incorporated into the Cairo Governorate. The ''kism'' of Helwan had a population of 643,327 in the 2006 census.Central Agency for Public Mobilisation and Statistics, Population and Housing Census 2006, Population distribution by sex, gov: Cairo Retrieved on 2008-04-01. History The Helwan and Isnian cultures of the late |
Wadi Al-Garawi
Sadd el-Kafara ("Dam of the Infidels") was a masonry embankment dam on Wadi al-Garawi 10 km southeast of Helwan in Helwan Governorate, Egypt. The dam was built in the first half of the third millennium BC by the ancient Egyptians for flood control and is the oldest dam of such size in the world. Never completed, the dam was under construction for 10–12 years before being destroyed by a flood. It was rediscovered by Georg Schweinfurth in 1885. Specifications The dam was not finished but was about 111m long and 14m tall with a base width of 98m and crest width of 56m. The dam's core was 32m wide and consisted of 60,000 tons of earth and rock-fill. Surrounding the core were two loosely filled rubble and rock-fill layer-walls. The downstream wall was about 37m wide, the upstream wall about 29m wide and they encompassed of material. Encasing the dam were upstream and downstream walls created from limestone ashlars. The ashlars were set but not mortared in stepped rows. Each as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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