141-481: The Mormon Flat Dam is a dam on the Salt River located Northeast of Phoenix, Arizona . The dam is 380 feet long, 224 feet high and was built between 1923 and 1925. It is named after nearby Mormon Flat, a place where Latter-day Saints (Mormon) settlers from Utah stopped to camp. There are two hydroelectric generating units in the dam; rated at 10,000 and 50,000 kW. The dam forms Canyon Lake as it slows
282-639: A ceramic glaze known as faience , which was used well into the Roman Period to decorate cups, amulets, and figurines. During the last predynastic phase, the Naqada culture began using written symbols that eventually were developed into a full system of hieroglyphs for writing the ancient Egyptian language. The Early Dynastic Period was approximately contemporary to the early Sumerian - Akkadian civilization of Mesopotamia and of ancient Elam . The third-century BC Egyptian priest Manetho grouped
423-469: A corvée system. Artists and craftsmen were of higher status than farmers, but they were also under state control, working in the shops attached to the temples and paid directly from the state treasury. Scribes and officials formed the upper class in ancient Egypt, known as the "white kilt class" in reference to the bleached linen garments that served as a mark of their rank. The upper class prominently displayed their social status in art and literature. Below
564-417: A nomarch , who was accountable to the vizier for his jurisdiction. The temples formed the backbone of the economy. Not only were they places of worship , but were also responsible for collecting and storing the kingdom's wealth in a system of granaries and treasuries administered by overseers , who redistributed grain and goods. Much of the economy was centrally organized and strictly controlled. Although
705-444: A balanced relationship between people and animals was an essential element of the cosmic order; thus humans, animals and plants were believed to be members of a single whole. Animals, both domesticated and wild , were therefore a critical source of spirituality, companionship, and sustenance to the ancient Egyptians. Cattle were the most important livestock; the administration collected taxes on livestock in regular censuses , and
846-401: 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
987-607: A brief but spirited resurgence in the economy and culture, but in 525 BC, the Persian Empire, led by Cambyses II , began its conquest of Egypt, eventually defeating the pharaoh Psamtik III at the Battle of Pelusium . Cambyses II then assumed the formal title of pharaoh, but ruled Egypt from Iran, leaving Egypt under the control of a satrap . A few revolts against the Persians marked the 5th century BC, but Egypt
1128-710: A confident, eloquent style. The relief and portrait sculpture of the period captured subtle, individual details that reached new heights of technical sophistication. The last great ruler of the Middle Kingdom, Amenemhat III , allowed Semitic -speaking Canaanite settlers from the Near East into the Delta region to provide a sufficient labor force for his especially active mining and building campaigns. These ambitious building and mining activities, however, combined with severe Nile floods later in his reign, strained
1269-542: A cornerstone in the history of human civilization. Nomadic modern human hunter-gatherers began living in the Nile valley through the end of the Middle Pleistocene some 120,000 years ago. By the late Paleolithic period, the arid climate of Northern Africa had become increasingly hot and dry, forcing the populations of the area to concentrate along the river region. In Predynastic and Early Dynastic times,
1410-544: 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,
1551-499: 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
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#17327726272341692-493: 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
1833-478: 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
1974-576: A large-scale building campaign to promote the god Amun , whose growing cult was based in Karnak . They also constructed monuments to glorify their own achievements, both real and imagined. The Karnak temple is the largest Egyptian temple ever built. Around 1350 BC, the stability of the New Kingdom was threatened when Amenhotep IV ascended the throne and instituted a series of radical and chaotic reforms. Changing his name to Akhenaten , he touted
2115-511: 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
2256-509: 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
2397-576: A period of economic and cultural renaissance known as the Middle Kingdom . The kings of the Middle Kingdom restored the country's stability and prosperity, thereby stimulating a resurgence of art, literature, and monumental building projects. Mentuhotep II and his Eleventh Dynasty successors ruled from Thebes, but the vizier Amenemhat I , upon assuming the kingship at the beginning of the Twelfth Dynasty around 1985 BC, shifted
