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110-628: The project was started and finished in the 1950s. It consists of a dam , a reservoir , and a hydro power plant . The dam is a reinforced concrete structure with a height of 127 m (417 ft). It formed and holds the Bicaz Lake reservoir, also known as Mountain Spring Lake ("Lacul Izvorul Muntelui"). The reservoir is the largest artificial lake in Romania; it manages river levels downstream, provides fishing, attracts tourism, fuels

220-509: A Romanian building or structure is a stub . You can help Misplaced Pages by expanding it . This article about a hydroelectric power plant is a stub . You can help Misplaced Pages by expanding it . 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

330-401: A balancing compression stress in the downstream face, providing additional economy. For this type of dam, it is essential to have an impervious foundation with high bearing strength. Permeable foundations have a greater likelihood of generating uplift pressures under the dam. Uplift pressures are hydrostatic pressures caused by the water pressure of the reservoir pushing up against the bottom of

440-544: A dam as "jurisdictional" or "non-jurisdictional" varies by location. In the United States, each state defines what constitutes a non-jurisdictional dam. In the state of Colorado a non-jurisdictional dam is defined as a dam creating a reservoir with a capacity of 100 acre-feet or less and a surface area of 20 acres or less and with a height measured as defined in Rules 4.2.5.1. and 4.2.19 of 10 feet or less. In contrast,

550-499: A dam that directed waterflow. It was finished in 251 BC. A large earthen dam, made by Sunshu Ao , the prime minister of Chu (state) , flooded a valley in modern-day northern Anhui Province that created an enormous irrigation reservoir (100 km (62 mi) in circumference), a reservoir that is still present today. Roman dam construction was characterized by "the Romans' ability to plan and organize engineering construction on

660-493: A distinct vertical curvature to it as well lending it the vague appearance of a concave lens as viewed from downstream. The multiple-arch dam consists of a number of single-arch dams with concrete buttresses as the supporting abutments, as for example the Daniel-Johnson Dam , Québec, Canada. The multiple-arch dam does not require as many buttresses as the hollow gravity type but requires a good rock foundation because

770-478: A grand scale." Roman planners introduced the then-novel concept of large reservoir dams which could secure a permanent water supply for urban settlements over the dry season. Their pioneering use of water-proof hydraulic mortar and particularly Roman concrete allowed for much larger dam structures than previously built, such as the Lake Homs Dam , possibly the largest water barrier to that date, and

880-511: A minor tributary of the Nieuwe Maas . The central square of Amsterdam, covering the original site of the 800-year-old dam, still carries the name Dam Square . The Romans were the first to build arch dams , where the reaction forces from the abutment stabilizes the structure from the external hydrostatic pressure , but it was only in the 19th century that the engineering skills and construction materials available were capable of building

990-509: A notable increase in interest in SHPs. Couto and Olden (2018) conducted a global study and found 82,891 small hydropower plants (SHPs) operating or under construction. Technical definitions of SHPs, such as their maximum generation capacity, dam height, reservoir area, etc., vary by country. A dam is non-jurisdictional when its size (usually "small") excludes it from being subject to certain legal regulations. The technical criteria for categorising

1100-649: A profession based on a rigorously applied scientific theoretical framework. This new emphasis was centered around the engineering faculties of universities in France and in the United Kingdom. William John Macquorn Rankine at the University of Glasgow pioneered the theoretical understanding of dam structures in his 1857 paper On the Stability of Loose Earth . Rankine theory provided a good understanding of

1210-773: A rivalry that would become known as the Great Game . Mahan realized not only the strategic importance of the region, but also of its center, the Persian Gulf . He labeled the area surrounding the Persian Gulf as the Middle East. He said that, beyond Egypt's Suez Canal , the Gulf was the most important passage for Britain to control in order to keep the Russians from advancing towards British India . Mahan first used

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1320-566: A settling pond, and a 1,000 m (3,300 ft) canal to a distribution tank. These works were not finished until 325 AD when the dam permitted the irrigation of 25,000 acres (100 km ). Eflatun Pınar is a Hittite dam and spring temple near Konya , Turkey. It is thought to date from the Hittite empire between the 15th and 13th centuries BC. The Kallanai is constructed of unhewn stone, over 300 m (980 ft) long, 4.5 m (15 ft) high and 20 m (66 ft) wide, across

1430-808: A vital role in the Middle East, and they represent 40.5% of Lebanon, where the Lebanese president , half of the cabinet, and half of the parliament follow one of the various Lebanese Christian rites. There are also important minority religions like the Baháʼí Faith , Yarsanism , Yazidism , Zoroastrianism , Mandaeism , Druze , and Shabakism , and in ancient times the region was home to Mesopotamian religions , Canaanite religions , Manichaeism , Mithraism and various monotheist gnostic sects. The six top languages, in terms of numbers of speakers, are Arabic , Persian , Turkish , Kurdish , Modern Hebrew and Greek . About 20 minority languages are also spoken in

1540-408: A whole dam itself, that dam also would be held in place by gravity, i.e., there is no tension in the upstream face of the dam holding the top of the dam down. The designer does this because it is usually more practical to make a dam of material essentially just piled up than to make the material stick together against vertical tension. The shape that prevents tension in the upstream face also eliminates

