List of top Water Resources Engineering Questions asked in GATE CE

A pump with an efficiency of 80% is used to draw groundwater from a well for irrigating a flat field of area 108 hectares. The base period and delta for paddy crop on this field are 120 days and 144 cm, respectively. Water application efficiency in the field is 80%. The lowest level of water in the well is 10 m below the ground. The minimum required horse power (h.p.) of the pump is _________ (round off to two decimal places).
Water is flowing in a horizontal, frictionless, rectangular channel. A smooth hump is built on the channel floor at a section and its height is gradually increased to reach choked condition in the channel. The depth of water at this section is \(y_2\) and that at its upstream section is \(y_1\). The correct statement(s) for the choked and unchoked conditions in the channel is/are
A flood control structure having an expected life of n years is designed by considering a flood of return period T years. When T = n, and n \to \infty, the structure’s hydrologic risk of failure in percentage is} _________ %. (round off to one decimal place)
Match Column X with Column Y:
Which one of the following combinations is correct?
In a certain month, the reference crop evapotranspiration at a location is 6 mm/day. If the crop coefficient and soil coefficient are 1.2 and 0.8, respectively, the actual evapotranspiration in mm/day is
A rectangular open channel of 6 m width is carrying a discharge of 20 m³/s. Consider the acceleration due to gravity as 9.81 m/s² and assume water as incompressible and inviscid. The depth of flow in the channel at which the specific energy of the flowing water is minimum for the given discharge will then be
A lake has a maximum depth of 60 m. If the mean atmospheric pressure in the lake region is 91 kPa and the unit weight of the lake water is 9790 N/m\(^3\), the absolute pressure (in kPa, round off to two decimal places) at the maximum depth of the lake is \(\underline{\hspace{2cm}}\).
A 12-hour unit hydrograph (of 1 cm excess rainfall) of a catchment is of a triangular shape with a base width of 144 hour and a peak discharge of 23 m\(^3\)/s. The area of the catchment (in km\(^2\), round off to the nearest integer) is \(\underline{\hspace{2cm}}\).

The hyetograph in the figure corresponds to a rainfall event of 3 cm. 

If the rainfall event has produced a direct runoff of 1.6 cm, the \(\phi\)-index of the event (in mm/hour, round off to one decimal place) would be \(\underline{\hspace{1cm}}\).

A venturimeter as shown in the figure (not to scale) is connected to measure the flow of water in a vertical pipe of 20 cm diameter. 

A reservoir with a live storage of 300 million cubic meters (1 hectare = \(10^4 \, \text{m}^2\)) of a crop with two fillings of the reservoir. If the base period of the crop is 120 days, the duty for this crop (in hectares per cumec, round off to integer) will then be \(\underline{\hspace{1cm}}\).
A fire hose nozzle directs a steady stream of water of velocity 50 m/s at an angle of 45° above the horizontal. The stream rises initially but then eventually falls to the ground. Assume water as incompressible and inviscid. Consider the density of air and the air friction as negligible, and assume the acceleration due to gravity as 9.81 m/s\(^2\). The maximum height (in m, round off to two decimal places) reached by the stream above the hose nozzle will then be \(\underline{\hspace{1cm}}\).
The ratio of the momentum correction factor to the energy correction factor for a laminar flow in a pipe is:
Is this incompressible or irrotational?
\(V = 3î + 5 xĴ\)