Contour : Line joining points of equal elevation.
Prismoidal formula :
V =
1 [A1 + An + 4 (A2 + A4 +...... ) + 2 (A3 + A5 + ...)]
where V = Volume orcapicity of the reservior
A1 = Area enclosed by F.R.L. contour
A2, A3 , …. , An = Area enclosed by other successive contours
h = contour interval
Trapezoidal formula :
V = h [
+ A2 + A3 + An-1]
where V = Volume orcapicity of the reservior
A1 = Area enclosed by F.R.L. contour
A2, A3 , …. , An = Area enclosed by other successive contours
h = contour interval