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46-594: The town is divided into ten main quarters. They are Ohndaw Quarter 1, Ohndaw Quarter 2, Taungbyin Quarter 1, Taungbyin Quarter 2, Shwe-oh Quarter 1, Shwe-oh Quarter 2, Maungdaing Quarter 1, Maungdaing Quarter 2, Shwe Kya-in Quarter 1 and Shwe Kya-in Quarter 2. At the center of the town are the Myoma Zay central market, and the Independence Park. The Kandawgyi Lake , which used to be a weir in ancient times,

92-402: A fuse plug . If present, the fuse plug is designed to wash out in case of a large flood, greater than the discharge capacity of the spillway gates. Although many months may be needed for construction crews to restore the fuse plug and channel after such an operation, the total damage and cost to repair is less than if the main water-retaining structures had been overtopped. The fuse plug concept

138-443: A baffle of concrete blocks but usually have a "flip lip" and/or dissipator basin, which creates a hydraulic jump , protecting the toe of the dam from erosion. Stepped channels and spillways have been used for over 3,000 years. Despite being superseded by more modern engineering techniques such as hydraulic jumps in the mid twentieth century, since around 1985 interest in stepped spillways and chutes has been renewed, partly due to

184-424: A change in the height of the river level. Weirs are also used to control the flow of water for outlets of lakes, ponds, and reservoirs. There are many weir designs, but commonly water flows freely over the top of the weir crest before cascading down to a lower level. There is no single definition as to what constitutes a weir. Weir can also refer to the skimmer found in most in-ground swimming pools, which controls

230-463: A few dams lack overflow spillways and rely entirely on bottom outlets. The two main types of spillways are controlled and uncontrolled. A controlled spillway has mechanical structures or gates to regulate the rate of flow. This design allows nearly the full height of the dam to be used for water storage year-round, and flood waters can be released as required by opening one or more gates. An uncontrolled spillway, in contrast, does not have gates; when

276-488: A negative effect on fish species that migrate as part of their breeding cycle (e.g., salmonids ), but it also can be useful as a method of preventing invasive species moving upstream. For example, weirs in the Great Lakes region have helped to prevent invasive sea lamprey from colonising farther upstream. Mill ponds are created by a weir that impounds water that then flows over the structure. The energy created by

322-565: A plunge pool, or two ski jumps can direct their water discharges to collide with one another. Third, a stilling basin at the terminus of a spillway serves to further dissipate energy and prevent erosion. They are usually filled with a relatively shallow depth of water and sometimes lined with concrete. A number of velocity-reducing components can be incorporated into their design to include chute blocks, baffle blocks, wing walls, surface boils, or end sills. Spillway gates may operate suddenly without warning, under remote control. Trespassers within

368-415: A range of biota , including poor swimmers. Even though the water around weirs can often appear relatively calm, they can be extremely dangerous places to boat, swim, or wade, as the circulation patterns on the downstream side—typically called a hydraulic jump —can submerge a person indefinitely. This phenomenon is so well known to canoeists, kayakers, and others who spend time on rivers that they even have

414-416: A rueful name for weirs: "drowning machines". The Ohio DNR recommends that a victim should "tuck the chin down, draw the knees up to the chest with arms wrapped around them. Hopefully, conditions will be such that the current will push the victim along the bed of the river until swept beyond the boil line and released by the hydraulic." The Pennsylvania State Police also recommends to victims, "curl up, dive to

460-419: A spillway to regulate downstream flow—by releasing water in a controlled manner before the reservoir is full, operators can prevent an unacceptably large release later. Other uses of the term "spillway" include bypasses of dams and outlets of channels used during high water, and outlet channels carved through natural dams such as moraines . Water normally flows over a spillway only during flood periods, when

506-449: A weir is broad-crested for much of its length, but has a section where the weir stops or is 'open' so that small boats and fish can traverse the structure. A notch weir is any weir where the physical barrier is significantly higher than the water level except for a specific notch (often V-shaped) cut into the panel. At times of normal flow all the water must pass through the notch, simplifying flow volume calculations, and at times of flood

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552-405: Is a flat-crested structure, where the water passes over a crest that covers much or all of the channel width. This is one of the most common types of weir found worldwide. A compound weir is any weir that comprises several different designs into one structure. They are commonly seen in locations where a river has multiple users who may need to bypass the structure. A common design would be one where