2538-508: A piece of papyrus or an ostracon . A combination of favorable geographical features contributed to the success of ancient Egyptian culture, the most important of which was the rich fertile soil resulting from annual inundations of the Nile River. The ancient Egyptians were thus able to produce an abundance of food, allowing the population to devote more time and resources to cultural, technological, and artistic pursuits. Land management
2679-649: 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
2820-689: A queen who established herself as pharaoh, launched many building projects, including the restoration of temples damaged by the Hyksos, and sent trading expeditions to Punt and the Sinai. When Tuthmosis III died in 1425 BC, Egypt had an empire extending from Niya in north west Syria to the Fourth Cataract of the Nile in Nubia , cementing loyalties and opening access to critical imports such as bronze and wood . The New Kingdom pharaohs began
2961-608: A rival dynasty in the delta arose in Leontopolis , and Kushites threatened from the south. Around 727 BC the Kushite king Piye invaded northward, seizing control of Thebes and eventually the Delta, which established the 25th Dynasty . During the 25th Dynasty, Pharaoh Taharqa created an empire nearly as large as the New Kingdom 's. Twenty-fifth Dynasty pharaohs built, or restored, temples and monuments throughout
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#17327726272343102-662: A series of vassals who became known as the Saite kings of the Twenty-Sixth Dynasty . By 653 BC, the Saite king Psamtik I was able to oust the Assyrians with the help of Greek mercenaries, who were recruited to form Egypt's first navy . Greek influence expanded greatly as the city-state of Naucratis became the home of Greeks in the Nile Delta. The Saite kings based in the new capital of Sais witnessed
3243-566: 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
3384-408: 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
3525-424: 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
3666-480: 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
3807-471: 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
3948-399: 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
4089-590: 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
4230-583: The Amarna Period . Around 1279 BC, Ramesses II , also known as Ramesses the Great, ascended the throne, and went on to build more temples, erect more statues and obelisks, and sire more children than any other pharaoh in history. A bold military leader, Ramesses II led his army against the Hittites in the Battle of Kadesh (in modern Syria ) and, after fighting to a stalemate, finally agreed to
4371-508: The Egyptian climate was much less arid than it is today . Large regions of Egypt were covered in treed savanna and traversed by herds of grazing ungulates . Foliage and fauna were far more prolific in all environs, and the Nile region supported large populations of waterfowl . Hunting would have been common for Egyptians, and this is also the period when many animals were first domesticated . By about 5500 BC , small tribes living in
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4512-657: 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
4653-501: The Great Kenbet , over which the vizier or pharaoh presided. Plaintiffs and defendants were expected to represent themselves and were required to swear an oath that they had told the truth. In some cases, the state took on both the role of prosecutor and judge, and it could torture the accused with beatings to obtain a confession and the names of any co-conspirators. Whether the charges were trivial or serious, court scribes documented
4794-579: 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
4935-613: The Macedonians under Alexander the Great . The Greek Ptolemaic Kingdom , formed in the aftermath of Alexander's death, ruled until 30 BC, when, under Cleopatra , it fell to the Roman Empire and became a Roman province . Egypt remained under Roman control until 642 AD, when it was conquered by the Rashidun Caliphate . The success of ancient Egyptian civilization came partly from its ability to adapt to
5076-971: The Mouseion . The Lighthouse of Alexandria lit the way for the many ships that kept trade flowing through the city—as the Ptolemies made commerce and revenue-generating enterprises, such as papyrus manufacturing, their top priority. Hellenistic culture did not supplant native Egyptian culture, as the Ptolemies supported time-honored traditions in an effort to secure the loyalty of the populace. They built new temples in Egyptian style, supported traditional cults, and portrayed themselves as pharaohs. Some traditions merged, as Greek and Egyptian gods were syncretized into composite deities, such as Serapis , and classical Greek forms of sculpture influenced traditional Egyptian motifs. Despite their efforts to appease
5217-541: The National Inventory of Dams (NID). Ancient Egypt Ancient Egypt was a civilization of ancient Northeast Africa . It was concentrated along the lower reaches of the Nile River , situated within the contemporary territory of modern-day Egypt . Ancient Egyptian civilization followed prehistoric Egypt and coalesced around 3100 BC (according to conventional Egyptian chronology ) with
