Test: Hydrology - GATE MCQ

The number of revolution of a current meter is 50 seconds were found to be 12 and 30 corresponding to the velocities of 0.25 m/s and 0.46 m/s respectively. What velocity (in m/s) would be indicated by 50 revolutions of that current meter in 1 minute ?

(Important - Enter only the numerical value in the answer)

The probability that a 10 year return period flood will occur atleast once in the next 4 year is :

If the base period of a 6 hr unit hydrograph (UH) of a basin is 84 hours, then a 12 hr unit hydrograph derived from this 6 hr unit hydrograph will have a base period of :

A 6 hr storm has 6 cm of rainfall and the resulting runoff of 3 cm. If φ index remains at the same value,
which one of the following is the runoff due to 12 cm of rainfall in 9 hr in the catchment ?

Linked Questions 09 and 10

The drainage area of a watershed is 50 Km². The φ-index is 0.5 cm/hr and the base flow at the outlet is 10m³/s. One hour unit hydrograph of a watershed is triangular in slope with the time base of 20 hr. The 
peak ordinate occurs at 10 hours. 9.

Q. The peak ordinate (in m³/s) of the unit hydrograph is :

Linked Questions 09 and 10
The drainage area of a watershed is 50 Km². The φ-index is 0.5 cm/hr and the base flow at the outlet is 10m³/s. One hour unit hydrograph of a watershed is triangular in slope with the time base of 20 hr. The peak ordinate occurs at 10 hours. 

Q. For the storm of depth 6.5 cm and duration 1 hr, the peak ordinate (in m³/s) of the flood hydrograph is :

A 3 hour storm over a water shed had an average depth of 27mm. The resulting flood hydrograph was found to have a peak flow of 200 m³/s and a base flow of 20 m³/s. If the loss rate could be estimated as 0.3 cm/h, a 3-h unit hydrograph for this water shed will

The 3 hr unit hydrograph U₁ of a catchment of area 250 km² is in the form of a triangle with peak discharge of 40 m³/s. Another 3 hour unit hydrograph U₂ is also  triangular in shape and has the same base width as U₁ but with a peak flow of 80m³/s. The catchment which U₂ refers to has an area of :

The storm hydrograph was due to 3h of effective rainfall. It contained 6cm of direct runoff. The ordinates of DRH of this storm :

The basic assumptions of the unit hydrograph theory are :

Depth-Area-Duration curves of precipitations are drawn as :

The return period that a designs must use in the estimation of a flood for a hydraulic structure, if he is willing to accept 20% risk that the flood of that or higher magnitude will occur in the next 10 year, is

The standard project flood will generally be :

In a Linear reservoir, the

A reservoir with surface area of 250 hectares has saturation vapour pressure at water surface = 17.54 mm of Hg and actual vapour pressure of air = 7.02mm of Hg. Wind velocity at 1m above the ground surface = 16 km/hr. Estimate the average daily evaporation from the lake using Meysis formula……….mm/days.
(Take K_M = 0.36)

How is the average velocity along the vertical in a wide stream not obtained?

The intensity of rainfall time interval of a typical storm are :

The maximum intensity of rainfall for 20 minute duration of storm is:

The coefficient of variation of the rainfall for six rain gauge stations in a catchment was found to be 29.54% The optimum number of stations in the catchment for an admissible 10% error in the estimation of mean rainfall will be:

A 4hr storm had 4 cm of rainfall and the resulting direct runoff was 2 cm. If the φ-index remain at the same value, the runoff due to 10 cm of rainfall in 8 hr in the catchment is ?

Consider the following chemical emulsions :

1. Methyl Alcohol

2. Cetyl Alcohol

3. Stearye Alcohol

4. Kerosene

Which of the above chemical emulsions is/are used to minimize the loss of water through the process of evaporation ?

Which of the following defines Aridity Index (AI) ?

The average surface area of a reservoir in the month of June is 20 km². In the same month, the average rate of inflow is 10 m³/s, outflow rate is 15 m³/s, monthly rainfall is 10 cm, monthly seepage loss is 1.8 cm and the storage change is 16 million m³. The evaporation (in cm) in that month is: