A detonation pond has the shape of an inverted truncated pyramid, it has a rectangular bottom of dimension 120 ( 80 ft, a maximum depth of 5 ft, and uniform side slopes of 3 : 1 (horizontal : vertical). Hence the dimension at 5-ft depth are also rectangular, with length 150 ft and width 110 ft. The outlet from the basin behaves as an orifice, with a diameter of 1 ft and a discharge coefficient of 0.9. The opening of the orifice (a pipe draining from the center of the basin) is effectively at a depth of zero (i.e., at the bottom of the pond.) (The pond floor would typically slope toward the outlet but this lope will be ignored I this problem. In addition, the orifice will be assumed to follow its theoretical behavior even at every small depths).
a) What is the total volume of the pond, in ft' and ac-ft?
b) Develop the depth vs. surface area and depth vs. volume curves for the pond. Use 1-ft intervals. Tabulate and plot.
c) A triangular inflow hydrograph. Route it through the detention pond. The storage indication method (Puls method) of Section 4.3 is recommended, with a time step of 10 min. Plot the outflow hydrograph on the same graph as the inflow hydrograph?