The Hydrograph Tutorial 2

8.Total direct runoff at any time t,due to excess rainfall of equal duration D-h and value Ri(i = 1...m) and if the ordinate of unit hydrograph is u(t),can be estimated by :

1.Qt = summation of rainfall values multiplied by the unit hydrograph ordinate at time t-(i-1)D

2.Qt = summation of rainfall values multiplied by the unit hydrograph ordinate at time t-(i-1)

3.Qt = summation of rainfall values multiplied by the unit hydrograph ordinate at time (i-1)D

4.Qt = summation of rainfall values multiplied by the unit hydrograph ordinate at time (i-1)

9.Summation of Direct Runoff Hydrograph and Baseflow equals the Total flood runoff.

1.Yes

2.No

10.If the data of few isolated storms[1 to 4 cm(Excess Rainfall)] of nearly equal duration are available for a continuously gaged basin then ordinates of unit hydrograph of the basin can be predicted by :

1.Average of area of all the DRH divided by the 'Volume of direct runoff' per unit square of basin area

2.Average of area of all the DRH multiplied by the 'Volume of direct runoff' per unit square of basin area

3.Average of area of all the DRH divided by the 'Volume of direct runoff'

4.None of the above

11.Ordinate of unit hydrograph can also be represented by :

1.Avg of DRH/Avg of ER

2.DRH/ER

3.DRH*ER

4.(DRH-ER)/ER

where DRH = Direct Runoff Hydrograph,ER = Excess Rainfall.

12.The duration of unit hydrograph must not exceed 1/5 to 1/3 of basin lag.

1.Yes

2.No

13.If the area of a catchment is greater than 250 SqKm then the duration of Unit Hydrograph must not exceed 6 hr.

1.Yes

2.No

14.The unit hydrograph(u(t)) of a complex composite storm of different rainfall duration can only be obtained if the equation :

Qn = Multiplication of Excess Rainfall and ordinates of the unit hydrogaph is solved for each of the storm.

1.True

2.False