89-531: Lago di Luzzone is a reservoir in Ticino , Switzerland . The reservoir has a volume of 108 million m³ and a surface area of 1.27 km (0.49 sq mi). It is located in the upper Blenio valley, in the municipalities of Ghirone and Aquila . The reservoir is surrounded by peaks of the Adula Alps , some of which rise more than 3,000 meters, and is located at a height of 1,606 meters above sea level. The highest
178-436: A Top Gear episode showed an occupied car doing a bungee jump . One wall of the dam currently features the world's highest artificial climbing wall . A German manufacturer of climbing holds installed a line of over 650 artificial holds and bolts. The course covers a vertical distance of 165 meters, going from the base of the dam to the top. The climb must be done as a multi-pitch bolted sport climbing route. Furthermore,
267-639: A Polish archaeologist, Kazimierz Michałowski , from the Polish Centre of Mediterranean Archaeology University of Warsaw . The Abu Simbel complex, and other relocated temples from Nubian sites such as Philae , Amada , Wadi es-Sebua , are part of the UNESCO World Heritage Site known as the Nubian Monuments. During his reign, Ramesses II embarked on an extensive building program throughout Egypt and Nubia , which Egypt controlled. Nubia
356-537: A block for migrating fish, trapping them in one area, producing food and a habitat for various water-birds. They can also flood various ecosystems on land and may cause extinctions. Creating reservoirs can alter the natural biogeochemical cycle of mercury . After a reservoir's initial formation, there is a large increase in the production of toxic methylmercury (MeHg) via microbial methylation in flooded soils and peat. MeHg levels have also been found to increase in zooplankton and in fish. Dams can severely reduce
445-791: A chain up the valley. Coastal reservoirs are fresh water storage reservoirs located on the sea coast near a river mouth to store the flood water of a river. As the land-based reservoir construction is fraught with substantial land submergence, coastal reservoirs are preferred economically and technically since they do not use scarce land area. Many coastal reservoirs were constructed in Asia and Europe. Saemanguem in South Korea, Marina Barrage in Singapore, Qingcaosha in China, and Plover Cove in Hong Kong are
534-636: A conventional oil-fired thermal generation plant. For instance, In 1990, the impoundment behind the Balbina Dam in Brazil (inaugurated in 1987) had over 20 times the impact on global warming than would generating the same power from fossil fuels, due to the large area flooded per unit of electricity generated. Another study published in the Global Biogeochemical Cycles also found that newly flooded reservoirs released more carbon dioxide and methane than
623-425: A distance of about two hundred yards from the temple; they stand in a deep recess, excavated in the mountain; but it is greatly to be regretted, that they are now almost entirely buried beneath the sands, which are blown down here in torrents. The entire head, and part of the breast and arms of one of the statues are yet above the surface; of the one next to it scarcely any part is visible, the head being broken off, and
712-529: A drop of water seep into the ocean without benefiting mankind." He created the reservoir named Parakrama Samudra ("sea of King Parakrama"). Vast artificial reservoirs were also built by various ancient kingdoms in Bengal, Assam, and Cambodia. Many dammed river reservoirs and most bank-side reservoirs are used to provide the raw water feed to a water treatment plant which delivers drinking water through water mains. The reservoir does not merely hold water until it
801-525: A few such coastal reservoirs. Where water is pumped or siphoned from a river of variable quality or size, bank-side reservoirs may be built to store the water. Such reservoirs are usually formed partly by excavation and partly by building a complete encircling bund or embankment , which may exceed 6 km (4 miles) in circumference. Both the floor of the reservoir and the bund must have an impermeable lining or core: initially these were often made of puddled clay , but this has generally been superseded by
890-455: A high-level reservoir is filled with water using high-performance electric pumps at times when electricity demand is low, and then uses this stored water to generate electricity by releasing the stored water into a low-level reservoir when electricity demand is high. Such systems are called pump-storage schemes. Reservoirs can be used in a number of ways to control how water flows through downstream waterways: Reservoirs can be used to balance
