A tunnel is an underground or undersea passageway. It is dug through surrounding soil, earth or rock, or laid under water, and is usually completely enclosed except for the two portals common at each end, though there may be access and ventilation openings at various points along the length. A pipeline differs significantly from a tunnel, though some recent tunnels have used immersed tube construction techniques rather than traditional tunnel boring methods.
The Aswan Dam, or Aswan High Dam, is one of the world's largest embankment dams, which was built across the Nile in Aswan, Egypt, between 1960 and 1970. When it was completed, it was the tallest earthen dam in the world, surpassing the Chatuge Dam in the United States. The dam, which created the Lake Nasser reservoir, was built 7 km (4.3 mi) upstream of the Aswan Low Dam, which had been completed in 1902 and was already at its maximum utilization. Construction of the High Dam became a key objective of the military regime that took power following the 1952 Egyptian Revolution. With its ability to better control flooding, provide increased water storage for irrigation and generate hydroelectricity, the dam was seen as pivotal to Egypt's planned industrialization. Like the earlier implementation, the High Dam has had a significant effect on the economy and culture of Egypt.
An adit or stulm is a horizontal or nearly horizontal passage to an underground mine. Miners can use adits for access, drainage, ventilation, and extracting minerals at the lowest convenient level. Adits are also used to explore for mineral veins. Although most strongly associated with mining, the term adit is sometimes also used in the context of underground excavation for non-mining purposes; for example, to refer to smaller underground passageways excavated for underground metro systems, to provide pedestrian access to stations, and for access required during construction.
The Li River or Li Jiang is the name for the upper reaches of the Gui River in northeastern Guangxi, China. It is part of the Xijiang River system in the Pearl River basin, flowing 164 kilometres (102 mi) from Xing'an County to Pingle County.
The Rhine–Main–Danube Canal, is a canal in Bavaria, Germany. Connecting the Main and the Danube rivers across the European Watershed, it runs from Bamberg via Nuremberg to Kelheim. The canal connects the North Sea and Atlantic Ocean to the Black Sea, providing a navigable artery between the Rhine delta, and the Danube Delta in south-eastern Romania and south-western Ukraine. The present canal was completed in 1992 and is 171 kilometres (106 mi) long.
The Clyde River is an open intermediate tide-dominated drowned valley estuary or perennial river that flows into the Tasman Sea at Batemans Bay, located in the South Coast region of New South Wales, Australia.
The Durance is a major river in Southeastern France. A left tributary of the Rhône, it is 323.2 km (200.8 mi) long. Its drainage basin is 14,472 km2 (5,588 sq mi).
The Cooum River, or simply Koovam, is one of the shortest classified rivers draining into the Bay of Bengal. This river is about 72 km (45 mi) in length, flowing 32 km (20 mi) in the city of Chennai and the rest in rural part. The river is highly polluted in the urban area (Chennai). Along with the Adyar River running parallel to the south and the Kosasthalaiyar River, the river trifurcates the city of Chennai and separates Northern Chennai from Central Chennai. It is also sometimes known as Thiruvallikenni river
Periyar, is the longest river and the river with the largest discharge potential in the Indian state of Kerala. It is one of the few perennial rivers in the region and provides drinking water for several major towns. The Periyar is of utmost significance to the economy of Kerala. It generates a significant proportion of Kerala's electrical power via the Idukki Dam and flows along a region of industrial and commercial activity. The river also provides water for irrigation and domestic use throughout its course besides supporting a rich fishery. Due to these reasons, the river has been named the "Lifeline of Kerala". Kochi city, in the vicinity of the river mouth, draws its water supply from Aluva, an upstream site sufficiently free of seawater intrusion. Twenty five percent of Kerala's industries are along the banks of the Periyar. These are mostly crowded within a stretch of 5 kilometres (3 mi) in the Eloor-Edayar region (Udhyogamandal), about 10 kilometres (6 mi) north of Kochi harbor.
The Robert-Bourassa generating station, formerly known as La Grande-2 (LG-2), is a hydroelectric power station on the La Grande River that is part of Hydro-Québec's James Bay Project in Canada. The station can generate 5,616 MW and its 16 units were gradually commissioned between 1979 and 1981. Annual generation is in the vicinity of 26500 GWh.
The Fisher Power Station is a conventional hydroelectric power station located in north-western Tasmania, Australia.