1650-545: Is Aramaic and its dialects are spoken mainly by Assyrians and Mandaeans , with Western Aramaic still spoken in two villages near Damascus, Syria. There is also an Oasis Berber -speaking community in Egypt where the language is also known as Siwa . It is a non-Semitic Afro-Asiatic sister language. Persian is the second most spoken language. While it is primarily spoken in Iran and some border areas in neighbouring countries,

1760-539: Is Middle Eastern and the derived noun is Middle Easterner . While non-Eurocentric terms such as "Southwest Asia" or "Swasia" have been sparsely used, the classificiation of the African country, Egypt, among those counted in the Middle East challenges the usefulness of using such terms. The description Middle has also led to some confusion over changing definitions. Before the First World War , "Near East"

1870-424: Is dependent on the strength of the side wall abutments, hence not only should the arch be well seated on the side walls but also the character of the rock should be carefully inspected. Two types of single-arch dams are in use, namely the constant-angle and the constant-radius dam. The constant-radius type employs the same face radius at all elevations of the dam, which means that as the channel grows narrower towards

1980-480: 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 word dam can be traced back to Middle English , and before that, from Middle Dutch , as seen in

2090-646: Is present in areas in neighboring countries. It is a member of the Turkic languages , which have their origins in East Asia. Another Turkic language, Azerbaijani , is spoken by Azerbaijanis in Iran. The fourth-most widely spoken language, Kurdish , is spoken in the countries of Iran, Iraq, Syria and Turkey, Sorani Kurdish is the second official language in Iraq (instated after the 2005 constitution) after Arabic. Hebrew

2200-471: Is sloped the distribution is more complicated. The normal component of the weight of the arch ring may be taken by the arch action, while the normal hydrostatic pressure will be distributed as described above. For this type of dam, firm reliable supports at the abutments (either buttress or canyon side wall) are more important. The most desirable place for an arch dam is a narrow canyon with steep side walls composed of sound rock. The safety of an arch dam

2310-399: Is the more widely used of the two, though the hollow dam is frequently more economical to construct. Grand Coulee Dam is a solid gravity dam and Braddock Locks & Dam is a hollow gravity dam. A gravity dam can be combined with an arch dam into an arch-gravity dam for areas with massive amounts of water flow but less material available for a pure gravity dam. The inward compression of

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2420-429: Is the official language of Israel , with Arabic given a special status after the 2018 Basic law lowered its status from an official language prior to 2018. Hebrew is spoken and used by over 80% of Israel's population, the other 20% using Arabic. Modern Hebrew only began being spoken in the 20th century after being revived in the late 19th century by Elizer Ben-Yehuda (Elizer Perlman) and European Jewish settlers, with

2530-590: Is the thinnest arch dam in the world and one of the oldest arch dams in Asia. It was constructed some 700 years ago in Tabas county , South Khorasan Province , Iran . It stands 60 meters tall, and in crest is a one meter width. Some historians believe the dam was built by Shāh Abbās I, whereas others believe that he repaired it. In the Netherlands , a low-lying country, dams were often built to block rivers to regulate

2640-728: The Maghreb , the western part). Even though the term originated in the West, countries of the Middle East that use languages other than Arabic also use that term in translation. For instance, the Persian equivalent for Middle East is خاورمیانه ( Khāvar-e miyāneh ), the Hebrew is המזרח התיכון ( hamizrach hatikhon ), and the Turkish is Orta Doğu. Traditionally included within the Middle East are Arabia , Asia Minor , East Thrace , Egypt , Iran ,

2750-516: The Arab world . The most populous countries in the region are Egypt, Turkey, and Iran, while Saudi Arabia is the largest Middle Eastern country by area. The history of the Middle East dates back to ancient times , and it was long considered the "cradle of civilization". The geopolitical importance of the region has been recognized and competed for during millennia. The Abrahamic religions, Judaism , Christianity , and Islam , have their origins in

2860-842: The Arabian Peninsula ( Magan , Sheba , Ubar ). The Near East was first largely unified under the Neo Assyrian Empire , then the Achaemenid Empire followed later by the Macedonian Empire and after this to some degree by the Iranian empires (namely the Parthian and Sassanid Empires ), the Roman Empire and Byzantine Empire . The region served as the intellectual and economic center of

2970-547: The Baháʼí Faith . Throughout its history the Middle East has been a major center of world affairs; a strategically, economically, politically, culturally, and religiously sensitive area. The region is one of the regions where agriculture was independently discovered, and from the Middle East it was spread, during the Neolithic, to different regions of the world such as Europe, the Indus Valley and Eastern Africa. Prior to

3080-532: The Central Powers , was defeated by the British Empire and their allies and partitioned into a number of separate nations, initially under British and French Mandates . Other defining events in this transformation included the establishment of Israel in 1948 and the eventual departure of European powers, notably Britain and France by the end of the 1960s. They were supplanted in some part by

3190-657: The Far East ). The term "Middle East" has led to some confusion over its changing definitions. Since the late 20th century, it has been criticized as being too Eurocentric . The region includes the vast majority of the territories included in the closely associated definition of West Asia , but without the South Caucasus . It also includes all of Egypt (not just the Sinai ) and all of Turkey (including East Thrace ). Most Middle Eastern countries (13 out of 18) are part of

