To derive the total flood hydrograph at a catchment outlet from an isolated storm, the order in which the following methods are applied, from the first method to the last method, is
P. Obtaining the hyetograph
Q. Addition of baseflow
R. Estimation of initial and infiltration losses
S. Application of unit hydrograph
A water resources project with an expected life of 25 years has to be designed for an acceptable risk of $5 \%$ against a design flood. The return period for the design flood (in years) is __________ (rounded off to the nearest integer).
The mean rainfall over a catchment has to be estimated. The data for four rain gauges located in and around the catchment is listed in the table. Which one of the following statements is correct:
$$ \begin{array}{|l|c|c|c|c|} \hline \text { Rain gauge station } & \text { P } & \text { Q } & \text { R } & \text { S } \\ \hline \text { Whether located inside the catchment } & \text { Yes } & \text { Yes } & \text { Yes } & \text { No } \\ \hline \text { Thiessen weightage factor } & 0.25 & 0.50 & 0.10 & 0.15 \\ \hline \text { Rainfall (mm) } & 100 & 110 & 100 & 125 \\ \hline \end{array} $$A symmetrical trapezoidal canal is 100 km long. The bottom width is 10 m and the side slope is 1 Horizontal : 1 Vertical. The average flow depth in the canal is 2.5 m throughout the month of April. The measurement from a Class-A evaporimeter in the vicinity of the canal indicated an average evaporation rate of $0.5 \mathrm{~cm} /$ day in April.
The volume of water evaporated from the canal (in $\mathrm{m}^3$ ) in the month of April is close to __________ $\times 10^3$ (rounded off to 1 decimal place).