5358-496: The Near East . The New Kingdom pharaohs established a period of unprecedented prosperity by securing their borders and strengthening diplomatic ties with their neighbours, including the Mitanni Empire, Assyria , and Canaan . Military campaigns waged under Tuthmosis I and his grandson Tuthmosis III extended the influence of the pharaohs to the largest empire Egypt had ever seen. Between their reigns, Hatshepsut ,
5499-772: The New Kingdom of the Late Bronze Age . Ancient Egypt reached the pinnacle of its power during the New Kingdom, ruling much of Nubia and a sizable portion of the Levant . After this period, it entered an era of slow decline. During the course of its history, ancient Egypt was invaded or conquered by a number of foreign powers, including the Hyksos , the Nubians , the Assyrians , the Achaemenid Persians , and
5640-534: The Nile . They also traded with Nubia to the south, the oases of the western desert to the west, and the cultures of the eastern Mediterranean and Near East to the east. The Naqada culture manufactured a diverse selection of material goods, reflective of the increasing power and wealth of the elite, as well as societal personal-use items, which included combs, small statuary, painted pottery, high quality decorative stone vases , cosmetic palettes , and jewelry made of gold, lapis, and ivory. They also developed
5781-467: The Nubians to the south of Egypt, but failed to defeat the Hyksos. That task fell to Kamose's successor, Ahmose I , who successfully waged a series of campaigns that permanently eradicated the Hyksos' presence in Egypt. He established a new dynasty and, in the New Kingdom that followed, the military became a central priority for the kings, who sought to expand Egypt's borders and attempted to gain mastery of
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5922-606: The Persians and was welcomed by the Egyptians as a deliverer. The administration established by Alexander's successors, the Macedonian Ptolemaic Kingdom , was based on an Egyptian model and based in the new capital city of Alexandria . The city showcased the power and prestige of Hellenistic rule, and became a centre of learning and culture, that included the famous Library of Alexandria as part of
6063-619: The Thirtieth , proved to be the last native royal house of ancient Egypt, ending with the kingship of Nectanebo II . A brief restoration of Persian rule, sometimes known as the Thirty-First Dynasty , began in 343 BC, but shortly after, in 332 BC, the Persian ruler Mazaces handed Egypt over to Alexander the Great without a fight. In 332 BC, Alexander the Great conquered Egypt with little resistance from
6204-645: 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
6345-549: The Wadi Natrun for mummification , which also provided the gypsum needed to make plaster. Ore-bearing rock formations were found in distant, inhospitable wadis in the Eastern Desert and the Sinai, requiring large, state-controlled expeditions to obtain natural resources found there. There were extensive gold mines in Nubia , and one of the first maps known is of a gold mine in this region. The Wadi Hammamat
6486-451: The chaff from the grain, and the grain was then ground into flour, brewed to make beer, or stored for later use. The ancient Egyptians cultivated emmer and barley , and several other cereal grains, all of which were used to make the two main food staples of bread and beer. Flax plants, uprooted before they started flowering, were grown for the fibers of their stems. These fibers were split along their length and spun into thread, which
6627-581: The composite bow and the horse-drawn chariot . After retreating south, the native Theban kings found themselves trapped between the Canaanite Hyksos ruling the north and the Hyksos' Nubian allies, the Kushites , to the south. After years of vassalage, Thebes gathered enough strength to challenge the Hyksos in a conflict that lasted more than 30 years, until 1555 BC. The kings Seqenenre Tao II and Kamose were ultimately able to defeat
6768-458: The earliest known peace treaty , made with the Hittites . Ancient Egypt has left a lasting legacy. Its art and architecture were widely copied, and its antiquities were carried off to be studied, admired or coveted in the far corners of the world. Its monumental ruins have inspired the imaginations of travelers and writers for millennia. A newfound respect for antiquities and excavations in
6909-523: The vizier and his court for redress. Although slaves were mostly used as indentured servants, they were able to buy and sell their servitude, work their way to freedom or nobility, and were usually treated by doctors in the workplace. Both men and women had the right to own and sell property, make contracts, marry and divorce, receive inheritance, and pursue legal disputes in court. Married couples could own property jointly and protect themselves from divorce by agreeing to marriage contracts, which stipulated
7050-572: The Assyrians. The effects of external threats were exacerbated by internal problems such as corruption, tomb robbery, and civil unrest . After regaining their power, the high priests at the temple of Amun in Thebes accumulated vast tracts of land and wealth, and their expanded power splintered the country during the Third Intermediate Period. Following the death of Ramesses XI in 1078 BC, Smendes assumed authority over