3300-657: The Fayum Depression to the Nile in Middle Egypt. Two dams called Ha-Uar running east–west were built to retain water during the annual flood and then release it to surrounding lands. The lake called Mer-wer or Lake Moeris covered 1,700 km (660 sq mi) and is known today as Birket Qarun. By the mid-late third millennium BC, an intricate water-management system in Dholavira in modern-day India

3410-579: The Harbaqa Dam , both in Roman Syria . The highest Roman dam was the Subiaco Dam near Rome ; its record height of 50 m (160 ft) remained unsurpassed until its accidental destruction in 1305. Roman engineers made routine use of ancient standard designs like embankment dams and masonry gravity dams. Apart from that, they displayed a high degree of inventiveness, introducing most of

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3520-693: The International Organization for Migration , there are 13 million first-generation migrants from Arab nations in the world, of which 5.8 reside in other Arab countries. Expatriates from Arab countries contribute to the circulation of financial and human capital in the region and thus significantly promote regional development. In 2009 Arab countries received a total of US$ 35.1 billion in remittance in-flows and remittances sent to Jordan , Egypt and Lebanon from other Arab countries are 40 to 190 per cent higher than trade revenues between these and other Arab countries. In Somalia ,

3630-639: The Levant , Mesopotamia , and the Socotra Archipelago . The region includes 17 UN -recognized countries and one British Overseas Territory . Various concepts are often paralleled to the Middle East, most notably the Near East , Fertile Crescent , and Levant . These are geographical concepts, which refer to large sections of the modern-day Middle East, with the Near East being the closest to

3740-618: The National Inventory of Dams (NID). Middle East The Middle East (term originally coined in English language) is a geopolitical region encompassing the Arabian Peninsula , the Levant , Turkey , Egypt , Iran , and Iraq . The term came into widespread usage by the United Kingdom and western European nations in the early 20th century as a replacement of the term Near East (both were in contrast to

3850-736: The Nile Delta in Egypt, the Tigris and Euphrates watersheds of Mesopotamia , and the basin of the Jordan River that spans most of the Levant. These regions are collectively known as the Fertile Crescent , and comprise the core of what historians had long referred to as the cradle of civilization (multiple regions of the world have since been classified as also having developed independent, original civilizations). Conversely,

3960-581: The Sassanid Empire . However, it would be the later Islamic Caliphates of the Middle Ages , or Islamic Golden Age which began with the Islamic conquest of the region in the 7th century AD, that would first unify the entire Middle East as a distinct region and create the dominant Islamic Arab ethnic identity that largely (but not exclusively) persists today. The 4 caliphates that dominated

4070-787: The Somali Civil War has greatly increased the size of the Somali diaspora , as many of the best educated Somalis left for Middle Eastern countries as well as Europe and North America . Non-Arab Middle Eastern countries such as Turkey , Israel and Iran are also subject to important migration dynamics. A fair proportion of those migrating from Arab nations are from ethnic and religious minorities facing persecution and are not necessarily ethnic Arabs, Iranians or Turks. Large numbers of Kurds , Jews , Assyrians , Greeks and Armenians as well as many Mandeans have left nations such as Iraq, Iran, Syria and Turkey for these reasons during

4180-645: The University of Oxford published a study of the cost of large dams – based on the largest existing dataset – documenting significant cost overruns for a majority of dams and questioning whether benefits typically offset costs for such dams. Dams can be formed by human agency, natural causes, or even by the intervention of wildlife such as beavers . Man-made dams are typically classified according to their size (height), intended purpose or structure. Based on structure and material used, dams are classified as easily created without materials, arch-gravity dams , embankment dams or masonry dams , with several subtypes. In

4290-491: The first native Hebrew speaker being born in 1882. Greek is one of the two official languages of Cyprus , and the country's main language. Small communities of Greek speakers exist all around the Middle East; until the 20th century it was also widely spoken in Asia Minor (being the second most spoken language there, after Turkish) and Egypt. During the antiquity, Ancient Greek was the lingua franca for many areas of

4400-614: The Arabic equivalent of Middle East (Arabic: الشرق الأوسط ash-Sharq al-Awsaṭ ) has become standard usage in the mainstream Arabic press. It comprises the same meaning as the term "Middle East" in North American and Western European usage. The designation, Mashriq , also from the Arabic root for East , also denotes a variously defined region around the Levant , the eastern part of the Arabic-speaking world (as opposed to

4510-544: The British began construction in 1898. The project was designed by Sir William Willcocks and involved several eminent engineers of the time, including Sir Benjamin Baker and Sir John Aird , whose firm, John Aird & Co. , was the main contractor. Capital and financing were furnished by Ernest Cassel . When initially constructed between 1899 and 1902, nothing of its scale had ever before been attempted; on completion, it

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4620-520: The Colorado River is a constant-angle arch dam. A similar type is the double-curvature or thin-shell dam. Wildhorse Dam near Mountain City, Nevada , in the United States is an example of the type. This method of construction minimizes the amount of concrete necessary for construction but transmits large loads to the foundation and abutments. The appearance is similar to a single-arch dam but with

4730-628: The Colorado River. By 1997, there were an estimated 800,000 dams worldwide, with some 40,000 of them over 15 meters high. Early dam building took place in Mesopotamia and the Middle East . Dams were used to control water levels, for Mesopotamia's weather affected the Tigris and Euphrates Rivers. The earliest known dam is the Jawa Dam in Jordan , 100 kilometres (62 mi) northeast of

