The Thiessen mean value (in mm, up to one decimal place) of the rainfall is ______
Dupuit’s assumptions are valid for
A culvert is designed for a flood frequency of 100 years and a useful life of 20 years. The risk involved in the design of the culvert (in percentage, up to two decimal places) is ______
The total rainfall in a catchment of area 1000 km^{2} , during a 6 h storm, is 19 cm. The surface runoff due to this storm computed from triangular direct runoff hydrograph is $ 1\times10^8 $m^{3} . The $ \phi_{index} $ for this storm (in cm/h, up to one decimal place) is ______
The ordinates of a 2-hour unit hydrograph for a catchment are given as
The ordinate (in m^{3}/s) of a 4-hour unit hybrograph for this catchment at the time of 3 h would be _________
An effective rainfall of 2-hour duration produced a flood hydrograph peak of 200 m^{3}/s. The flood hydrograph has a base flow of 20m^{3}/s. If the spatial average rainfall in the watershed for the duration of strom is 2 cm and the average loss rate is 0.4 cm/hour, the peak of 2-hour unit hydrograph (in m^{3}/s-cm, up to one decimal place) is _____________
During a storm event in a certain period, the rainfull intensity is 3.5 cm/hour and the $\style{font-family:'Times New Roman'}{\mathrm\Phi}$ -index is 1.5 cm/hour. The intensity of effective rainfall (in cm/hour, up to one decimal place) for this period is _____________
The infiltration capacity of a soil follows the Horton's exponetial model, $\style{font-family:'Times New Roman'}{f=c_1+c_2e^{-kt}}$. During an experiment the inital infiltration capacity was observed to be 200 mm/h. After a long time the infiltration capacity was reduced to 25 mm/h. If the infiltration capacity after 1 hour was 90 mm/h. the value of the decay rate constant, k (in h^{-1} up to two decimal places) is ____________.
A catchment is idealized as a 25km × 25km square. It has five rain gauges, one at each corner and one at the center, as shown in the figure.
During a month , the precipitation at these gauges is measured as G_{1}=300 mm, G_{2}=285 mm, G_{3}=272 mm, G_{4}=290 mm and G_{5}=288 mm. The average precipitation (in mm, up to one decimal place) over the catchment during this month by using the Thiessen polygon method is _____________
The direct runoff hydrograph in response to 5 cm rainfall excess in a catchment is shown in the figure. The area of the catchment (expressed in hectares) is _________.
The type of flood routing (Group I) and the equation (s) used for the purpose (Group II) are given below.
Water table of an aquifer drops by 100 cm over an area of 1000 km^{2}. The porosity and specific retention of the aquifer material are 25% and 5%, respectively. The amount of water (expressed in km^{3}) drained out from the area is _________
The ordinates of a one-hour unit hydrograph at sixty minute interval are 0, 3, 12, 8, 6, 3 and 0 m^{3}/s. A two-hour storm of 4 cm excess rainfall occurred in the basin from 10 AM. Considering constant base flow of 20 m^{3}/s, the flow of the river (expressed in m^{3}/s) at 1 PM is _________
A tracer takes 100 days to travel from Well-1 to Well-2 which are 100 m apart. The elevation of water surface in Well-2 is 3 m below that in Well-1. Assuming porosity equal to 15%, the coefficient of permeability (expressed in m/day) is
In a catchment, there are four rain – gauge stations, P,Q,R, and S. Normal annual precipitation values at these stations are 780 mm, 850 mm, 920 mm, and 980 mm, respectively. In the year 2013, stations Q, R, and S, were operative but P was not. Using the normal ratio method, the precipitation at station P for the year 2013 has been estimated as 860 mm. If the observed precipitation at stations Q and R for the year 2013 were 930 mm and 1010 mm, respectively, what was the observed precipitation (in mm) at station S for that year ?
The 4-hr unit hydrograph for a catchment is given in the table below. What would be the maximum ordinate of the S-curve (in m^{3}/s) derived from this hydrograph ?
A hydraulic jump takes place in a frictionless rectangular channel. The pre-jump depth is y_{p}. The alternate and sequent depths corresponding to y_{p} are y_{a} and y_{s} respectively. The correct relationship among y_{p}, y_{a} and y_{s} is:
The relationship between porosity ($\eta $), specific yield (S_{y}) and specific retention (S_{r}) of an unconfined aquifer is:
A triangular gate with a base width of 2 m and a height of 1.5 m lies in a vertical plane. The top vertex of the gate is 1.5 m below the surface of a tank which contains oil of specific gravity 0.8. Considering the density of water and acceleration due to gravity to be 1000 kg/m^{3} and 9.81 m/s^{2} respectively, the hydrostatic force (in kN) exerted by the oil on the gate is _________.