7191-544: 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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#17327726272347332-476: The Christian emperor Theodosius introduced legislation that banned pagan rites and closed temples. Alexandria became the scene of great anti-pagan riots with public and private religious imagery destroyed. As a consequence, Egypt's native religious culture was continually in decline. While the native population continued to speak their language , the ability to read hieroglyphic writing slowly disappeared as
7473-520: 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
7614-680: 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
7755-435: The Delta, seized control of Egypt and established their capital at Avaris , forcing the former central government to retreat to Thebes . The king was treated as a vassal and expected to pay tribute. The Hyksos ('foreign rulers') retained Egyptian models of government and identified as kings, thereby integrating Egyptian elements into their culture. They and other invaders introduced new tools of warfare into Egypt, most notably
7896-453: The Egyptians, the Ptolemies were challenged by native rebellion, bitter family rivalries, and the powerful mob of Alexandria that formed after the death of Ptolemy IV . In addition, as Rome relied more heavily on imports of grain from Egypt, the Romans took great interest in the political situation in the country. Continued Egyptian revolts, ambitious politicians, and powerful opponents from
8037-504: The Greeks towards the Egyptians, some traditions such as mummification and worship of the traditional gods continued. The art of mummy portraiture flourished, and some Roman emperors had themselves depicted as pharaohs, though not to the extent that the Ptolemies had. The former lived outside Egypt and did not perform the ceremonial functions of Egyptian kingship. Local administration became Roman in style and closed to native Egyptians. From
8178-545: The Late Period, the worship of the gods in their animal form was extremely popular, such as the cat goddess Bastet and the ibis god Thoth , and these animals were kept in large numbers for the purpose of ritual sacrifice. Egypt is rich in building and decorative stone, copper and lead ores, gold, and semiprecious stones. These natural resources allowed the ancient Egyptians to build monuments, sculpt statues, make tools, and fashion jewelry . Embalmers used salts from
8319-452: The Late Period. There is also evidence to suggest that elephants were briefly used in the Late Period but largely abandoned due to lack of grazing land. Cats , dogs, and monkeys were common family pets, while more exotic pets imported from the heart of Africa, such as Sub-Saharan African lions , were reserved for royalty. Herodotus observed that the Egyptians were the only people to keep their animals with them in their houses. During
8460-662: 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
8601-417: The Near East made this situation unstable, leading Rome to send forces to secure the country as a province of its empire. Egypt became a province of the Roman Empire in 30 BC, following the defeat of Mark Antony and Ptolemaic Queen Cleopatra VII by Octavian (later Emperor Augustus) in the Battle of Actium . The Romans relied heavily on grain shipments from Egypt, and the Roman army , under
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#17327726272348742-451: The Nile valley had developed into a series of cultures demonstrating firm control of agriculture and animal husbandry , and identifiable by their pottery and personal items, such as combs, bracelets, and beads. The largest of these early cultures in upper (Southern) Egypt was the Badarian culture , which probably originated in the Western Desert ; it was known for its high-quality ceramics, stone tools , and its use of copper. The Badari
8883-419: The Nile valley, including at Memphis, Karnak, Kawa, and Jebel Barkal. During this period, the Nile valley saw the first widespread construction of pyramids (many in modern Sudan) since the Middle Kingdom. Egypt's far-reaching prestige declined considerably toward the end of the Third Intermediate Period. Its foreign allies had fallen under the Assyrian sphere of influence, and by 700 BC war between
9024-443: The Old Kingdom, and provided both honey and wax. The ancient Egyptians used donkeys and oxen as beasts of burden , and they were responsible for plowing the fields and trampling seed into the soil. The slaughter of a fattened ox was also a central part of an offering ritual. Horses were introduced by the Hyksos in the Second Intermediate Period . Camels, although known from the New Kingdom, were not used as beasts of burden until
9165-405: The Old Kingdom. Under the direction of the vizier , state officials collected taxes, coordinated irrigation projects to improve crop yield , drafted peasants to work on construction projects, and established a justice system to maintain peace and order. With the rising importance of central administration in Egypt, a new class of educated scribes and officials arose who were granted estates by