4840-531: The Levant, all originated in the Fertile Crescent and Nile Valley regions of the ancient Near East. These were followed by the Hittite , Greek , Hurrian and Urartian civilisations of Asia Minor ; Elam , Persia and Median civilizations in Iran , as well as the civilizations of the Levant (such as Ebla , Mari , Nagar , Ugarit , Canaan , Aramea , Mitanni , Phoenicia and Israel ) and

4950-595: The Levantine coast and most of Turkey have relatively temperate climates typical of the Mediterranean , with dry summers and cool, wet winters. Most of the countries that border the Persian Gulf have vast reserves of petroleum . Monarchs of the Arabian Peninsula in particular have benefitted economically from petroleum exports. Because of the arid climate and dependence on the fossil fuel industry,

5060-598: The Middle Ages, dams were built in the Netherlands to regulate water levels and prevent sea intrusion. In the 19th century, large-scale arch dams were constructed around the British Empire, marking advances in dam engineering techniques. The era of large dams began with the construction of the Aswan Low Dam in Egypt in 1902. The Hoover Dam, a massive concrete arch-gravity dam, was built between 1931 and 1936 on

5170-980: The Middle East for more than 600 years were the Rashidun Caliphate , the Umayyad caliphate , the Abbasid caliphate and the Fatimid caliphate . Additionally, the Mongols would come to dominate the region, the Kingdom of Armenia would incorporate parts of the region to their domain, the Seljuks would rule the region and spread Turko-Persian culture, and the Franks would found the Crusader states that would stand for roughly two centuries. Josiah Russell estimates

5280-416: The Middle East in its geographical meaning. Due to it primarily being Arabic speaking, the Maghreb region of North Africa is sometimes included. The countries of the South Caucasus  – Armenia , Azerbaijan , and Georgia  – are occasionally included in definitions of the Middle East. " Greater Middle East " is a political term coined by the second Bush administration in

5390-421: The Middle East is both a major contributor to climate change and a region that is expected to be severely adversely affected by it. Other concepts of the region exist, including the broader Middle East and North Africa (MENA), which includes states of the Maghreb and the Sudan . The term the " Greater Middle East " also includes parts of East Africa , Mauritania , Afghanistan , Pakistan , and sometimes

5500-504: The Middle East. Arabic, with all its dialects, is the most widely spoken language in the Middle East, with Literary Arabic being official in all North African and in most West Asian countries. Arabic dialects are also spoken in some adjacent areas in neighbouring Middle Eastern non-Arab countries. It is a member of the Semitic branch of the Afro-Asiatic languages. Several Modern South Arabian languages such as Mehri and Soqotri are also spoken in Yemen and Oman. Another Semitic language

5610-407: The Middle East. Arabs constitute the main ethnic group in the region, followed by Turks , Persians , Kurds , Azeris , Copts , Jews , Assyrians , Iraqi Turkmen , Yazidis , and Greek Cypriots . The Middle East generally has a hot, arid climate, especially in the Arabian and Egyptian regions. Several major rivers provide irrigation to support agriculture in limited areas here, such as

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5720-408: The Middle East. For the period between the 1970s and 1990s, the Arab states of the Persian Gulf in particular provided a rich source of employment for workers from Egypt, Yemen and the countries of the Levant, while Europe had attracted young workers from North African countries due both to proximity and the legacy of colonial ties between France and the majority of North African states." According to

5830-400: The Roman Empire and played an exceptionally important role due to its periphery on the Sassanid Empire . Thus, the Romans stationed up to five or six of their legions in the region for the sole purpose of defending it from Sassanid and Bedouin raids and invasions. From the 4th century CE onwards, the Middle East became the center of the two main powers at the time, the Byzantine Empire and

5940-400: The South Caucasus and Central Asia . The term "Middle East" may have originated in the 1850s in the British India Office . However, it became more widely known when United States naval strategist Alfred Thayer Mahan used the term in 1902 to "designate the area between Arabia and India". During this time the British and Russian empires were vying for influence in Central Asia ,

6050-437: The United States alone, there are approximately 2,000,000 or more "small" dams that are not included in the Army Corps of Engineers National Inventory of dams . Records of small dams are kept by state regulatory agencies and therefore information about small dams is dispersed and uneven in geographic coverage. Countries worldwide consider small hydropower plants (SHPs) important for their energy strategies, and there has been

6160-457: The World Commission on Dams also includes in the "large" category, dams which are between 5 and 15 m (16 and 49 ft) high with a reservoir capacity of more than 3 million cubic metres (2,400  acre⋅ft ). Hydropower dams can be classified as either "high-head" (greater than 30 m in height) or "low-head" (less than 30 m in height). As of 2021 , ICOLD's World Register of Dams contains 58,700 large dam records. The tallest dam in

6270-403: The arch dam, stability is obtained by a combination of arch and gravity action. If the upstream face is vertical the entire weight of the dam must be carried to the foundation by gravity, while the distribution of the normal hydrostatic pressure between vertical cantilever and arch action will depend upon the stiffness of the dam in a vertical and horizontal direction. When the upstream face