979-570: A loss in both quantity and quality of water necessary for maintaining ecological balance and pose a risk of increasing severity and duration of droughts due to climate change. In summary, they consider it a misadaptation to climate change. Proponents of reservoirs or substitution reserves, on the other hand, see them as a solution for sustainable agriculture while waiting for a truly durable agricultural model. Without such reserves, they fear that unsustainable imported irrigation will be inevitable. They believe that these reservoirs should be accompanied by
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#17330848420741068-419: A narrow valley or canyon may cover relatively little vegetation, while one situated on a plain may flood a great deal of vegetation. The site may be cleared of vegetation first or simply flooded. Tropical flooding can produce far more greenhouse gases than in temperate regions. The following table indicates reservoir emissions in milligrams per square meter per day for different bodies of water. Depending upon
1157-592: A reservoir is called the "conservation pool". In the United Kingdom, "top water level" describes the reservoir full state, while "fully drawn down" describes the minimum retained volume. There is a wide variety of software for modelling reservoirs, from the specialist Dam Safety Program Management Tools (DSPMT) to the relatively simple WAFLEX , to integrated models like the Water Evaluation And Planning system (WEAP) that place reservoir operations in
1246-720: A river valley, with the potential to wash away towns and villages and cause considerable loss of life, such as the devastation following the failure of containment at Llyn Eigiau which killed 17 people. (see also List of dam failures ) A notable case of reservoirs being used as an instrument of war involved the British Royal Air Force Dambusters raid on Germany in World War II (codenamed " Operation Chastise " ), in which three German reservoir dams were selected to be breached in order to damage German infrastructure and manufacturing and power capabilities deriving from
1335-481: A sand dune . By the 6th century BC, the sand already covered the statues of the main temple up to their knees. The temple was forgotten by Europeans until March 1813, when the Swiss researcher Johann Ludwig Burckhardt found the small temple and top frieze of the main temple. When we reached the top of the mountain, I left my guide, with the camels, and descended an almost perpendicular cleft, choaked with sand, to view
1424-469: A significant event. In fact, according to calculations made on the basis of the heliacal rising of the star Sirius (Sothis) and inscriptions found by archaeologists, this date must have been October 22. This image of the king was enhanced and revitalized by the energy of the solar star, and the deified Ramesses the Great could take his place next to Amun-Ra and Ra-Horakhty. Because of the accumulated drift of
1513-431: A temple was dedicated to a queen. The first time, Akhenaten dedicated a temple to his great royal wife, Nefertiti. The rock-cut facade is decorated with two groups of colossi that are separated by the large gateway. The statues, slightly more than 10 m (33 ft) high, are of the king and his queen. On either side of the portal are two statues of the king, wearing the white crown of Upper Egypt (south colossus) and
1602-574: A territorial project that unites all water stakeholders with the goal of preserving and enhancing natural environments. Two main types of reservoirs can be distinguished based on their mode of supply. Circa 3000 BC, the craters of extinct volcanoes in Arabia were used as reservoirs by farmers for their irrigation water. Dry climate and water scarcity in India led to early development of stepwells and other water resource management techniques, including
1691-500: A thicket of papyri. On the west wall, Ramesses II and Nefertari are depicted making offerings to the god Horus and the divinities of the Cataracts— Satis , Anubis and Khnum. The rock-cut sanctuary and the two side chambers are connected to the transverse vestibule and are aligned with the axis of the temple. The bas-reliefs on the side walls of the small sanctuary represent scenes of offerings to various gods made either by
1780-515: Is Piz Terri (3,149 m), on the north-east side of the lake, followed by the Plattenberg (3,041 m), on the east side. The Torrone di Nav (2,832 m) overlooks the lake from the south, while Pizzo Pianca (2,377 m) overlooks the lake from the north. The arch dam Luzzone was completed in 1963. In the years 1997–1998, its height was increased by 17 m. The dam is frequently used by the popular YouTube channel How Ridiculous to perform drop tests, and
1869-449: Is a cryptogram for Ramesses II's throne name , User-Maat-Re . The inner part of the temple has the same triangular layout that most ancient Egyptian temples follow, with rooms decreasing in size from the entrance to the sanctuary. The temple is complex in structure and quite unusual because of its many side chambers. The hypostyle hall (sometimes also called a pronaos) is 18 m (59 ft) long and 16.7 m (55 ft) wide and