Iron Cove Creek, a southern tributary of the Parramatta River, is an urban stream west of Sydney Harbour, located in the inner-western Sydney suburbs of Croydon, Ashfield, Haberfield and Five Dock in New South Wales, Australia.
The Orange–Fish Tunnel, constructed between 1966 and 1975, is an 82.8-kilometre (51.4-mile) long irrigation tunnel in central South Africa, built to divert water from the Orange River to the Fish River valley. It is the longest continuous enclosed aqueduct in the southern hemisphere.
The Tongariro Power Scheme is a 360 MW hydroelectricity scheme in the central North Island of New Zealand. The scheme diverts water from tributaries of the Rangitikei, Whangaehu, Whanganui, and Tongariro rivers. These rivers drain a 2,600-square-kilometre (1,000 sq mi) area including Ruapehu, Ngauruhoe, Tongariro and the western Kaimanawa Ranges. The water diverted from these rivers is sent through canals and tunnels to generate electricity at three hydro power stations, Rangipo (120 MW), Tokaanu (240 MW) and Mangaio (2 MW). The water is then discharged into Lake Taupō where it adds to the water storage in the lake and enables additional electricity generation in the succession of power stations down the Waikato River.
The Adyar River, which originates near the Chembarambakkam Lake in the Kanchipuram district, is one of the three rivers that winds through Chennai, Tamil Nadu, India, and joins the Bay of Bengal at the Adyar estuary. The 42.5-kilometre (26.4 mi) long river contributes to the estuarine ecosystem of Chennai. Despite the high pollution levels, boating and fishing take place in this river. The river collects surplus water from about 200 tanks and lakes, small streams and the rainwater drains in the city, with a combined catchment area of 860 square kilometres (331 sq mi). Most of the waste from the city is drained into this river and the Cooum.
Idamalayar Dam is a multipurpose concrete gravity dam located at Ennakkal between Ayyampuzha and Bhoothathankettu in Ernakulam district of Kerala on the Idamalayar, a tributary of the Periyar River in Kerala, South India. The dam however extends east as far as Malakkappara. Completed in 1985, with a length of 373 metres (1,224 ft) and a height of 102.8 metres (337 ft), the dam created a multipurpose reservoir covering 28.3 km2 (10.9 sq mi) in the scenic hills of the Anamalais.
Overdeepening is a characteristic of basins and valleys eroded by glaciers. An overdeepened valley profile is often eroded to depths which are hundreds of metres below the lowest continuous surface line along a valley or watercourse. This phenomenon is observed under modern day glaciers, in salt-water fjords and fresh-water lakes remaining after glaciers melt, as well as in tunnel valleys which are partially or totally filled with sediment. When the channel produced by a glacier is filled with debris, the subsurface geomorphic structure is found to be erosionally cut into bedrock and subsequently filled by sediments. These overdeepened cuts into bedrock structures can reach a depth of several hundred metres below the valley floor.
The Pandoh Dam is an embankment dam on the Beas River in Mandi district of Himachal Pradesh, India. Under the Beas Project, the dam was completed in 1977 and its primary purpose is hydroelectric power generation. Part of a run-of-the-river power scheme, it diverts the waters of the Beas to the southwest through a 38 km (24 mi) long system of tunnels and channels. The water is used for power generation at the Dehar Power House before being discharged into the Sutlej River, connecting both rivers. The power house has an installed capacity of 990 MW. The system diverts 256 cumecs of Beas waters to the Satluj River. The project was completed in 1977.
The Baiyang River, also known under a Mongolian name transcribed in Chinese as Namuguolei, is a river in Xinjiang Uighur Autonomous Region of China. It flows through the region's Tacheng Prefecture and the Urho District of Karamay City. The river's total length is estimated at 170 kilometres (110 mi), and the average annual flow at 109 million cubic metres (88,000 acre⋅ft). The river's basin occupies 16,400 square kilometres (6,300 sq mi),
The Vorotan Cascade, or the ContourGlobal Hydro Cascade, is a cascade on the Vorotan River in Syunik Province, Armenia. It was built to produce hydroelectric power and provide irrigation water. The Vorotan Cascade consists of three hydroelectric power plants and five reservoirs with a combined installed capacity of 404.2 MW. It is one of the main power generation complexes in Armenia.