598-473: Is a generic relationship and specific calculations are available for the many different types of weir. Flow measurement weirs must be well maintained if they are to remain accurate. The flow over a V-notch weir (in ft /s) is given by the Kindsvater–Shen equation: where As weirs are a physical barrier, they can impede the longitudinal movement of fish and other animals up and down a river. This can have

644-557: Is also a major product of the town. Taungdwingyi is connected to Magway (68 km (42 mi)) to the West, Pyay (162 km (101 mi)) to the South and Naypyidaw (68 km (42 mi)) to the East, by means of territorial roads and railways. By the territorial roads, it is 227 km (141 mi) to Mandalay and 365 km (227 mi) to Yangon . The closest major airport

690-420: Is classified as a tropical monsoon (short dry season, monsoon rains other months), with a subtropical dry forest biozone . The soil in the area is high in nitosols, andosols (nt), soil with deep, clay-enriched lower horizon with shiny ped surfaces. Weir A weir / w ɪər / or low-head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in

736-460: Is designed like an inverted bell , where water can enter around the entire perimeter. These uncontrolled spillways are also called morning glory (after the flower ), or glory hole spillways. In areas where the surface of the reservoir may freeze, this type of spillway is normally fitted with ice-breaking arrangements to prevent the spillway from becoming ice-bound. Some bell-mouth spillways are gate-controlled. The highest morning glory spillway in

782-559: Is located on the east side, and is ringed by a number of historic Buddhist monasteries . Zeya Mingala Shweindaung is the most sacred pagoda in the township. The Aung Myin Zeya Rakhine Pagoda located at the western part of the town is the largest pagoda in the township. Once, it was in a state of decay and renovation was finished in 2013. Economic of this town is based on agriculture and trading agricultural products. Onion, rice, beans, grains, and sugarcane are grown. Peanut oil

828-443: Is set by dam safety guidelines, based on the size of the structure and the potential loss of human life or property downstream. The United States Army Corps of Engineers bases their requirements on the probable maximum flood (PMF) and the probable maximum precipitation (PMP). The PMP is the largest precipitation thought to be physically possible in the upstream watershed. Dams of lower hazard may be allowed to have an IDF less than

874-1045: Is the Magway Airport (MWQ). The Taungdwingyi region is one of the earliest inhabited regions in Myanmar. The Pyu city of Beikthano was founded around 200 BCE . In 1278, a member of the Pagan royalty , Thihapate reestablished Taungdwingyi. In 1480, King Minkhaung II sent Lord Zeya Kyawhtin to administer the town. During the Ava period (1364–1555), the region produced a number of famous poets and writers such as Shin Ohnnyo , Shin Khayma , Shin Uttama and Shin Maha Thilawuntha , Shin Nyeinme and Khingyi Phyaw . April

920-604: Is used where building a spillway with the required capacity would be costly. A chute spillway is a common and basic design that transfers excess water from behind the dam down a smooth decline into the river below. These are usually designed following an ogee curve . Most often, they are lined on the bottom and sides with concrete to protect the dam and topography. They may have a controlling device and some are thinner and multiply-lined if space and funding are tight. In addition, they are not always intended to dissipate energy like stepped spillways. Chute spillways can be ingrained with

966-408: Is warmest with an average temperature of 39 °C (102 °F) at noon. January is coldest with an average temperature of 14 °C (57 °F) at night. Temperatures drop sharply at night. January is on average the month with most sunshine. The wet season has a rainfall peak around August, the dry season is around the month of March. Taungdwingyi has a humid (> 0.65 p/pet) climate. The climate

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1012-463: The PMF. As water passes over a spillway and down the chute, potential energy converts into increasing kinetic energy . Failure to dissipate the water's energy can lead to scouring and erosion at the dam's toe (base). This can cause spillway damage and undermine the dam's stability. To put this energy in perspective, the spillways at Tarbela Dam could, at full capacity, produce 40,000 MW; about 10 times