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#17330848420741958-471: Is a natural lake whose level was raised by a low dam and into which the River Dee flows or discharges depending upon flow conditions, as part of the River Dee regulation system . This mode of operation is a form of hydraulic capacitance in the river system. Many reservoirs often allow some recreational uses, such as fishing and boating . Special rules may apply for the safety of the public and to protect
2047-480: Is a water reservoir for agricultural use. They are filled using pumped groundwater , pumped river water or water runoff and are typically used during the local dry season. This type of infrastructure has sparked an opposition movement in France, with numerous disputes and, for some projects, protests, especially in the former Poitou-Charentes region where violent demonstrations took place in 2022 and 2023. In Spain, there
2136-437: Is also used technically to refer to certain forms of liquid storage, such the "coolant reservoir" that captures overflow of coolant in an automobile's cooling system. Dammed reservoirs are artificial lakes created and controlled by a dam constructed across a valley and rely on the natural topography to provide most of the basin of the reservoir. These reservoirs can either be on-stream reservoirs , which are located on
2225-399: Is an enlarged lake behind a dam , usually built to store fresh water , often doubling for hydroelectric power generation . Reservoirs are created by controlling a watercourse that drains an existing body of water, interrupting a watercourse to form an embayment within it, excavating, or building any number of retaining walls or levees to enclose any area to store water. The term
2314-501: Is greater acceptance because all beneficiary users are involved in the implementation of the system. The specific debate about substitution reservoirs is part of a broader discussion related to reservoirs used for agricultural irrigation, regardless of their type, and a certain model of intensive agriculture. Opponents view these reservoirs as a monopolization of resources benefiting only a few, representing an outdated model of productive agriculture. They argue that these reservoirs lead to
2403-466: Is needed: it can also be the first part of the water treatment process. The time the water is held before it is released is known as the retention time . This is a design feature that allows particles and silts to settle out, as well as time for natural biological treatment using algae , bacteria and zooplankton that naturally live in the water. However natural limnological processes in temperate climate lakes produce temperature stratification in
2492-528: Is now used by the Aquarius Golf Club. Service reservoirs perform several functions, including ensuring sufficient head of water in the water distribution system and providing water capacity to even-out peak demand from consumers, enabling the treatment plant to run at optimum efficiency. Large service reservoirs can also be managed to reduce the cost of pumping by refilling the reservoir at times of day when energy costs are low. An irrigation reservoir
2581-419: Is stored in the reservoir. Any excess water can be spilled via a specifically designed spillway. Stored water may be piped by gravity for use as drinking water , to generate hydro-electricity or to maintain river flows to support downstream uses. Occasionally reservoirs can be managed to retain water during high rainfall events to prevent or reduce downstream flooding. Some reservoirs support several uses, and
2670-451: Is supported by eight huge Osirid pillars depicting the deified Ramesses linked to the god Osiris , the god of fertility, agriculture, the afterlife, the dead, resurrection, life and vegetation, to indicate the everlasting nature of the pharaoh. The colossal statues along the left-hand wall bear the white crown of Upper Egypt , while those on the opposite side are wearing the double crown of Upper and Lower Egypt (pschent). The bas-reliefs on
2759-466: Is the portion of the reservoir that can be used for flood control, power production, navigation , and downstream releases. In addition, a reservoir's "flood control capacity" is the amount of water it can regulate during flooding. The "surcharge capacity" is the capacity of the reservoir above the spillway crest that cannot be regulated. In the United States, the water below the normal maximum level of
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2848-448: The Ruhr and Eder rivers. The economic and social impact was derived from the enormous volumes of previously stored water that swept down the valleys, wreaking destruction. This raid later became the basis for several films. All reservoirs will have a monetary cost/benefit assessment made before construction to see if the project is worth proceeding with. However, such analysis can often omit
