The Thames Barrier is a movable barrier system, designed to prevent the floodplain of most of Greater London from being flooded by exceptionally high tides and storm surges moving up from the North Sea. It has been operational since 1982; when needed, it is closed during high tide. Built 3 km due east of the Isle of Dogs, its northern bank is in Silvertown in the London Borough of Newham and its southern bank is in the New Charlton area of the Royal Borough of Greenwich; the report of Sir Hermann Bondi on the North Sea flood of 1953 affecting parts of the Thames Estuary and parts of London was a big factor in the planning of the barrier. The concept of the rotating gates was devised by Charles Draper. In 1969, from his parents' house in Pellatt Grove, Wood Green, London, he constructed a working model; the novel rotating cylinders were based on the design of the taps on his gas cooker. The barrier was designed by Rendel and Tritton for the Greater London Council and tested at the Hydraulics Research Station, Wallingford.

The site at New Charlton was chosen because of the relative straightness of the banks, because the underlying river chalk was strong enough to support the barrier. Work began at the barrier site in 1974 and construction, undertaken by a Costain/Hollandsche Beton Maatschappij/Tarmac Construction consortium, was complete by 1982; the gates of the barrier were made by Cleveland Bridge UK Ltd at Dent's Wharf on the River Tees. In addition to the barrier, the flood defences for 18 kilometres down river were raised and strengthened; the barrier was opened on 8 May 1984 by Queen Elizabeth II. The barrier cost £461 million. Total construction cost was around £534 million with an additional £100 million for river defences. Built across a 520-metre wide stretch of the river, the barrier divides the river into four 61-metre and two 30-metre navigable spans. There are four smaller non-navigable channels between nine concrete piers and two abutments; the flood gates across the openings are circular segments in cross section, they operate by rotating, raised to allow "underspill" to allow operators to control upstream levels and a complete 180 degree rotation for maintenance.

All the gates are hollow and made of steel up to 40 millimetres thick. The gates are filled with water when empty as they emerge from the river; the four large central gates weigh 3,700 tonnes each. Four radial gates by the river banks about 30 metres wide, can be lowered; these gate openings, unlike the main six, are non-navigable. A Thames Barrier flood defence closure is triggered when a combination of high tides forecast in the North Sea and high river flows at the tidal limit at Teddington weir indicate that water levels would exceed 4.87 metres in central London. Though Teddington marks the Normal Tidal Limit, in periods of high fluvial flow the tidal influence can be seen as far upstream as East Molesey on the Thames. During the barrier's entire history up to October 2019, there have been 186 flood defence closures; the barrier was closed twice on 9 November 2007 after a storm surge in the North Sea, compared to the one in 1953. The main danger of flooding from the surge was on the coast above the Thames Barrier, where evacuations took place, but the winds abated a little and, at the Thames Barrier, the 9 November 2007 storm surge did not coincide with high tide.

On 20 August 1989, hours after the Marchioness disaster, the barrier was closed against a spring tide for 16 hours "to assist the diving and salvage operations". The barrier has survived 15 boat collisions without serious damage. On 27 October 1997, the barrier was damaged when the dredger MV Sand Kite, operating in thick fog, hit one of the Thames Barrier's piers; as the ship started to sink she dumped her 3,300-tonne load of aggregate sinking by the bow on top of one of the barrier's gates where she lay for several days. The gate could not be closed as it was covered in a thick layer of gravel. A longer-term problem was the premature loss of paint on the flat side of the gate caused by abrasion; the vessel was refloated in mid-November 1997. The annual full test closure in 2012 was scheduled for 3 June to coincide with the Thames pageant celebrating Queen Elizabeth II's Diamond Jubilee. Flood risk manager Andy Batchelor said the pageant gave the Environment Agency "a unique opportunity to test its design for a longer period than we would be able to", that the more stable tidal conditions in central London that resulted would help the vessels taking part.

The barrier was commissioned by the Greater London Council under the guidance of Ray Horner. After the 1986 abolition of the GLC it was operated successively by Thames Water Authority and the National Rivers Authority until April 1996 when it passed to the Environment Agency; the barrier was designed to protect London against a high flood level up to the year 2030, after which the protection would decrease, while remaining within acceptable limits. At the time of its construction, the barrier was expected to be used 2–3 times per year. By the mid-2000s it was being operated 6–7 times a year. In the 2010s, the barrier was closed twice a year but the average is still 6-7 due to the barrier being raised 50 times in 2013-14; this defence level included long-term changes in land levels as understood at that time. Despite global warming and a greater predicted rate of sea

The valleys of Bhutan are carved into the Himalaya by Bhutan's rivers, fed by glacial melt and monsoon rains. As Bhutan is landlocked in the mountainous eastern Himalaya, much of its population is concentrated in valleys and lowlands, separated by rugged southward spurs of the Inner Himalaya. Despite modernization and development of transport in Bhutan, including a national highway system, travel from one valley to the next remains difficult. Western valleys are bound to the east by the Black Mountains in central Bhutan, which form a watershed between two major river systems, the Mo Chhu and the Drangme Chhu. Central valleys are separated from the east by the Donga Range; the more isolated mountain valleys protect several tiny, distinct linguistic groups. Reflecting this isolation, most valleys have their own local protector deities. Throughout the history of Bhutan, its valleys and lowlands were the object of political control. During the emergence of Bhutan as an independent state in the 17th century, Shabdrung Ngawang Namgyal conquered the western valleys and constructed dzong fortresses to repel invasions from Tibet.

His lieutenant, Penlop of Trongsa Mingyur Tenpa, went on to conquer the valleys in central and eastern Bhutan for the new theocratic government. As a result, each major valley contains a dzong fortress; the dry, plain-like valleys of western and central Bhutan tend to be densely populated and intensely cultivated. The wetter eastern valleys, tend to be steeper, narrower ravines, with isolated settlements dug directly into mountainsides. In the western regions, valleys produce barley and dairy in the north, while southern reaches produce bananas and rice. Below is a list of the valleys of Bhutan: Mountains of Bhutan

Tiffany Mynx is an American pornographic actress and film director. She is a member of the AVN, XRCO Halls of Fame. In 1992 she moved to Los Angeles, where she lived with her grandmother, started to work as an exotic dancer as well as appearing in photo spreads for magazines such as High Society and Penthouse, her first on-camera work was for a Penthouse video, while her first porn role was in the VCA movie The DJ. In 1998 she wrote, produced and starred in Asswoman in Wonderland. Mynx has directed The Toe Story, she was inducted into the AVN Hall of Fame in 2001, the XRCO Hall of Fame in 2003. 1994 AVN Award – Best Anal Sex Scene - Video – Sodomania 5: Euro/American Style 1994 F. O. X. E. Award – Female Fan Favorite 1998 F. O. X. E. Award – Female Fan Favorite 1998 XRCO Award – Best Girl-Girl Scene – Miscreants 1999 XRCO Award – Best Group Scene – Asswoman in Wonderland 2001 AVN Hall of Fame inductee 2003 XRCO Hall of Fame inductee 2007 AVN Award – Best Sex Scene Coupling - Video – Slave Dolls 2 Tiffany Mynx on IMDb Tiffany Mynx at the Internet Adult Film Database Tiffany Mynx at the Adult Film Database