9306-460: The Ruler ", to defend against foreign attack. With the kings having secured the country militarily and politically and with vast agricultural and mineral wealth at their disposal, the nation's population, arts, and religion flourished. In contrast to elitist Old Kingdom attitudes towards the gods, the Middle Kingdom displayed an increase in expressions of personal piety. Middle Kingdom literature featured sophisticated themes and characters written in
9447-437: 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
9588-457: 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
9729-499: The administration, aside from the royal high priestesses, apparently served only secondary roles in the temples (not much data for many dynasties), and were not so probably to be as educated as men. The head of the legal system was officially the pharaoh, who was responsible for enacting laws, delivering justice, and maintaining law and order, a concept the ancient Egyptians referred to as Ma'at . Although no legal codes from ancient Egypt survive, court documents show that Egyptian law
9870-507: The ancient Egyptians did not use coinage until the Late period , they did use a type of money-barter system, with standard sacks of grain and the deben , a weight of roughly 91 grams (3 oz) of copper or silver, forming a common denominator. Workers were paid in grain; a simple laborer might earn 5 + 1 ⁄ 2 sacks (200 kg or 400 lb) of grain per month, while a foreman might earn 7 + 1 ⁄ 2 sacks (250 kg or 550 lb). Prices were fixed across
10011-407: The ancient Egyptians include the quarrying , surveying , and construction techniques that supported the building of monumental pyramids , temples , and obelisks ; a system of mathematics , a practical and effective system of medicine , irrigation systems, and agricultural production techniques, the first known planked boats, Egyptian faience and glass technology, new forms of literature , and
10152-403: 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
10293-666: 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 ,
10434-491: 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
10575-402: 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
10716-501: 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 ,
10857-646: 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
10998-410: The complaint, testimony, and verdict of the case for future reference. Punishment for minor crimes involved either imposition of fines, beatings, facial mutilation, or exile, depending on the severity of the offense. Serious crimes such as murder and tomb robbery were punished by execution, carried out by decapitation, drowning, or impaling the criminal on a stake. Punishment could also be extended to
11139-419: The conditions of the Nile River valley for agriculture . The predictable flooding and controlled irrigation of the fertile valley produced surplus crops, which supported a more dense population, and social development and culture. With resources to spare, the administration sponsored mineral exploitation of the valley and surrounding desert regions, the early development of an independent writing system ,
11280-671: 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
11421-452: The control of a prefect appointed by the emperor, quelled rebellions, strictly enforced the collection of heavy taxes, and prevented attacks by bandits, which had become a notorious problem during the period. Alexandria became an increasingly important center on the trade route with the orient, as exotic luxuries were in high demand in Rome. Although the Romans had a more hostile attitude than
11562-401: The country and recorded in lists to facilitate trading; for example a shirt cost five copper deben, while a cow cost 140 deben. Grain could be traded for other goods, according to the fixed price list. During the fifth century BC coined money was introduced into Egypt from abroad. At first the coins were used as standardized pieces of precious metal rather than true money, but in
11703-403: The country's economy. Regional governors could not rely on the king for help in times of crisis, and the ensuing food shortages and political disputes escalated into famines and small-scale civil wars. Yet despite difficult problems, local leaders, owing no tribute to the king, used their new-found independence to establish a thriving culture in the provinces. Once in control of their own resources,
11844-421: The criminal's family. Beginning in the New Kingdom, oracles played a major role in the legal system, dispensing justice in both civil and criminal cases. The procedure was to ask the god a "yes" or "no" question concerning the right or wrong of an issue. The god, carried by a number of priests, rendered judgement by choosing one or the other, moving forward or backward, or pointing to one of the answers written on
11985-469: 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
12126-533: 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
12267-605: 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
12408-407: 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
12549-450: 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