6380-468: The area from Mesopotamia to Burma , namely, the area between the Near East and the Far East. In the late 1930s, the British established the Middle East Command , which was based in Cairo , for its military forces in the region. After that time, the term "Middle East" gained broader usage in Europe and the United States. Following World War II, for example, the Middle East Institute was founded in Washington, D.C. in 1946. The corresponding adjective

6490-497: The back of the dam through a large pipe to drive a water wheel and watermill . In the 10th century, Al-Muqaddasi described several dams in Persia. He reported that one in Ahwaz was more than 910 m (3,000 ft) long, and that it had many water-wheels raising the water into aqueducts through which it flowed into reservoirs of the city. Another one, the Band-i-Amir Dam, provided irrigation for 300 villages. Shāh Abbās Arch (Persian: طاق شاه عباس), also known as Kurit Dam ,

6600-417: The borders of India or command the approaches to India." After the series ended in 1903, The Times removed quotation marks from subsequent uses of the term. Until World War II , it was customary to refer to areas centered around Turkey and the eastern shore of the Mediterranean as the " Near East ", while the " Far East " centered on China , India and Japan . The Middle East was then defined as

6710-438: The bottom of the dam the central angle subtended by the face of the dam becomes smaller. Jones Falls Dam , in Canada, is a constant radius dam. In a constant-angle dam, also known as a variable radius dam, this subtended angle is kept constant and the variation in distance between the abutments at various levels is taken care of by varying the radii. Constant-radius dams are much less common than constant-angle dams. Parker Dam on

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6820-402: The buttress loads are heavy. In a gravity dam, the force that holds the dam in place against the push from the water is Earth's gravity pulling down on the mass of the dam. The water presses laterally (downstream) on the dam, tending to overturn the dam by rotating about its toe (a point at the bottom downstream side of the dam). The dam's weight counteracts that force, tending to rotate the dam

6930-450: The capital Amman . This gravity dam featured an originally 9-metre-high (30 ft) and 1 m-wide (3.3 ft) stone wall, supported by a 50 m-wide (160 ft) earthen rampart. The structure is dated to 3000 BC. However, the oldest continuously operational dam is Lake Homs Dam , built in Syria between 1319-1304 BC. The Ancient Egyptian Sadd-el-Kafara Dam at Wadi Al-Garawi, about 25 km (16 mi) south of Cairo ,

7040-422: The city. The masonry arch dam wall was designed by Lieutenant Percy Simpson who was influenced by the advances in dam engineering techniques made by the Royal Engineers in India . The dam cost £17,000 and was completed in 1856 as the first engineered dam built in Australia, and the second arch dam in the world built to mathematical specifications. The first such dam was opened two years earlier in France . It

7150-433: The construction of the Rideau Canal in Canada near modern-day Ottawa and built a series of curved masonry dams as part of the waterway system. In particular, the Jones Falls Dam , built by John Redpath , was completed in 1832 as the largest dam in North America and an engineering marvel. In order to keep the water in control during construction, two sluices , artificial channels for conducting water, were kept open in

7260-479: The country and are generally different from the English terms. In German the term Naher Osten (Near East) is still in common use (nowadays the term Mittlerer Osten is more and more common in press texts translated from English sources, albeit having a distinct meaning). In the four Slavic languages, Russian Ближний Восток or Blizhniy Vostok , Bulgarian Близкия Изток , Polish Bliski Wschód or Croatian Bliski istok (terms meaning Near East are

7370-455: The country is one of the region's largest and most populous. It belongs to the Indo-Iranian branch of the family of Indo-European languages . Other Western Iranic languages spoken in the region include Achomi , Daylami , Kurdish dialects, Semmani , Lurish , amongst many others. The close third-most widely spoken language, Turkish , is largely confined to Turkey, which is also one of the region's largest and most populous countries, but it

7480-469: The dam by the water reduces the lateral (horizontal) force acting on the dam. Thus, the gravitational force required by the dam is lessened, i.e., the dam does not need to be so massive. This enables thinner dams and saves resources. A barrage dam is a special kind of dam that consists of a line of large gates that can be opened or closed to control the amount of water passing the dam. The gates are set between flanking piers which are responsible for supporting

7590-533: The dam was submitted by a consortium called Six Companies, Inc. Such a large concrete structure had never been built before, and some of the techniques were unproven. The torrid summer weather and the lack of facilities near the site also presented difficulties. Nevertheless, Six Companies turned over the dam to the federal government on 1 March 1936, more than two years ahead of schedule. By 1997, there were an estimated 800,000 dams worldwide, some 40,000 of them over 15 m (49 ft) high. In 2014, scholars from

7700-605: The dam. If large enough uplift pressures are generated there is a risk of destabilizing the concrete gravity dam. On a suitable site, a gravity dam can prove to be a better alternative to other types of dams. When built on a solid foundation, the gravity dam probably represents the best-developed example of dam building. Since the fear of flood is a strong motivator in many regions, gravity dams are built in some instances where an arch dam would have been more economical. Gravity dams are classified as "solid" or "hollow" and are generally made of either concrete or masonry. The solid form