2937-506: The Tropic of Cancer due to Earth 's axial precession over the past 3 millennia, the event's date must have been different when the temple was built. This is compounded by the fact that the temple was relocated from its original setting, so the current alignment may not be as precise as the original one. A graffito inscribed in Greek on the left leg of the colossal seated statue of Ramesses II , on
3026-481: The UNESCO banner; it cost some $ 40 million (equivalent to $ 392.96 million in 2023). Between 1964 and 1968, the entire site was carefully cut into large blocks (up to 30 tons, averaging 20 tons), dismantled, lifted and reassembled in a new location 65 metres higher and 200 metres back from the river, in one of the greatest challenges of archaeological engineering in history. Some structures were even saved from under
3115-450: The double crown (north colossus); these are flanked by statues of the queen. Remarkably, this is one of very few instances in Egyptian art where the statues of the king and his consort have equal size. Traditionally, the statues of the queens stood next to those of the pharaoh, but were never taller than his knees. Ramesses went to Abu Simbel with his wife in the 24th year of his reign. As
3204-401: The double crown of Upper and Lower Egypt . The statue to the immediate left of the entrance was damaged in an earthquake, causing the head and torso to fall away; these fallen pieces were not restored to the statue during the relocation but placed at the statue's feet in the positions originally found. Next to Ramesses's legs are a number of other, smaller statues, none higher than the knees of
3293-400: The goddesses Hathor, Isis , Maat , Mut of Asher, Satis and Taweret ; in one scene Ramesses is presenting flowers or burning incense . The capitals of the pillars bear the face of the goddess Hathor; this type of column is known as Hathoric. The bas-reliefs in the pillared hall illustrate the deification of the king, the destruction of his enemies in the north and south (in these scenes
3382-646: The 1800s, most of which are lined with brick. A good example is the Honor Oak Reservoir in London, constructed between 1901 and 1909. When it was completed it was said to be the largest brick built underground reservoir in the world and it is still one of the largest in Europe. This reservoir now forms part of the southern extension of the Thames Water Ring Main . The top of the reservoir has been grassed over and
3471-675: The Great Temple commemorate Ramesses II's heroic leadership at the Battle of Kadesh . The complex was relocated in its entirety in 1968 to higher ground to avoid it being submerged by Lake Nasser , the Aswan Dam reservoir. As part of International Campaign to Save the Monuments of Nubia , an artificial hill was made from a domed structure to house the Abu Simbel Temples, under the supervision of
3560-429: The Great Temple of the king, there are small statues of princes and princesses next to their parents. In this case they are positioned symmetrically: on the south side (at left as one faces the gateway) are, from left to right, princes Meryatum and Meryre, princesses Meritamen and Henuttawy , and princes Pareherwenemef and Amun-her-khepeshef , while on the north side the same figures are in reverse order. The plan of
3649-520: The Great Temple, dedicated to Ramesses II himself, and the Small Temple, dedicated to his chief wife Queen Nefertari . Construction of the temple complex started in c. 1264 BC and lasted for about 20 years, until 1244 BC. It was known as the Temple of Ramesses, Beloved by Amun . With the passage of time, the temples fell into disuse and the Great Temple eventually became mostly covered by
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3738-710: The Meroitic town of Butana . The Hafirs catch the water during rainy seasons in order to ensure water is available for several months during dry seasons to supply drinking water, irrigate fields and water cattle. The Great Reservoir near the Lion Temple in Musawwarat es-Sufra is a notable hafir in Kush. In Sri Lanka , large reservoirs were created by ancient Sinhalese kings in order to store water for irrigation. The famous Sri Lankan king Parākramabāhu I of Sri Lanka said "Do not let
3827-444: The Small Temple is a simplified version of that of the Great Temple. As in the larger temple dedicated to the king, the hypostyle hall in the smaller temple is supported by six pillars; in this case, however, they are not Osiris pillars depicting the king, but are decorated with scenes with the queen playing the sistrum (an instrument sacred to the goddess Hathor), together with the gods Horus , Khnum , Khonsu , and Thoth , and
3916-485: The US. The capacity, volume, or storage of a reservoir is usually divided into distinguishable areas. Dead or inactive storage refers to water in a reservoir that cannot be drained by gravity through a dam's outlet works , spillway, or power plant intake and can only be pumped out. Dead storage allows sediments to settle, which improves water quality and also creates an area for fish during low levels. Active or live storage
