What is a weir in a stream?
A weir is a small dam built across a body of water, such as a river. We use them to help control the flow of water. Weirs can help raise the water level so that boats can pass through, and they can also reduce the flow of water to prevent flooding.
What is a weir in a river?
A weir is a structure within a watercourse that impounds water upstream over a range of flows, over which water may flow. Weirs are a regular feature of British rivers and at least 13,000 weirs are known to exist in England and Wales alone.
What is weir and its types?
A weir is a concrete or masonry structure which is constructed across the open channel (such as a river) to change its water flow characteristics. Weirs are constructed as an obstruction to flow of water. These are commonly used to measure the volumetric rate of water flow, prevent flooding and make rivers navigable.
What is a weir in water treatment?
weir (WEER) A wall or plate placed in an open channel and used to measure the flow of water or to control flow (from settling tanks and clarifiers) to ensure a uniform flow rate and avoid short-circuiting.
What is weir and its function?
A weir /wɪər/ or low head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in 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.
How does a weir work?
A weir is a small barrier built across a stream or river to raise the water level slightly on the upstream side; essentially a small-scale dam. Weirs allow water to pool behind them, while allowing water to flow steadily over top of the weir.
What is spillway or weir?
A weir is an impervious barrier constructed across a river to raise the water level on the upstream side. The water is raised up to the required height and the water then flows over the weir. In a weir the water overflows the weir, but in a dam the water overflows through a special place called a spillway.
What is crest and sill?
The bottom edge of the notch or the top of a weir over which water flows is known as sill or crest. The height above the bottom of the tank or channel is known as crest height.
Why weir is provided?
Commonly, weirs are used to prevent flooding, measure water discharge, and help render rivers more navigable by boat.
What is Crest in weir?
The weir crest is the upstream element of a pair of boundary elements simulating a weir. The corresponding downstream element is the weir slope.
What is canal fall?
Canal fall is a solid masonry structure which is constructed on the canal if the natural ground slope is steeper than the designed channel bed slope. If the difference in slope is smaller, a single fall can be constructed. If it is of higher then falls are constructed at regular suitable intervals.
What is crest of weir?
What is Crest and sill?
What is broad crested weir?
The broad crested weirs are a hydraulic structures widely used for depth control and flow measurement in field and laboratory canals . The geometry described as a flat-crested structure with a length (L) of crest large enough compared to the flow thickness over the crest of the weir.
What is a Cipolletti weir?
Cipoletti Weir. A standard Cipoletti weir is trapezoidal in shape. The crest and sides of the weir plate are placed far enough from the bottom and sides of the approach channel to produce full contraction. The sides incline outwardly at a slope of 1 horizontal to 4 vertical.
What is end contraction of weir?
An end contraction is when the length of the weir (L) is less than the width of the Channel and a nappe contracts either one or both sides of the weir. The effective length of the weir in SWMM 5 is: L = Original Length – Number of End Contractions * Head over the Weir.
What is cross regulator?
A cross regulator is a structure constructed across a canal to regulate the water level in the canal upstream of itself and the discharge passing downstream of it for one or more of the following purposes: To feed offtaking canals located upstream of the cross regulator.
What is an in-stream Weir?
Weir is a low obstruction that is built across a river or canal to raise the water level, or in parallel to divert the water. Two types of weirs are used to control flow; an in-stream weir and a diversion weir. Low flows accumulate behind the in-stream weir, usually set across the flow, and pass through an orifice (opening)…
What is a weir?
On today’s episode, we’re talking about wiers. A weir is a small dam built across a river to control the upstream water level. Weirs have been used for ages to control the flow of water in streams, rivers, and other water bodies.
What happens to the water level behind an in stream Weir?
Low flows accumulate behind the in-stream weir, usually set across the flow, and pass through an orifice (opening) in the weir. As flows increase to the threshold flow rate, water levels behind the in-stream weir increase.
How do weirs control flow?
Two types of weirs are used to control flow; an in-stream weir and a diversion weir. Low flows accumulate behind the in-stream weir, usually set across the flow, and pass through an orifice (opening) in the weir. As flows increase to the threshold flow rate, water levels behind the in-stream weir increase.