7810-407: The dam. The first was near the base of the dam on its east side. A second sluice was put in on the west side of the dam, about 20 ft (6.1 m) above the base. To make the switch from the lower to upper sluice, the outlet of Sand Lake was blocked off. Hunts Creek near the city of Parramatta , Australia , was dammed in the 1850s, to cater to the demand for water from the growing population of

7920-450: The dams' potential range and magnitude of environmental disturbances. The International Commission on Large Dams (ICOLD) defines a "large dam" as "A dam with a height of 15 m (49 ft) or greater from lowest foundation to crest or a dam between 5 m (16 ft) metres and 15 metres impounding more than 3 million cubic metres (2,400  acre⋅ft )". "Major dams" are over 150 m (490 ft) in height. The Report of

8030-652: The economy of the Western world [...] Within this contextual framework, the United States sought to divert the Arab world from Soviet influence. Throughout the 20th and 21st centuries, the region has experienced both periods of relative peace and tolerance and periods of conflict particularly between Sunnis and Shiites . Arabs constitute the largest ethnic group in the Middle East, followed by various Iranian peoples and then by Turkic peoples ( Turkish , Azeris , Syrian Turkmen , and Iraqi Turkmen ). Native ethnic groups of

8140-480: The emerging independent countries of the Islamic world . However, the usage "Near East" was retained by a variety of academic disciplines, including archaeology and ancient history . In their usage, the term describes an area identical to the term Middle East , which is not used by these disciplines (see ancient Near East ). The first official use of the term "Middle East" by the United States government

8250-512: The facility to concentrate in force if occasion arise, about Aden , India, and the Persian Gulf. Mahan's article was reprinted in The Times and followed in October by a 20-article series entitled "The Middle Eastern Question", written by Sir Ignatius Valentine Chirol . During this series, Sir Ignatius expanded the definition of Middle East to include "those regions of Asia which extend to

8360-409: The farther west countries while Middle East referred to the eastern ones, but that now they are synonymous. It instructs: Use Middle East unless Near East is used by a source in a story. Mideast is also acceptable, but Middle East is preferred. European languages have adopted terms similar to Near East and Middle East . Since these are based on a relative description, the meanings depend on

8470-786: The first decade of the 21st century to denote various countries, pertaining to the Muslim world , specifically Afghanistan , Iran , Pakistan , and Turkey . Various Central Asian countries are sometimes also included. The Middle East lies at the juncture of Africa and Eurasia and of the Indian Ocean and the Mediterranean Sea (see also: Indo-Mediterranean ). It is the birthplace and spiritual center of religions such as Christianity , Islam , Judaism , Manichaeism , Yezidi , Druze , Yarsan , and Mandeanism , and in Iran, Mithraism , Zoroastrianism , Manicheanism , and

8580-625: The first large-scale arch dams. Three pioneering arch dams were built around the British Empire in the early 19th century. Henry Russel of the Royal Engineers oversaw the construction of the Mir Alam dam in 1804 to supply water to the city of Hyderabad (it is still in use today). It had a height of 12 m (39 ft) and consisted of 21 arches of variable span. In the 1820s and 30s, Lieutenant-Colonel John By supervised

8690-636: The first was the Roman-built dam bridge in Dezful , which could raise water 50 cubits (c. 23 m) to supply the town. Also diversion dams were known. Milling dams were introduced which the Muslim engineers called the Pul-i-Bulaiti . The first was built at Shustar on the River Karun , Iran, and many of these were later built in other parts of the Islamic world . Water was conducted from

8800-534: The force of water. A fixed-crest dam is a concrete barrier across a river. Fixed-crest dams are designed to maintain depth in the channel for navigation. They pose risks to boaters who may travel over them, as they are hard to spot from the water and create induced currents that are difficult to escape. There is variability, both worldwide and within individual countries, such as in the United States, in how dams of different sizes are categorized. Dam size influences construction, repair, and removal costs and affects

8910-561: The formation of civilizations, advanced cultures formed all over the Middle East during the Stone Age . The search for agricultural lands by agriculturalists, and pastoral lands by herdsmen meant different migrations took place within the region and shaped its ethnic and demographic makeup. The Middle East is widely and most famously known as the cradle of civilization . The world's earliest civilizations, Mesopotamia ( Sumer , Akkad , Assyria and Babylonia ), ancient Egypt and Kish in

9020-526: The highest in the world, and the international oil cartel OPEC is dominated by Middle Eastern countries. During the Cold War, the Middle East was a theater of ideological struggle between the two superpowers and their allies: NATO and the United States on one side, and the Soviet Union and Warsaw Pact on the other, as they competed to influence regional allies. Besides the political reasons there

9130-522: The last century. In Iran, many religious minorities such as Christians , Baháʼís , Jews and Zoroastrians have left since the Islamic Revolution of 1979 . The Middle East is very diverse when it comes to religions , many of which originated there. Islam is the largest religion in the Middle East, but other faiths that originated there, such as Judaism and Christianity , are also well represented. Christian communities have played

9240-645: The main stream of the Kaveri River in Tamil Nadu , South India . The basic structure dates to the 2nd century AD and is considered one of the oldest water diversion or water regulating structures still in use. The purpose of the dam was to divert the waters of the Kaveri across the fertile delta region for irrigation via canals. Du Jiang Yan is the oldest surviving irrigation system in China that included