12690-411: The early modern period by Europeans and Egyptians has led to the scientific investigation of Egyptian civilization and a greater appreciation of its cultural legacy. The Nile has been the lifeline of its region for much of human history. The fertile floodplain of the Nile gave humans the opportunity to develop a settled agricultural economy and a more sophisticated, centralized society that became
12831-572: The economy and precipitated the slow decline into the Second Intermediate Period during the later Thirteenth and Fourteenth dynasties. During this decline, the Canaanite settlers began to assume greater control of the Delta region, eventually coming to power in Egypt as the Hyksos . Around 1785 BC, as the power of the Middle Kingdom kings weakened, a Western Asian people called the Hyksos , who had already settled in
12972-424: The fertile delta region, as well as the lucrative and critical trade routes to the Levant . The increasing power and wealth of the kings during the early dynastic period was reflected in their elaborate mastaba tombs and mortuary cult structures at Abydos, which were used to celebrate the deified king after his death. The strong institution of kingship developed by the kings served to legitimize state control over
13113-524: The financial obligations of the husband to his wife and children should the marriage end. Compared with their counterparts in ancient Greece, Rome, and even more modern places around the world, ancient Egyptian women had a greater range of personal choices, legal rights, and opportunities for achievement. Women such as Hatshepsut and Cleopatra VII even became pharaohs, while others wielded power as Divine Wives of Amun . Despite these freedoms, ancient Egyptian women did not often take part in official roles in
13254-561: 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
13395-613: The first recorded peace treaty , around 1258 BC. Egypt's wealth, however, made it a tempting target for invasion, particularly by the Libyan Berbers to the west, and the Sea Peoples , a conjectured confederation of seafarers from the Aegean Sea . Initially, the military was able to repel these invasions, but Egypt eventually lost control of its remaining territories in southern Canaan , much of it falling to
13536-742: 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
13677-427: The floodwaters had receded, the growing season lasted from October to February. Farmers plowed and planted seeds in the fields, which were irrigated with ditches and canals. Egypt received little rainfall, so farmers relied on the Nile to water their crops. From March to May, farmers used sickles to harvest their crops, which were then threshed with a flail to separate the straw from the grain. Winnowing removed
13818-417: The following centuries international traders came to rely on coinage. Egyptian society was highly stratified, and social status was expressly displayed. Farmers made up the bulk of the population, but agricultural produce was owned directly by the state, temple, or noble family that owned the land. Farmers were also subject to a labor tax and were required to work on irrigation or construction projects in
13959-534: 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
14100-412: The government, who relied on a bureaucracy of officials to manage his affairs. In charge of the administration was his second in command, the vizier , who acted as the king's representative and coordinated land surveys, the treasury, building projects, the legal system, and the archives . At a regional level, the country was divided into as many as 42 administrative regions called nomes each governed by
14241-411: The king in payment for their services. Kings also made land grants to their mortuary cults and local temples , to ensure that these institutions had the resources to worship the king after his death. Scholars believe that five centuries of these practices slowly eroded the economic vitality of Egypt, and that the economy could no longer afford to support a large centralized administration. As the power of
14382-593: The kingdom's capital to the city of Itjtawy , located in Faiyum . From Itjtawy, the kings of the Twelfth Dynasty undertook a far-sighted land reclamation and irrigation scheme to increase agricultural output in the region. Moreover, the military reconquered territory in Nubia that was rich in quarries and gold mines, while laborers built a defensive structure in the Eastern Delta, called the " Walls of
14523-588: The kings diminished, regional governors called nomarchs began to challenge the supremacy of the office of king. This, coupled with severe droughts between 2200 and 2150 BC, is believed to have caused the country to enter the 140-year period of famine and strife known as the First Intermediate Period. After Egypt's central government collapsed at the end of the Old Kingdom, the administration could no longer support or stabilize
14664-566: The land, labor, and resources that were essential to the survival and growth of ancient Egyptian civilization. Major advances in architecture, art, and technology were made during the Old Kingdom , fueled by the increased agricultural productivity and resulting population growth, made possible by a well-developed central administration. Some of ancient Egypt's crowning achievements, the Giza pyramids and Great Sphinx , were constructed during