4005-465: The amount of water reaching countries downstream of them, causing water stress between the countries, e.g. the Sudan and Egypt , which damages farming businesses in the downstream countries, and reduces drinking water. Abu Simbel Abu Simbel is a historic site comprising two massive rock-cut temples in the village of Abu Simbel ( Arabic : أبو سمبل ), Aswan Governorate , Upper Egypt , near
4094-523: The area flooded versus power produced, a reservoir built for hydro- electricity generation can either reduce or increase the net production of greenhouse gases when compared to other sources of power. A study for the National Institute for Research in the Amazon found that hydroelectric reservoirs release a large pulse of carbon dioxide from decay of trees left standing in the reservoirs, especially during
4183-428: The base of the dam or some distance away. In a flat river valley a reservoir needs to be deep enough to create a head of water at the turbines; and if there are periods of drought the reservoir needs to hold enough water to average out the river's flow throughout the year(s). Run-of-the-river hydro in a steep valley with constant flow needs no reservoir. Some reservoirs generating hydroelectricity use pumped recharge:
4272-495: The body covered with sand to above the shoulders; of the other two, the bonnets only appear. It is difficult to determine, whether these statues are in a sitting or standing posture; their backs adhere to a portion of rock, which projects from the main body, and which may represent a part of a chair, or may be merely a column for support. Burckhardt talked about his discovery with the Italian explorer Giovanni Belzoni , who travelled to
4361-565: The border with Sudan . It is located on the western bank of Lake Nasser , about 230 km (140 mi) southwest of Aswan (about 300 km (190 mi) by road). The twin temples were originally carved out of the mountainside in the 13th century BC, during the 19th Dynasty reign of the Pharaoh Ramesses II . Their huge external rock relief figures of Ramesses II have become iconic. His wife, Nefertari , and children can be seen in smaller figures by his feet. Sculptures inside
4450-547: The building of a reservoir at Girnar in 3000 BC. Artificial lakes dating to the 5th century BC have been found in ancient Greece. The artificial Bhojsagar lake in present-day Madhya Pradesh state of India, constructed in the 11th century, covered 650 square kilometres (250 sq mi). The Kingdom of Kush invented the Hafir , a type of reservoir, during the Meroitic period . 800 ancient and modern hafirs have been registered in
4539-442: The context of system-wide demands and supplies. In many countries large reservoirs are closely regulated to try to prevent or minimize failures of containment. While much of the effort is directed at the dam and its associated structures as the weakest part of the overall structure, the aim of such controls is to prevent an uncontrolled release of water from the reservoir. Reservoir failures can generate huge increases in flow down
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#17330848420744628-497: The dam located at the narrowest practical point to provide strength and the lowest cost of construction. In many reservoir construction projects, people have to be moved and re-housed, historical artifacts moved or rare environments relocated. Examples include the temples of Abu Simbel (which were moved before the construction of the Aswan Dam to create Lake Nasser from the Nile in Egypt ),
4717-401: The deified king Ramesses, and the gods Amun Ra and Ptah . Ra-Horakhty , Amun Ra and Ptah were the main divinities in that period and their cult centers were at Heliopolis , Thebes and Memphis respectively. It is believed that the axis of the temple was positioned by the ancient Egyptian architects in such a way that on October 22 and February 22, the rays of the sun would penetrate
4806-460: The developed world Naturally occurring lakes receive organic sediments which decay in an anaerobic environment releasing methane and carbon dioxide . The methane released is approximately 8 times more potent as a greenhouse gas than carbon dioxide. As a human-made reservoir fills, existing plants are submerged and during the years it takes for this matter to decay, will give off considerably more greenhouse gases than lakes do. A reservoir in
4895-507: The downstream river to maintain river quality, support fisheries, to maintain downstream industrial and recreational uses or for a range of other purposes. Such releases are known as compensation water . The units used for measuring reservoir areas and volumes vary from country to country. In most of the world, reservoir areas are expressed in square kilometers; in the United States, acres are commonly used. For volume, either cubic meters or cubic kilometers are widely used, with acre-feet used in
