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Head (hydrology)
In hydrology, the head is the point on a watercourse up to which it has been artificially broadened and/or raised by an Dam, impoundment. Above the head of the reservoir natural conditions prevail; below it the water level above the Stream bed, riverbed has been raised by the impoundment and its Discharge (hydrology), flow rate reduced, unless and until banks, barrages, weir sluices or dams are overcome (overtopped), whereby a less frictional than natural course will exist (mid-level and surface rather than bed and bank currents) resulting in flash flooding below. In principle, a distinction must be drawn between the head of a reservoir impounded by a dam, and the head of a works resulting from a barrage (dam), barrage or canal locks. Head of a reservoir A head's location varies with the height of the water level against the dam. Since there is only an extremely low flow within the reservoir so no water level gradient, the head can be clearly seen: where the farthest watercou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fürstenteich 042
The Fürstenteich is a reservoir near Silberhütte (Harzgerode), Silberhütte in the German state of Saxony-Anhalt. It has an earth-filled dam with an impervious core. It impounds the Teufelsgrundbach (Selke), Teufelsgrundbach stream. Construction The dam was based on sedimented shale and has an internal impervious core of organic clays (grass sods). During renovation work about 70 cm of the surface layer on the old downstream face was removed and replaced by layers of shale material. That was covered with a 10 cm thick layer of topsoil sown with grass seed. On the upstream side, 60 cm was removed and on a 30 cm thick layer of stone chippings a similarly thick protective layer of ballast. The dam was also raised in height by about 1 metre. After removing 90 cm of the old dam crest, a metre-wide toe wall was integrated from the subgrade (''Planum''). This extends as far as the cohesive earth material of the old dam core. The old wooden outlet channel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moselle
The Moselle ( , ; ; ) is a river that rises in the Vosges mountains and flows through north-eastern France and Luxembourg to western Germany. It is a bank (geography), left bank tributary of the Rhine, which it joins at Koblenz. A small part of Belgium is in its drainage basin, basin as it includes the Sauer and the Our River, Our. Its lower course "twists and turns its way between Trier and Koblenz along one of Germany's most beautiful river valleys."''Moselle: Holidays in one of Germany's most beautiful river valleys'' at www.romantic-germany.info. Retrieved 23 Jan 2016. In this section the land to the north is the Eifel which stretches into Belgium; to the south lies the Hunsrück. The river flows through a region that was cultivated by the Romans. Today, its hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Staff (head) Gauge
A staff gauge or head gauge is calibrated scale which is used to provide a visual indication of liquid level. When installed perpendicular to an inclined or sloped surface, a staff gauge is usually calibrated so that the indicated level is the true vertical level. Staff gauges are commonly installed at stream gauging stations to indicate the water stage or water level. They are also used to indicate the level (and hence flow rate) in open channel primary devices (flumes or weirs); see discharge (hydrology). See also * Head (hydrology) In hydrology, the head is the point on a watercourse up to which it has been artificially broadened and/or raised by an Dam, impoundment. Above the head of the reservoir natural conditions prevail; below it the water level above the Stream bed, ... * Level staff {{water-stub Water supply Hydrology instrumentation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydraulic Head
Hydraulic head or piezometric head is a measurement related to liquid pressure (normalized by specific weight) and the liquid elevation above a vertical datum., 410 pages. See pp. 43–44., 650 pages. See p. 22, eq.3.2a. It is usually measured as an equivalent liquid surface elevation, expressed in units of length, at the entrance (or bottom) of a piezometer. In an aquifer, it can be calculated from the depth to water in a piezometric well (a specialized water well), and given information of the piezometer's elevation and screen depth. Hydraulic head can similarly be measured in a column of water using a standpipe piezometer by measuring the height of the water surface in the tube relative to a common datum. The hydraulic head can be used to determine a ''hydraulic gradient'' between two or more points. Definition In fluid dynamics, the ''head'' at some point in an incompressible (constant density) flow is equal to the height of a static column of fluid whose pressure at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flood Tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables can be used for any given locale to find the predicted times and amplitude (or "tidal range"). The predictions are influenced by many factors including the alignment of the Sun and Moon, the phase and amplitude of the tide (pattern of tides in the deep ocean), the amphidromic systems of the oceans, and the shape of the coastline and near-shore bathymetry (see '' Timing''). They are however only predictions, the actual time and height of the tide is affected by wind and atmospheric pressure. Many shorelines experience semi-diurnal tides—two nearly equal high and low tides each day. Other locations have a diurnal tide—one high and low tide each day. A "mixed tide"—two uneven magnitude tides a day—is a third regular category. Tid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ebb Tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravity, gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables can be used for any given locale to find the predicted times and amplitude (or "tidal range"). The predictions are influenced by many factors including the alignment of the Sun and Moon, the #Phase and amplitude, phase and amplitude of the tide (pattern of tides in the deep ocean), the amphidromic systems of the oceans, and the shape of the coastline and near-shore bathymetry (see ''#Timing, Timing''). They are however only predictions, the actual time and height of the tide is affected by wind and atmospheric pressure. Many shorelines experience semi-diurnal tides—two nearly equal high and low tides each day. Other locations have a diurnal cycle, diurnal tide—one high and low tide each day. A "mixed tide"—two uneven magnitude ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jubilee River