14805-497: The long line of kings from Menes to his own time into 30 dynasties, a system still used today. He began his official history with the king named "Meni" (or Menes in Greek), who was believed to have united the two kingdoms of Upper and Lower Egypt . The transition to a unified state happened more gradually than ancient Egyptian writers represented, and there is no contemporary record of Menes. Some scholars now believe, however, that
14946-645: 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
15087-464: The mid-first century AD, Christianity took root in Egypt and it was originally seen as another cult that could be accepted. However, it was an uncompromising religion that sought to win converts from the pagan Egyptian and Greco-Roman religions and threatened popular religious traditions. This led to the persecution of converts to Christianity, culminating in the great purges of Diocletian starting in 303, but eventually Christianity won out. In 391,
15228-528: The mythical Menes may have been the king Narmer , who is depicted wearing royal regalia on the ceremonial Narmer Palette, in a symbolic act of unification. In the Early Dynastic Period, which began about 3000 BC, the first of the Dynastic kings solidified control over lower Egypt by establishing a capital at Memphis , from which he could control the labor force and agriculture of
15369-633: 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,
15510-405: The nobility were the priests, physicians, and engineers with specialized training in their field. It is unclear whether slavery as understood today existed in ancient Egypt; there is difference of opinions among authors. The ancient Egyptians viewed men and women, including people from all social classes, as essentially equal under the law, and even the lowliest peasant was entitled to petition
15651-682: The north, while a rival clan based in Thebes , the Intef family , took control of Upper Egypt in the south. As the Intefs grew in power and expanded their control northward, a clash between the two rival dynasties became inevitable. Around 2055 BC the northern Theban forces under Nebhepetre Mentuhotep II finally defeated the Herakleopolitan rulers, reuniting the Two Lands. They inaugurated
15792-676: The northern part of Egypt, ruling from the city of Tanis . The south was effectively controlled by the High Priests of Amun at Thebes , who recognized Smendes in name only. During this time, Libyans had been settling in the western delta, and chieftains of these settlers began increasing their autonomy. Libyan princes took control of the delta under Shoshenq I in 945 BC, founding the so-called Libyan or Bubastite dynasty that would rule for some 200 years. Shoshenq also gained control of southern Egypt by placing his family members in important priestly positions. Libyan control began to erode as
15933-462: The organization of collective construction and agricultural projects, trade with surrounding regions, and a military intended to assert Egyptian dominance. Motivating and organizing these activities was a bureaucracy of elite scribes , religious leaders, and administrators under the control of a pharaoh , who ensured the cooperation and unity of the Egyptian people in the context of an elaborate system of religious beliefs . The many achievements of
16074-683: 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
16215-429: 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
16356-563: The passage of the Salt River . The dam was listed on the National Register of Historic Places in 2017. [REDACTED] Media related to Mormon Flat Dam at Wikimedia Commons 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
16497-557: The political unification of Upper and Lower Egypt under pharaoh or king Menes (often identified with Narmer ). The history of ancient Egypt unfolded as a series of stable kingdoms interspersed by periods of relative instability known as "Intermediate Periods". The various kingdoms fall into one of three categories: the Old Kingdom of the Early Bronze Age , the Middle Kingdom of the Middle Bronze Age , or
16638-528: The previously obscure sun deity Aten as the supreme deity , suppressed the worship of most other deities, and moved the capital to the new city of Akhetaten (modern-day Amarna ). He was devoted to his new religion and artistic style . After his death, the cult of the Aten was quickly abandoned and the traditional religious order restored. The subsequent pharaohs, Tutankhamun , Ay , and Horemheb , worked to erase all mention of Akhenaten's heresy, now known as
16779-549: 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 ,
16920-621: The provinces became economically richer—which was demonstrated by larger and better burials among all social classes. In bursts of creativity, provincial artisans adopted and adapted cultural motifs formerly restricted to the royalty of the Old Kingdom, and scribes developed literary styles that expressed the optimism and originality of the period. Free from their loyalties to the king, local rulers began competing with each other for territorial control and political power . By 2160 BC, rulers in Herakleopolis controlled Lower Egypt in