4984-440: The environmental impacts of dams and the reservoirs that they contain. Some impacts, such as the greenhouse gas production associated with concrete manufacture, are relatively easy to estimate. Other impacts on the natural environment and social and cultural effects can be more difficult to assess and to weigh in the balance but identification and quantification of these issues is now commonly required in major construction projects in
5073-491: The first decade after flooding. This elevates the global warming impact of the dams to levels much higher than would occur by generating the same power from fossil fuels . According to the World Commission on Dams report (Dams And Development), when the reservoir is relatively large and no prior clearing of forest in the flooded area was undertaken, greenhouse gas emissions from the reservoir could be higher than those of
5162-413: The flow in highly managed systems, taking in water during high flows and releasing it again during low flows. In order for this to work without pumping requires careful control of water levels using spillways . When a major storm approaches, the dam operators calculate the volume of water that the storm will add to the reservoir. If forecast storm water will overfill the reservoir, water is slowly let out of
5251-580: The hydroelectric reservoirs there do emit greenhouse gases, it is on a much smaller scale than thermal power plants of similar capacity. Hydropower typically emits 35 to 70 times less greenhouse gases per TWh of electricity than thermal power plants. A decrease in air pollution occurs when a dam is used in place of thermal power generation, since electricity produced from hydroelectric generation does not give rise to any flue gas emissions from fossil fuel combustion (including sulfur dioxide , nitric oxide and carbon monoxide from coal ). Dams can produce
5340-424: The hypostyle hall, one enters the second pillared hall, which has four pillars decorated with beautiful scenes of offerings to the gods. There are depictions of Ramesses and Nefertari with the sacred boats of Amun and Ra-Horakhty. This hall gives access to a transverse vestibule, in the middle of which is the entrance to the sanctuary. Here, on a black wall, are rock cut sculptures of four seated figures: Ra-Horakhty ,
5429-517: The idea was made into a proposal by architects Jane Drew and Maxwell Fry and civil engineer Ove Arup . They considered that raising the temples ignored the effect of erosion of the sandstone by desert winds. However, the proposal, though acknowledged to be extremely elegant, was rejected. The salvage of the Abu Simbel temples began in 1964 by a multinational team of archeologists, engineers and skilled heavy equipment operators working together under
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#17330848420745518-404: The king is accompanied by his wife), and the queen making offerings to the goddesses Hathor and Mut. The hypostyle hall is followed by a vestibule, access to which is given by three large doors. On the south and the north walls of this chamber there are two graceful and poetic bas-reliefs of the king and his consort presenting papyrus plants to Hathor, who is depicted as a cow on a boat sailing in
5607-432: The landscape is relatively flat. Other service reservoirs can be storage pools, water tanks or sometimes entirely underground cisterns , especially in more hilly or mountainous country. Modern reserviors will often use geomembrane liners on their base to limit seepage and/or as floating covers to limit evaporation, particularly in arid climates. In the United Kingdom, Thames Water has many underground reservoirs built in
5696-438: The lowest holds were placed several meters above the ground to deter casual visitors from climbing on them. This Ticino location article is a stub . You can help Misplaced Pages by expanding it . This article about a dam or floodgate is a stub . You can help Misplaced Pages by expanding it . Reservoir A reservoir ( / ˈ r ɛ z ər v w ɑːr / ; from French réservoir [ʁezɛʁvwaʁ] )
5785-470: The modern use of rolled clay. The water stored in such reservoirs may stay there for several months, during which time normal biological processes may substantially reduce many contaminants and reduce turbidity . The use of bank-side reservoirs also allows water abstraction to be stopped for some time, for instance when the river is unacceptably polluted or when flow conditions are very low due to drought . The London water supply system exhibits one example of
5874-593: The new top water level exceeds the watershed height on one or more of the feeder streams such as at Llyn Clywedog in Mid Wales . In such cases additional side dams are required to contain the reservoir. Where the topography is poorly suited to forming a single large reservoir, a number of smaller reservoirs may be constructed in a chain, as in the River Taff valley where the Llwyn-on , Cantref and Beacons Reservoirs form