9350-573: The names of many old cities, such as Amsterdam and Rotterdam . Ancient dams were built in Mesopotamia and the Middle East for water control. The earliest known dam is the Jawa Dam in Jordan , dating to 3,000 BC. Egyptians also built dams, such as Sadd-el-Kafara Dam for flood control. In modern-day India, Dholavira had an intricate water-management system with 16 reservoirs and dams. The Great Dam of Marib in Yemen, built between 1750 and 1700 BC,

9460-404: The only appropriate ones for the region. However, some European languages do have "Middle East" equivalents, such as French Moyen-Orient , Swedish Mellanöstern , Spanish Oriente Medio or Medio Oriente , Greek is Μέση Ανατολή ( Mesi Anatoli ), and Italian Medio Oriente . Perhaps because of the political influence of the United States and Europe, and the prominence of Western press,

9570-632: The other basic dam designs which had been unknown until then. These include arch-gravity dams , arch dams , buttress dams and multiple arch buttress dams , all of which were known and employed by the 2nd century AD (see List of Roman dams ). Roman workforces also were the first to build dam bridges, such as the Bridge of Valerian in Iran. In Iran , bridge dams such as the Band-e Kaisar were used to provide hydropower through water wheels , which often powered water-raising mechanisms. One of

9680-429: The other way about its toe. The designer ensures that the dam is heavy enough that the dam's weight wins that contest. In engineering terms, that is true whenever the resultant of the forces of gravity acting on the dam and water pressure on the dam acts in a line that passes upstream of the toe of the dam. The designer tries to shape the dam so if one were to consider the part of the dam above any particular height to be

9790-580: The population of what he calls "Islamic territory" as roughly 12.5 million in 1000 – Anatolia 8 million, Syria 2 million, and Egypt 1.5 million. From the 16th century onward, the Middle East came to be dominated, once again, by two main powers: the Ottoman Empire and the Safavid dynasty . The modern Middle East began after World War I , when the Ottoman Empire, which was allied with

9900-427: The power plant, and controls flooding. The Oak Hydro-power plant ("Hidrocentrala Stejaru") is equipped with six turbines (four-27.5 MW and two-50 MW turbines ) for a total installed capacity of 210 MW. The plant generates an average of 500 GWh of electricity per year, at a capacity factor of 30%; it has produced over 20 billion MWh of electricity in the first 50 years since commissioning. This article about

10010-607: The principles behind dam design. In France, J. Augustin Tortene de Sazilly explained the mechanics of vertically faced masonry gravity dams, and Zola's dam was the first to be built on the basis of these principles. The era of large dams was initiated with the construction of the Aswan Low Dam in Egypt in 1902, a gravity masonry buttress dam on the Nile River . Following their 1882 invasion and occupation of Egypt ,

10120-439: The region as including only Egypt , Syria, Israel , Lebanon , Jordan , Iraq, Saudi Arabia , Kuwait , Bahrain , and Qatar . Since the late 20th century, scholars and journalists from the region, such as journalist Louay Khraish and historian Hassan Hanafi have criticized the use of "Middle East" as a Eurocentric and colonialist term. The Associated Press Stylebook of 2004 says that Near East formerly referred to

10230-662: The region include, in addition to Arabs, Arameans , Assyrians , Baloch , Berbers , Copts , Druze , Greek Cypriots , Jews , Kurds , Lurs , Mandaeans , Persians , Samaritans , Shabaks , Tats , and Zazas . European ethnic groups that form a diaspora in the region include Albanians , Bosniaks , Circassians (including Kabardians ), Crimean Tatars , Greeks , Franco-Levantines , Italo-Levantines , and Iraqi Turkmens . Among other migrant populations are Chinese , Filipinos , Indians , Indonesians , Pakistanis , Pashtuns , Romani , and Afro-Arabs . "Migration has always provided an important vent for labor market pressures in

10340-534: The rising influence of the United States from the 1970s onwards. In the 20th century, the region's significant stocks of crude oil gave it new strategic and economic importance. Mass production of oil began around 1945, with Saudi Arabia, Iran, Kuwait, Iraq, and the United Arab Emirates having large quantities of oil. Estimated oil reserves , especially in Saudi Arabia and Iran, are some of

10450-487: The state of New Mexico defines a jurisdictional dam as 25 feet or greater in height and storing more than 15 acre-feet or a dam that stores 50 acre-feet or greater and is six feet or more in height (section 72-5-32 NMSA), suggesting that dams that do not meet these requirements are non-jurisdictional. Most US dams, 2.41 million of a total of 2.5 million dams, are not under the jurisdiction of any public agency (i.e., they are non-jurisdictional), nor are they listed on

10560-705: The term in his article "The Persian Gulf and International Relations", published in September 1902 in the National Review , a British journal. The Middle East, if I may adopt a term which I have not seen, will some day need its Malta , as well as its Gibraltar ; it does not follow that either will be in the Persian Gulf. Naval force has the quality of mobility which carries with it the privilege of temporary absences; but it needs to find on every scene of operation established bases of refit, of supply, and in case of disaster, of security. The British Navy should have

10670-406: The water level and to prevent the sea from entering the marshlands. Such dams often marked the beginning of a town or city because it was easy to cross the river at such a place, and often influenced Dutch place names. The present Dutch capital, Amsterdam (old name Amstelredam ), started with a dam on the river Amstel in the late 12th century, and Rotterdam began with a dam on the river Rotte ,

