What is the difference between a weir and barrage?
A weir is an impermeable barrier that is built across a river to raise the water level on the upstream side. On the other hand, a barrage involves adjustable gates installed over a dam to maintain the water surface at different levels and at different times.
What is a barrage balloon filled with?
A vital part of the UK air defences during the Second World War were barrage balloons. Large structures, about 19 metres long and eight metres in diameter, they were part-filled with hydrogen and deployed to altitudes of up to 5,000ft.
What is the job of a barrage?
A barrage is a type of low-head, diversion dam which consists of a number of large gates that can be opened or closed to control the amount of water passing through. This allows the structure to regulate and stabilize river water elevation upstream for use in irrigation and other systems.
What is the difference between a sluice and a weir?
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.
How does a weir and a barrage differ Mcq?
Explanation: Barrage is almost a similar structure like a weir, but the difference is that barrage is not a solid obstruction across a river and moreover the heading of the river is controlled by gates alone. The crest level in barrage is kept at low level. The body of this weir is kept as a low dam.
What is a barrage balloon How did it work?
A barrage balloon is a large uncrewed tethered balloon used to defend ground targets against aircraft attack, by raising aloft steel cables which pose a severe collision risk to aircraft, making the attacker’s approach more difficult. Early barrage balloons were often spherical.
How do barrage balloons work?
Barrage balloons worked as both a passive and active means of aerial defense. If an enemy aircraft was determined to attack, the balloons forced them to fly at higher altitudes (to fly over the balloons) making them more susceptible to larger caliber anti-aircraft gunfire.
What are the advantages and disadvantages of barrages?
Tidal Barrages
| Tidal Barrages | |
| Advantages No pollution Renewable Reliable No fuel costs, minimal running costs | Disadvantages Prevents free access by boat Spoils the view Alters habitat, affecting wildlife Initially expensive |
| Evaluation |
What’s the point of a weir?
Commonly, weirs are used to prevent flooding, measure water discharge, and help render rivers more navigable by boat. In some locations, the terms dam and weir are synonymous, but normally there is a clear distinction made between the structures.