5963-415: The operating rules may be complex. Most modern reservoirs have a specially designed draw-off tower that can discharge water from the reservoir at different levels, both to access water as the water level falls, and to allow water of a specific quality to be discharged into the downstream river as "compensation water": the operators of many upland or in-river reservoirs have obligations to release water into
6052-428: The original streambed of the downstream river and are filled by creeks , rivers or rainwater that runs off the surrounding forested catchments, or off-stream reservoirs , which receive diverted water from a nearby stream or aqueduct or pipeline water from other on-stream reservoirs. Dams are typically located at a narrow part of a downstream of a natural basin. The valley sides act as natural walls, with
6141-418: The pharaoh, depicting: his chief wife, Nefertari Meritmut ; his queen mother Mut-Tuy ; his first two sons, Amun-her-khepeshef and Ramesses B ; and his first six daughters: Bintanath , Baketmut, Nefertari , Meritamen , Nebettawy and Isetnofret . The façade behind the colossi is 33 m (108 ft) high and 38 m (125 ft) wide. It carries a frieze depicting twenty-two baboons worshipping
6230-477: The pre-flooded landscape, noting that forest lands, wetlands, and preexisting water features all released differing amounts of carbon dioxide and methane both pre- and post-flooding. The Tucuruí Dam in Brazil (completed in 1984) had only 0.4 times the impact on global warming than would generating the same power from fossil fuels. A two-year study of carbon dioxide and methane releases in Canada concluded that while
6319-437: The quality of the water and the ecology of the surrounding area. Many reservoirs now support and encourage less formal and less structured recreation such as natural history , bird watching , landscape painting , walking and hiking , and often provide information boards and interpretation material to encourage responsible use. Water falling as rain upstream of the reservoir, together with any groundwater emerging as springs,
6408-464: The relocation of the village of Capel Celyn during the construction of Llyn Celyn , and the relocation of Borgo San Pietro of Petrella Salto during the construction of Lake Salto . Construction of a dammed reservoir will usually require the river to be diverted during part of the build, often through a temporary tunnel or by-pass channel. In hilly regions, reservoirs are often constructed by enlarging existing lakes. Sometimes in such reservoirs,
6497-627: The reservoir prior to, and during, the storm. If done with sufficient lead time, the major storm will not fill the reservoir and areas downstream will not experience damaging flows. Accurate weather forecasts are essential so that dam operators can correctly plan drawdowns prior to a high rainfall event. Dam operators blamed a faulty weather forecast on the 2010–2011 Queensland floods . Examples of highly managed reservoirs are Burrendong Dam in Australia and Bala Lake ( Llyn Tegid ) in North Wales . Bala Lake
6586-522: The rising sun with upraised arms and a stele recording the marriage of Ramesses to a daughter of king Ḫattušili III , which sealed the peace between Egypt and the Hittites . The entrance doorway itself is surmounted by bas-relief images of the king worshipping the falcon-headed Ra Horakhty , whose statue stands in a large niche. Ra holds the hieroglyph user and a feather in his right hand, with Maat (the goddess of truth and justice) in his left; this
6675-410: The river; they are all of the same size, stand with one foot before the other, and are accompanied by smaller figures... Having, as I supposed, seen all the antiquities of Ebsambal, I was about to ascend the sandy side of the mountain by the same way I had descended; when having luckily turned more to the southward, I fell in with what is yet visible of four immense colossal statues cut out of the rock, at
6764-434: The sanctuary and illuminate the sculptures on the back wall, except for the statue of Ptah , a god connected with the realm of the dead , who always remained in the dark. People gather at Abu Simbel on these days to witness this. These dates are allegedly the king's birthday and coronation day, respectively. There is no direct evidence to support this. It is logical to assume, however, that these dates had some relation to
6853-460: The site, but was unable to dig out an entry to the temple. Belzoni returned in 1817, this time succeeding in his attempt to enter the complex. A detailed early description of the temples, together with contemporaneous line drawings, can be found in Edward William Lane 's Description of Egypt (1825–1828). In 1959, an international donations campaign to save the monuments of Nubia began:
6942-471: The south side of the entrance to the temple records that: When King Psammetichus (i.e., Psamtik II ) came to Elephantine, this was written by those who sailed with Psammetichus the son of Theocles, and they came beyond Kerkis as far as the river permits. Those who spoke foreign tongues (Greek and Carians who also scratched their names on the monument) were led by Potasimto , the Egyptians by Amasis. Kerkis
