## Measurement: How to Measure the River Discharge?

For various purposes, the Measurement of River

*is required in Dam***Discharge****. It requires lot of Skill, Accuracy and***engineering***. To Measure the River Discharge, we require***Education*01) Area ofFlow

02) Average Velocity of Flow.

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*With this Data we can calculate*Discharge=Area of Flow X Average Velocity of Flow.

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*To Calculate Area of Flow, we can use following Methods*

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*A) Simple Segment Method*In thisMethod, the whole Width of River is divided into a number of Segment at Length, say L1,L2,L3 (Length of Segments) and at Depth say d1,d2,d3 (mean Depth of Segment).Now, the Area of Flow is Sum of all Area of Segments.(L1d1+L2d2+L3d3………………)

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*B) Simpsonâ€™s Rule*In thisMethod, the whole Width of River is divided into an even number of equal Segments, so that there is odd number of Depths taken at the end of each Segment.

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*02) Average Velocity of Flow*To Measure Average Velocity of

*following are three important Methods we can use.***Flow**A) FloatsB) Pitot Tube

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*A) Floats*With the help of Single Float, the Surface Velocity, at any section of River can be easilyobtained. For this we have to count time taken by the Float to Travel known Distance. The Velocity is Calculate by dividing the distanceÂ traveledÂ by the Float by the time taken to travel thatÂ distance.This Surface Velocity is then converted into an Average Velocity. To obtain Average Velocity directly, a Double Float or Rod Float is used.

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*01) Double Float*It consists of two Floats connected by a Wire or String. One Float is a Small Wooden Float, which Floats on Surface of River. Another is a Hallow Metallic Sphere which is heavier than Water is suspended from the former by a Wire or String, connecting the two Floats, in such that, the Lower Metallic Float is at Depth of 6/10 of the Total Depth of Flow, as the Average Velocity of Flow exists at a Depth of 6/10 to the Total Depth.The Velocity of Flow then Calculate by Dividing the distance traveled by the Float by the time taken to travel that distance. This Method Directly gives the Value of Average Velocity.

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*02) Rod Float*It consists of a Wooden Rod or a Metallic Rod Weighted at the bottom, so as to keep it Vertical or Inclined while travelling.The Length of the Rod is so adjusted that it should not touch the Weeds at bottom of the River and its top should be above the Water Surface. A Telescope Rod may be used to suitdifferentDepths. A section free from Weeds must be chosen to avoid possibilities of the Weeds at the bottom of River to Interface with Rod Float.ÂI hope above information will help you in measuring river discharge.If you have any knowledge about river discharge,please add it by comment.

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