10780-642: The water load, and are often used to control and stabilize water flow for irrigation systems. An example of this type of dam is the now-decommissioned Red Bluff Diversion Dam on the Sacramento River near Red Bluff, California . Barrages that are built at the mouths of rivers or lagoons to prevent tidal incursions or use the tidal flow for tidal power are known as tidal barrages . Embankment dams are made of compacted earth, and are of two main types: rock-fill and earth-fill. Like concrete gravity dams, embankment dams rely on their weight to hold back

10890-585: The western Middle East and until the Muslim expansion it was widely spoken there as well. Until the late 11th century, it was also the main spoken language in Asia Minor ; after that it was gradually replaced by the Turkish language as the Anatolian Turks expanded and the local Greeks were assimilated, especially in the interior. English is one of the official languages of Akrotiri and Dhekelia. It

11000-581: The world is the 305 m-high (1,001 ft) Jinping-I Dam in China . As with large dams, small dams have multiple uses, such as, but not limited to, hydropower production, flood protection, and water storage. Small dams can be particularly useful on farms to capture runoff for later use, for example, during the dry season. Small scale dams have the potential to generate benefits without displacing people as well, and small, decentralised hydroelectric dams can aid rural development in developing countries. In

11110-548: Was 102 m (335 ft) long at its base and 87 m (285 ft) wide. The structure was built around 2800 or 2600 BC as a diversion dam for flood control, but was destroyed by heavy rain during construction or shortly afterwards. During the Twelfth Dynasty in the 19th century BC, the Pharaohs Senosert III, Amenemhat III , and Amenemhat IV dug a canal 16 km (9.9 mi) long linking

11220-411: Was also the "ideological conflict" between the two systems. Moreover, as Louise Fawcett argues, among many important areas of contention, or perhaps more accurately of anxiety, were, first, the desires of the superpowers to gain strategic advantage in the region, second, the fact that the region contained some two-thirds of the world's oil reserves in a context where oil was becoming increasingly vital to

11330-715: Was an engineering wonder, and Eflatun Pinar, a Hittite dam and spring temple in Turkey, dates to the 15th and 13th centuries BC. The Kallanai Dam in South India, built in the 2nd century AD, is one of the oldest water regulating structures still in use. Roman engineers built dams with advanced techniques and materials, such as hydraulic mortar and Roman concrete, which allowed for larger structures. They introduced reservoir dams, arch-gravity dams, arch dams, buttress dams, and multiple arch buttress dams. In Iran, bridge dams were used for hydropower and water-raising mechanisms. During

11440-560: Was built. The system included 16 reservoirs, dams and various channels for collecting water and storing it. One of the engineering wonders of the ancient world was the Great Dam of Marib in Yemen . Initiated sometime between 1750 and 1700 BC, it was made of packed earth – triangular in cross-section, 580 m (1,900 ft) in length and originally 4 m (13 ft) high – running between two groups of rocks on either side, to which it

11550-740: Was in the 1957 Eisenhower Doctrine , which pertained to the Suez Crisis . Secretary of State John Foster Dulles defined the Middle East as "the area lying between and including Libya on the west and Pakistan on the east, Syria and Iraq on the North and the Arabian peninsula to the south, plus the Sudan and Ethiopia ." In 1958, the State Department explained that the terms "Near East" and "Middle East" were interchangeable, and defined

11660-434: Was linked by substantial stonework. Repairs were carried out during various periods, most importantly around 750 BC, and 250 years later the dam height was increased to 7 m (23 ft). After the end of the Kingdom of Saba , the dam fell under the control of the Ḥimyarites (c. 115 BC) who undertook further improvements, creating a structure 14 m (46 ft) high, with five spillways, two masonry-reinforced sluices,

11770-404: Was possibly the world's first concrete arch dam. Designed by Henry Charles Stanley in 1880 with an overflow spillway and a special water outlet, it was eventually heightened to 10 m (33 ft). In the latter half of the nineteenth century, significant advances in the scientific theory of masonry dam design were made. This transformed dam design from an art based on empirical methodology to

11880-461: Was the first French arch dam of the industrial era , and it was built by François Zola in the municipality of Aix-en-Provence to improve the supply of water after the 1832 cholera outbreak devastated the area. After royal approval was granted in 1844, the dam was constructed over the following decade. Its construction was carried out on the basis of the mathematical results of scientific stress analysis. The 75-miles dam near Warwick , Australia,

11990-682: Was the largest masonry dam in the world. The Hoover Dam is a massive concrete arch-gravity dam , constructed in the Black Canyon of the Colorado River , on the border between the US states of Arizona and Nevada between 1931 and 1936 during the Great Depression . In 1928, Congress authorized the project to build a dam that would control floods, provide irrigation water and produce hydroelectric power . The winning bid to build

12100-563: Was used in English to refer to the Balkans and the Ottoman Empire , while "Middle East" referred to the Caucasus , Persia , and Arabian lands, and sometimes Afghanistan , India and others. In contrast, " Far East " referred to the countries of East Asia (e.g. China , Japan , and Korea ). With the collapse of the Ottoman Empire in 1918, "Near East" largely fell out of common use in English, while "Middle East" came to be applied to

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