Explain the stepwise procedure of estimating volume of reservoir from any contour map.
Reservoirs are made for water supply and for power or irrigation projects. A contour map is very useful to study the possible location of a dam and the volume of water to be confined. All the contours are closed lines within the reservoir area. The areas A1, A2, A3…..An between successive contour lines can be determined by a planimeter and if h is the contour interval, the capacity of the reservoir can be estimated by the application of either the trapezoidal or the prismoidal formula.