Question

Which of the following method does not give more than 3% error in the determination of the capacity of a reservoir?

(a) Prismoidal formula

(b) Trapezoidal method

(c) Average formula

(d) Integration method

I have been asked this question in an interview for job.

This intriguing question comes from Capacity and Area Elevation Curves of a Reservoir Site topic in chapter Reservoirs and Dam Reservoirs Planning of Irrigation Engineering

Answer 1

The correct option is (d) Integration method

The explanation is: The capacity of the reservoir can be determined by surveying only a few contours by using this method. When it is cross-checked with the capacity worked out by surveying a large number of contours this method gives less than 3% error. Since the areas of contours are not very precise figures this error is not considered much.