The Jubilee River is an artificial flood-relief channel in southern England. It is long and is on average wide. It was constructed in the late 1990s and early 2000s to take overflow from the River Thames and so alleviate flooding to areas in and around the towns of Maidenhead, Windsor, and Eton in the counties of Berkshire and Buckinghamshire. It achieves this by taking water from the left (at this point eastern) bank of the Thames upstream of Boulter's Lock near Maidenhead and returning it via the north bank downstream of Eton. Although successful in its stated aims, residents of villages downstream, such as Wraysbury, claim it has increased flooding in those locations. Construction Parts of the towns of Windsor, Eton and Maidenhead are prone to flooding, because they are built on the flood plain of the River Thames. The concept of a parallel channel which could take water from the Thames above Maidenhead and return it below Windsor was conceived in the 1980s, and became ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flood Meadow
A flood-meadow (or floodmeadow) is an area of grassland or pasture beside a river, subject to seasonal flooding.Huhta, Ari‐Pekka, Rautio, Pasi (2014). Flood meadows in Finland - their development during the past century. '' Nordic Journal of Botany'' 32 (6): 858–70 Flood-meadows are distinct from water-meadows in that the latter are artificially created and maintained, with flooding controlledEmma Rothero, Sophie Lake, David Gowing, eds. Floodplain Meadows – Beauty and Utility: A Technical Handbook'' (Floodplain Meadows Partnership; 2016) on a seasonal and even daily basis. Examples Austria: * Hohenau an der March Bosnia and Herzegovina: * List of karst polje in Bosnia and Herzegovina Estonia: * Emajõe flood-meadow * Kasari, Matsalu National Park Finland: * Mattholmsfladan, Pargas * Levänluhta, Isokyrö Ireland: * Shannon Callows United Kingdom: * Angel & Greyhound Meadow, Oxford * Christchurch Meadows, Reading * Christ Church Meadow, Oxford * Mill Meado ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Headworks
Headworks is a civil engineering term for any structure at the head or diversion point of a waterway. It is smaller than a barrage and is used to divert water from a river into a canal or from a large canal into a smaller canal. at Web archive An example is the Horseshoe Falls at the start of the Llangollen Canal The Llangollen Canal () is a navigable canals of the United Kingdom, canal crossing the border between England and Wales. The waterway links Llangollen in Denbighshire, north Wales, with Hurleston in south Cheshire, via the town of Ellesmere, S .... Historically the phrase "headworks" derives from the traditional approach of diverting water at the start of an irrigation network and the location of these processes at the "head of the works". See also * List of barrages and headworks in Pakistan References Civil engineering Irrigation {{Civil-engineering-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrology
Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and drainage basin sustainability. A practitioner of hydrology is called a hydrologist. Hydrologists are scientists studying earth science, earth or environmental science, civil engineering, civil or environmental engineering, and physical geography. Using various analytical methods and scientific techniques, they collect and analyze data to help solve water related problems such as Environmentalism, environmental preservation, natural disasters, and Water resource management, water management. Hydrology subdivides into surface water hydrology, groundwater hydrology (hydrogeology), and marine hydrology. Domains of hydrology include hydrometeorology, surface-water hydrology, surface hydrology, hydrogeology, drainage basin, drainage-basin management, and water quality. Oceanography and meteorology are not included beca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pre-dam
A forebay is an artificial basin or pool of water situated upstream of a larger water body such as a reservoir, lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ..., or hydroelectric facility. It serves a variety of functions, including flow regulation, sediment capture, hydraulic buffering, and ecological enhancement. Functions Flood control and flow regulation Forebays act as holding basins during periods of intense rainfall or snowmelt. They slow the movement of water to prevent sudden surges into downstream reservoirs or urban drainage systems, thereby mitigating flood risk and protecting infrastructure. Sediment and debris management Forebays reduce water velocity, allowing sediment and debris to settle out before water enters a reservoir or treatment plant. This r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canal Locks
A lock is a device used for raising and lowering boats, ships and other watercraft between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a chamber in a permanently fixed position in which the water level can be varied. (In a caisson lock, a boat lift, or on a canal inclined plane, it is the chamber itself (usually then called a caisson (engineering), caisson) that rises and falls.) Locks are used to make a river more easily navigable, or to allow a canal to cross land that is not level. Over time, more and larger locks have been used in canals to allow a more direct route to be taken. History Ancient Egypt In Ancient Egypt, the river-locks was probably part of the Canal of the Pharaohs: Ptolemy II is credited by some for being the first to solve the problem of keeping the Nile free of salt water when his engineers invented the lock around 274/273 BC. Ancient China During 960–1279 CE, the natural extension o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
