Skip to main content

GATE questions from Hydrology - GATE PSUs preparation -part 10

Here are few statements from Hydrology which has made their place in GATE Civil Engineering(CE). The bold letter represents the answer which are absent in actual question.

  1. A linear reservoir is one in which storage varies linearly with outflow rate.
  2. When there is an increase in the atmospheric pressure, the water level in a well penetrating in a confined aquifer does not undergo any change.
  3. During a 6-hour storm, rainfall intensity was 0.8 cm/hour on a catchment of area 8.6 km^2. The measured runoff volume during this period was 2,56,000 m^3. The total rainfall that was lost due to infiltration, evaporation, and transpiration (in cm/hour) is 0.304.
  4. Vertical hydraulic conductivity of the top soil at certain is 0.2 cm/hr. A storm of intensity 0.5 cm/hr occurs over the soil for an indefinite period. Assuming surface drainage to be adequate, infiltration rate after the storm has lasted for a very long time, shall be 0.2 cm/hr.
  5. While applying Rational formula for computing design discharge, the rainfall duration is stipulated as the time of concentration because this leads to the largest possible rainfall intensity.
  6. The plan area of a reservoir is 1 km^2. Water level in the reservoir is observed to decline by 20 cm in a certain period. During this period, the reservoir  receives a surface inflow of 10 hectares-meters, and 20 hectares-meters are abstracted from the reservoir for irrigation and power. The pan evaporation and rainfall recorded during the same period at a near by meteorological station are 12 cm and 3 cm respectively. The calibrated pan factor is 0.7. The seepage loss from the reservoir during this period in hectare-meters is 4.6.
to be contd...

Popular posts from this blog

Comparison of Kennedy's and Lacey's Theories


Here is a brief comparison of Kennedy's theory and Lacey's theory for the design of channels for canal etc.

The concept of silt transportation is same in both the cases, both agree that the silt is carried by the vertical eddies generated due to friction of the flowing water against rough surface of canal. Kennedy considered a trapezoidal channel section and, therefore, he neglected eddies generated from the sides. For this reason, Kennedy's critical velocity formula was derived only in terms of depth of flow(y).  Lacey considered that an irrigation channel achieves a cup-shaped section(semi-ellipse) and that entire wetted perimeter of the channel contributes to the generation of silt supporting eddies. He, thus, used hydraulic mean radius(R) as a variable in his regime velocity formulas instead of depth(y).Kennedy stated all the channels to be in state of regime provided they did not silt or scour. But Lacey differentiated between two regime conditions, i.e. initia…

Fluid Mechanics- one liners- GATE preparation - part 2

Here is a list of one liners which can be useful for your Civil Engineering GATE examination.

1. The equation T= -(dP/dl).r/2 for flow through circular tubes, where T is shear stress at distance r from center, is applicable for both laminar and turbulent flow.
2. A fluid is a substance that can not remain at rest when subjected to a shearing force.
3. One end of a two dimensional water tank has the shape of a quadrant of a circle of radius 2m. When the tank is full, the vertical component of the force per unit length on the curved surface will be (pi = 3.14)
4. If mean velocities at two ends of a stream tube 10 cm apart are 2.5 m/sec and 3 m/sec then convectional tangential acceleration mid-way will be 13.75 m/sec^2.
5. When a particular discharge is flowing in a horizontal pipe, a mercury water U-tube manometer connected to entrance and throat of a Venturi-meter fitted in the pipe recorded a deflection of 25 cm. If the same discharge flowed through the same pipe kept at an i…

GATE, PSUs - Hydraulics, Irrigation, water resource Engg. notes - part 7

Hello there,
How have you been? Here is the 7th part of our notes for preparation of GATE and other examinations related to Civil Engineering.

As compared to gravity dams, earthen dams requires less skilled labor.The most suitable material for the central impervious core of a zoned embankment type dam is clay mixed with fine sand.Seepage through embankments in the earthen dam is controlled by drain trenches.Seepage through foundation in an earthen dam is controlled by providing impervious cut-off.The flow of water after spilling over the weir crest in chute spillway and side channel spillway respectively are at right angle and parallel to weir crest.The discharge passing over an Ogee spillway is given by CLH^(3/2) where, L is the effective length of spillway crest and H is the total head over the spillway crest including velocity head.Co-efficient of discharge of an Ogee spillway depends on depth of approach and upstream slop and also on downstream apron interference and downstream su…