17061-718: The role of the Egyptian temple priests and priestesses diminished. The temples themselves were sometimes converted to churches or abandoned to the desert. In the fourth century, as the Roman Empire divided, Egypt found itself in the Eastern Empire with its capital at Constantinople . In the waning years of the Empire, Egypt fell to the Sasanian Persian army in the Sasanian conquest of Egypt (618–628). It
17202-402: The size of a herd reflected the prestige and importance of the estate or temple that owned them. In addition to cattle, the ancient Egyptians kept sheep, goats, and pigs. Poultry , such as ducks, geese, and pigeons, were captured in nets and bred on farms, where they were force-fed with dough to fatten them. The Nile provided a plentiful source of fish . Bees were also domesticated from at least
17343-487: 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
17484-549: The two states became inevitable. Between 671 and 667 BC the Assyrians began the Assyrian conquest of Egypt . The reigns of both Taharqa and his successor, Tanutamun , were filled with constant conflict with the Assyrians, against whom Egypt enjoyed several victories. Ultimately, the Assyrians pushed the Kushites back into Nubia, occupied Memphis, and sacked the temples of Thebes . The Assyrians left control of Egypt to
17625-406: 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 ,
17766-642: 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
17907-581: 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
18048-484: 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
18189-542: Was also the beginning of trade with Mesopotamia , which continued into the early dynastic period and beyond. Over a period of about 1,000 years, the Naqada culture developed from a few small farming communities into a powerful civilization whose leaders were in complete control of the people and resources of the Nile valley. Establishing a power center at Nekhen (in Greek, Hierakonpolis), and later at Abydos , Naqada III leaders expanded their control of Egypt northwards along
18330-715: 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
18471-423: Was based on a common-sense view of right and wrong that emphasized reaching agreements and resolving conflicts rather than strictly adhering to a complicated set of statutes. Local councils of elders, known as Kenbet in the New Kingdom, were responsible for ruling in court cases involving small claims and minor disputes. More serious cases involving murder, major land transactions, and tomb robbery were referred to
18612-560: 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
18753-421: Was crucial in ancient Egypt because taxes were assessed based on the amount of land a person owned. Farming in Egypt was dependent on the cycle of the Nile River. The Egyptians recognized three seasons: Akhet (flooding), Peret (planting), and Shemu (harvesting). The flooding season lasted from June to September, depositing on the river's banks a layer of mineral-rich silt ideal for growing crops. After
18894-541: Was followed by the Naqada culture : the Naqada I ( Amratian ), the Naqada II ( Gerzeh ), and Naqada III ( Semainean ). These brought a number of technological improvements. As early as the Naqada I Period, predynastic Egyptians imported obsidian from Ethiopia , used to shape blades and other objects from flakes . Mutual trade with the Levant was established during Naqada II ( c. 3600–3350 BC ); this period
19035-488: 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,
19176-577: Was never able to overthrow the Persians until the end of the century. Following its annexation by Persia, Egypt was joined with Cyprus and Phoenicia in the sixth satrapy of the Achaemenid Persian Empire . This first period of Persian rule over Egypt, also known as the Twenty-Seventh Dynasty , ended in 402 BC, when Egypt regained independence under a series of native dynasties. The last of these dynasties,
19317-404: 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
19458-461: 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,
19599-682: 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
19740-476: Was then recaptured by the Byzantine emperor Heraclius (629–639), and was finally captured by Muslim Rashidun army in 639–641, marking the end of both Byzantine rule and of the period typically considered Ancient Egypt. The pharaoh was the absolute monarch of the country and, at least in theory, wielded complete control of the land and its resources. The king was the supreme military commander and head of
19881-420: Was used to weave sheets of linen and to make clothing. Papyrus growing on the banks of the Nile River was used to make paper. Vegetables and fruits were grown in garden plots, close to habitations and on higher ground, and had to be watered by hand. Vegetables included leeks, garlic, melons, squashes, pulses, lettuce, and other crops, in addition to grapes that were made into wine. The Egyptians believed that
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