In reservoirs with an uncontrolled spillway, the peak of the plotted outflow hydrograph
An isolated 3-h rainfall event on a small catchment produces a hydrograph peak and point of inflection on the falling limb of the hydrograph at 7 hours and 8.5 hours respectively, after the start of the rainfall. Assuming, no losses and no base flow contribution, the time of concentration (in hours) for this catchment is approximately
The Muskingum model of routing a flood through a stream reach is expressed as O_{2}=K_{0}I_{2}+K_{1}I_{1}+K_{2}O_{1} where K_{0},K_{1} and K_{2} are the routing coefficients for the concerned reach, I_{1} and I_{2} are the inflows to the reach, and O_{1} and O_{2} are the outflows from the reach corresponding to time steps 1 and 2 respectively. The sum of ,K_{0} K_{1} and K_{2} of the model is
A 1-h rainfall of 10 cm magnitude at a station has a return period of 50 years. The probability that a 1-h rainfall of magnitude 10 cm or more will occur in each oftwo successive years is:
An isohyet is a line joining points of
At a station, Storm I of 5 hour duration with intensity 2 cm/h resulted in a runoff of 4 cm and Storm II of 8 hour duration resulted in a runoff of 8.4 cm. Assume that the $?$-index is the same for both the storms.
The Φ-index (in cm/h) is:
The intensity of storm II (in cm/h) is:
The ratio of actual evapo-transpiration to potential evapo-transpiration is in the range
The top width and the depth of flow in a triangular channel were measured as 4 m and 1 m, respectively. The measured velocities on the centre line at the water surface, 0.2 m and 0.8 m below the surface are 0.7 m/s, 0.6 m/s and 0.4 m/s, respectively. Using two-point method of velocity measurement, the discharge (in m^{3}/s) in the channel is
Group I contains parameters and Group II lists methods/instruments.
The drainage area of a watershed is 50 km^{2}. The $\mathrm\phi$ index is 0.5 cm/hour and the base flow at the outlet is 10 m^{3}/s. One hour unit hydrograph (unit depth = 1 cm) of the watershed is triangular in shape with a time base of 15 hours. The peak ordinate occurs at 5 hours.
The peak ordinate (in m^{3}/s/cm) of the unit hydrograph is
For a storm of depth of 5.5 cm and duration of 1 hour, the peak ordinate (in m^{3}/s) of the hydrograph is
A watershed got transformed from rural to urban over a period of time. The effect of urbanization on storm runoff hydrograph from the watershed is to
The ordinates of a 2-h unit hydrograph at 1 hour intervals starting from time t=0, are 0,3,8,6,3,2 and 0 m^{3}/s. use trapzodial rule for numerical intergration, if required.
What is the catchment area represented by the unit hydrograph?
A storm of 6.6 cm occurs uniformly over the catchment in 3 hours if ∅ -index is equal to 2mm/h and base flow is 5 m^{3}/s, what is the peak flow due to the storm?
The correct match of Group-I with Group-II is
The depth of flow in an alluvial channel is 1.5 m. If critical velocity ratio is 1.1 and Manning’s n is 0.018, the critical velocity of the channel as per Kennedy’s method is
One hour triangular unit hydrograph of a watershed has the peak discharge of 60m^{3}/sec.cm at 10 hours and time base of 30 hours. The $\phi$ index is 0.4 cm per hour and base flow is 15 m^{3}/sec.
The catchment area of the watershed is
If these is rainfall of 5.4 cm in 1 hour, the ordinate of the flood hydrograph at 15^{th }hour is
A flood wave with a known inflow hydrograph is routed through a large reservoir. The outflow hydrograph will have
A stable channel is to be designed for a discharge of Q m^{3}/s with silt factor f as per Lacey’s method. The mean flow velocity (m/s) in the channel is obtained by
As per the Lacey’s method for design of a alluvail channels, identify the TRUE statement from the following:
An isolated 4-hour storm occurred over a catchment as follows
The $\mathrm\phi$ index for the catchment is 10 mm/h. The estimated runoff depth from the catchment due to the above storm is
Ordinates of a 1-hour unit hydrograph at 1 hour intervals, starting from time t = 0, are 0, 2, 6, 4, 2, 1 and 0 m^{3}/s.
Catchment area represented by this unit hydrograph is
Ordinate of a 3-hour unit hydrograph for the catchment at t= 3 hours is