Instantaneous Unit Hydrograph

Q. The ordinate of the instantaneous Unit Hydrograph (IUH) of a catchment at time t, is

1. the slope of the 1-hour unit hydrograph at that time
2. the slope of the direct runoff unit hydrograph at that time
3. difference in the slope of the S-curve and 1-hour unit hydrograph
4. the slope of the S-curve with effective rainfall intensity of 1 cm/hr

Q. Instantaneous unit hydrograph is a hydrograph of
(i) unit duration
(ii) unit rainfall excess
(iii) infinitely small duration
(iv) infinitely small rainfall excess

1. (i) and (ii)
2. (i) and (iv)
3. (ii) and (iii)
4. (iii) and (iv)

Q. The peak discharge of the instantaneous unit hydrograph of a basin, when compared to the peak discharge of a 4-hour unit hydrograph of the basin, would be

1. greater
2. equal
3. equal or lesser
4. lesser