1058-502: The bottom, and swim or crawl downstream". As the hydraulic jump entrains air, the buoyancy of the water between the dam and boil line will be reduced by upward of 30%, and if a victim is unable to float, escape at the base of the dam may be the only option for survival. There are many different types of weirs and they can vary from a simple stone structure that is barely noticeable, to elaborate and very large structures that require extensive management and maintenance. A broad-crested weir

1104-407: The capacity of its power plant. The energy can be dissipated by addressing one or more parts of a spillway's design. First, on the spillway surface itself by a series of steps along the spillway (see stepped spillway ). Second, at the base of a spillway, a flip bucket can create a hydraulic jump and deflect water upwards. A ski jump can direct water horizontally and eventually down into

1150-501: The change in height of the water can then be used to power waterwheels and power sawmills, grinding wheels, and other equipment. Weirs are commonly used to control the flow rates of rivers during periods of high discharge. Sluice gates (or in some cases the height of the weir crest) can be altered to increase or decrease the volume of water flowing downstream. Weirs for this purpose are commonly found upstream of towns and villages and can either be automated or manually operated. By slowing

1196-505: The crest of an overflow spillway on a large dam may therefore be referred to as a weir. Weirs can vary in size both horizontally and vertically, with the smallest being only a few centimetres in height whilst the largest may be many metres tall and hundreds of metres long. Some common weir purposes are outlined below. Weirs allow hydrologists and engineers a simple method of measuring the volumetric flow rate in small to medium-sized streams/rivers or in industrial discharge locations. Since

1242-414: The design of a weir that ensure that fish can bypass the barriers and access upstream habitats. Unlike dams, weirs do not usually prevent downstream fish migration (as water flows over the top and allows fish to bypass the structure in that water), although they can create flow conditions that injure juvenile fish. Recent studies suggest that navigation locks have also potential to provide increased access for

1288-414: The difference in height between the intake and the outlet to create the pressure difference required to remove excess water. Siphons require priming to remove air in the bend for them to function, and most siphon spillways are designed to use water to automatically prime the siphon. One such design is the volute siphon, which employs volutes or fins on a funnel to form water into a vortex that draws air out of

1334-423: The flood is sometimes expressed as a return period . A 100-year recurrence interval is the flood magnitude expected to be exceeded on the average of once in 100 years. This parameter may be expressed as an exceedance frequency with a 1% chance of being exceeded in any given year. The volume of water expected during the design flood is obtained by hydrologic calculations of the upstream watershed. The return period

1380-585: The flow at outlets of lakes, ponds, and reservoirs. Spillway A spillway is a structure used to provide the controlled release of water downstream from a dam or levee , typically into the riverbed of the dammed river itself. In the United Kingdom, they may be known as overflow channels . Spillways ensure that water does not damage parts of the structure not designed to convey water. Spillways can include floodgates and fuse plugs to regulate water flow and reservoir level. Such features enable

1426-413: The flow of water pulled into the filtering system. The word likely originated from Middle English were , Old English wer , a derivative of the root of the verb werian, meaning "to defend, dam". The German cognate is Wehr , which means the same as English weir. Commonly, weirs are used to prevent flooding , measure water discharge, and help render rivers more navigable by boat. In some locations,

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1472-602: The geometry of the top of the weir is known and all water flows over the weir, the depth of water behind the weir can be converted to a rate of flow. However, this can only be achieved in locations where all water flows over the top of the weir crest (as opposed to around the sides or through conduits or sluices) and at locations where the water that flows over the crest is carried away from the structure. If these conditions are not met, it can make flow measurement complicated, inaccurate, or even impossible. The discharge calculation can be summarised as where However, this calculation

1518-423: The maximum height a species can jump or creates flow conditions that cannot be bypassed (e.g., due to excessive water velocity) effectively limits the maximum point upstream that fish can migrate. In some cases this can mean that huge lengths of breeding habitat are lost, and over time this can have a significant impact on fish populations. In many countries, it is now a legal requirement to build fish ladders into

1564-413: The rate at which water moves downstream even slightly, a disproportionate effect can be had on the likelihood of flooding. On larger rivers, a weir can also alter the flow characteristics of the waterway to the point that vessels are able to navigate areas previously inaccessible due to extreme currents or eddies . Many larger weirs will have construction features that allow boats and river users to "shoot