7031-523: The southernmost relics of this ancient civilization were under threat from the rising waters of the Nile that were about to result from the construction of the Aswan High Dam . One scheme to save the temples was based on an idea by William MacQuitty to build a clear freshwater dam around the temples, with the water inside kept at the same height as the Nile. There were to be underwater viewing chambers. In 1962
7120-439: The temple of Ebsambal, of which I had heard many magnificent descriptions. There is no road at present to this temple... It stands about twenty feet above the surface of the water, entirely cut out of the almost perpendicular rocky side of the mountain, and in complete preservation. In front of the entrance are six erect colossal figures, representing juvenile persons, three on each side, placed in narrow recesses, and looking towards
7209-416: The time, and features four large statues of Ramesses II in the facade. The smaller temple is dedicated to the goddess Hathor , personified by Nefertari , Ramesses's most beloved of his many wives. The temple is now open to the public. The Great Temple at Abu Simbel, which took about twenty years to build, was completed around year 24 of the reign of Ramesses the Great (which corresponds to 1265 BC). It
7298-493: The use of bank-side storage: here water is taken from the River Thames and River Lee into several large Thames-side reservoirs, such as Queen Mary Reservoir that can be seen along the approach to London Heathrow Airport . Service reservoirs store fully treated potable water close to the point of distribution. Many service reservoirs are constructed as water towers , often as elevated structures on concrete pillars where
7387-598: The walls of the pronaos depict battle scenes in the military campaigns that Ramesses waged. Much of the sculpture is given to the Battle of Kadesh , on the Orontes river in present-day Syria , in which the Egyptian king fought against the Hittites . The most famous relief shows the king on his chariot shooting arrows against his fleeing enemies, who are being taken prisoner. Other scenes show Egyptian victories in Libya and Nubia. From
7476-412: The water, which tends to partition some elements such as manganese and phosphorus into deep, cold anoxic water during the summer months. In the autumn and winter the lake becomes fully mixed again. During drought conditions, it is sometimes necessary to draw down the cold bottom water, and the elevated levels of manganese in particular can cause problems in water treatment plants. In 2005, about 25% of
7565-439: The waters of Lake Nasser. Today, a few hundred tourists visit the temples daily. Most visitors arrive by road from Aswan , the nearest city. Others arrive by plane at Abu Simbel Airport , an airfield specially constructed for the temple complex whose sole destination is Aswan International Airport . The complex consists of two temples. The larger one is dedicated to Ra -Horakhty, Ptah and Amun , Egypt's three state deities of
7654-476: The world's 33,105 large dams (over 15 metres in height) were used for hydroelectricity. The U.S. produces 3% of its electricity from 80,000 dams of all sizes. An initiative is underway to retrofit more dams as a good use of existing infrastructure to provide many smaller communities with a reliable source of energy. A reservoir generating hydroelectricity includes turbines connected to the retained water body by large-diameter pipes. These generating sets may be at
7743-457: Was dedicated to the gods Amun , Ra-Horakhty , and Ptah , as well as to the deified Ramesses himself. It is generally considered the grandest and most beautiful of the temples commissioned during the reign of Ramesses II, and one of the most beautiful in Egypt. The single entrance is flanked by four colossal, 20 m (66 ft) statues, each representing Ramesses II seated on a throne and wearing
7832-528: Was located near the Fifth Cataract of the Nile "which stood well within the Cushite Kingdom." The temple of Hathor and Nefertari , also known as the Small Temple, was built about 100 m (330 ft) northeast of the temple of Ramesses II and was dedicated to the goddess Hathor and Ramesses II's chief consort, Nefertari. This was in fact the second time in ancient Egyptian history that
7921-556: Was very important to the Egyptians because it was a source of gold and many other precious trade goods. He, therefore, built several grand temples there in order to impress upon the Nubians Egypt's might and Egyptianize the people of Nubia. The most prominent temples are the rock-cut temples near the modern village of Abu Simbel , at the Second Nile Cataract, the border between Lower Nubia and Upper Nubia. There are two temples,
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