Browse topic-based Hydrology practice sets.
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the double mass curve technique adopted to
estimate the missing data
obtain intensities of rainfall at various durations
to obtains the amount of storage needed to maintain a demand pattern
to check the consistency of data
None of the above
Correct Answer: D — to check the consistency of data
Explanation:
Explanation: The different type of curves and their application is given below in tabulated form: Type of Curve | Application
a mean annual runoff 1 m3/s from a catchment of area 10 km2 represents an effective rainfall of
10.0 cm
315.4 cm
100 cm
31.54 cm
150 cm
Correct Answer: B — 315.4 cm
Explanation:
Given: Runoff = 1 m3/sec Catchment area = 10 km2 Calculations: Effective rainfall = Mean Annual Rainfall = 1 m3/sec × 365 × 24 × 60 × 60 Catchment Area = 10 km2 = 10 × 106 m2 Effective rainfall =
A hydrograph is a plot of
Stream discharge against time
Rainfall intensity against time
Cumulative rainfall against time
Cumulative runoff against time
None of the above
Correct Answer: A — Stream discharge against time
Explanation:
Concept: Hydrograph: A hydrograph is a plot between discharge and time at any given section of a river, channel, etc. It is a response of a given catchment to the rainfall input. The shape of the rising limb of a hydrograph depends on both catchment characteristics and rainfall characteristics.
The area between the isohytes 0.45 m and 0.55 m is 100 Sq.km and between 0.55 m and 0.65 m is of 150 Sq.km. The average depth of annual precipitation over the above basin of 250 Sq.km will be
0.50 m
0.55 m
0.56 m
0.60 m
1.0 m
Correct Answer: C — 0.56 m
Explanation:
Concept: Isohyetal method: The isohyetal method is used to estimate the mean precipitation across an area by drawing lines of equal precipitation. The method uses topographic and other data to yield reliable estimates. Isohyets are contours of equal precipitation analogous to contour lines on a topographic map.
Consider the factor affecting the evaporation losses:
The rate of evaporation increases as the wind speed decreases.
The rate of evaporation decreases with the increase in atmospheric pressure.
The rate of evaporation increases with an increase in salt concentration in water.
The rate of evaporation increases as the saturation vapor pressure increases.
Choose the incorrect statement:
1, 2
2, 3
1, 3
2, 4
Correct Answer: C — 1, 3
Explanation:
Concept: Evaporation losses: According to Daltons law: E = C (Es – Ea) C = a + bV a=b=constants. V=wind velocity in km/hr ES=Saturation vapor pressure at the water surface Ea=Actual vapor pressure. Factors Affecting Evaporation losses 1.