1610-428: The reservoir has reached its capacity and water continues entering faster than it can be released. In contrast, an intake tower is a structure used to control water release on a routine basis for purposes such as water supply and hydroelectricity generation. A spillway is located at the top of the reservoir pool. Dams may also have bottom outlets with valves or gates which may be operated to release flood flow, and

1656-411: The reservoir is controlled by the mechanical gates. In this case, the dam is not designed to function with water flowing over the top if it, either due to the materials used for its construction or conditions directly downstream. If inflow to the reservoir exceeds the gate's capacity, an artificial channel called an auxiliary or emergency spillway will convey water. Often, that is intentionally blocked by

1702-427: The river bottom) that reduces the water oxygen content and smothers invertebrate habitat and fish spawning sites. The oxygen content typically returns to normal once water has passed over the weir crest (although it can be hyper-oxygenated), although increased river velocity can scour the river bed causing erosion and habitat loss. Weirs can have a significant effect on fish migration . Any weir that exceeds either

1748-459: The river downstream. One parameter of spillway design is the largest flood it is designed to handle. The structures must safely withstand the appropriate spillway design flood (SDF), sometimes called the inflow design flood (IDF). The magnitude of the SDF may be set by dam safety guidelines, based on the size of the structure and the potential loss of human life or property downstream. The magnitude of

1794-414: The spillway are at high risk of drowning. Spillways are usually fenced and equipped with locked gates to prevent casual trespassing within the structure. Warning signs, sirens, and other measures may be in place to warn users of the downstream area of sudden release of water. Operating protocols may require "cracking" a gate to release a small amount of water to warn persons downstream. The sudden closure of

1840-424: The system. The priming happens automatically when the water level rises above the inlets. The ogee crest over-tops a dam, a side channel wraps around the topography of a dam, and a labyrinth uses a zig-zag design to increase the sill length for a thinner design and increased discharge. A drop inlet resembles an intake for a hydroelectric power plant, and transfers water from behind the dam directly through tunnels to

1886-410: The terms dam and weir are synonymous, but normally there is a clear distinction made between the structures. Usually, a dam is designed specifically to impound water behind a wall, whilst a weir is designed to alter the river flow characteristics. A common distinction between dams and weirs is that water flows over the top (crest) of a weir or underneath it for at least some of its length. Accordingly,

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1932-474: The use of new construction materials (e.g. roller-compacted concrete , gabions ) and design techniques (e.g. embankment overtopping protection). The steps produce considerable energy dissipation along the chute and reduce the size of the required downstream energy dissipation basin. Research is still active on the topic, with newer developments on embankment dam overflow protection systems, converging spillways and small weir design. A bell-mouth spillway

1978-515: The water level can rise and submerge the weir without any alterations made to the structure. A polynomial weir is a weir that has a geometry defined by a polynomial equation of any order n . In practice, most weirs are low-order polynomial weirs. The standard rectangular weir is, for example, a polynomial weir of order zero. The triangular (V-notch) and trapezoidal weirs are of order one. High-order polynomial weirs are providing wider range of Head-Discharge relationships, and hence better control of

2024-474: The water rises above the lip or crest of the spillway, it begins to be released from the reservoir. The rate of discharge is controlled only by the height of water above the reservoir's spillway. The fraction of storage volume in the reservoir above the spillway crest can only be used for the temporary storage of floodwater; it cannot be used as water supply storage because it sits higher than the dam can retain it. In an intermediate type, normal level regulation of

2070-546: The weir" and navigate by passing up or down stream without having to exit the river. Weirs constructed for this purpose are especially common on the River Thames , and most are situated near each of the river's 45 locks . Because a weir impounds water behind it and alters the flow regime of the river, it can have an effect on the local ecology . Typically, the reduced river velocity upstream can lead to increased siltation (deposition of fine particles of silt and clay on

2116-695: The world is at Hungry Horse Dam in Montana, U.S., and is controlled by a 64-by-12-foot (19.5 by 3.7 m) ring gate. The bell-mouth spillway in Covão dos Conchos reservoir in Portugal is constructed to look like a natural formation. The largest bell-mouth spillway is in Geehi Dam , in New South Wales, Australia, measuring 105 ft (32 m) in diameter at the lake's surface. A siphon uses

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