Water Budget Method

Q. Calculate the runoff (cm) from a rainfall of 3 hours. The intensity of the rainfall is 2 cm/hr. The evaporation and infiltration losses are 8 mm and 16 mm.

1. 1.2
2. 2.8
3. 3.6
4. 6.8

Q. The average surface area of a reservoir in the month of June is 20 $k{m}^2$. In the same month the avg. rate of inflow is 10 $m^3/s$; out flow rate is 15 $m^3/s$, monthly rainfall is 10 cm, monthly seepage loss is 1.8 cm and storage change is 16 million $m^3$.
The evaporation (cm) in that month is:

1. 46.8
2. 136
3. 13.6
4. 23.4

Q. During a 6-hour storm the rainfall intensity was 0.8 cm/hr on a catchment of area $8.6k{m}^2$. The measured runoff volume during this period was $2,56,000m^3$. The total rainfall last due to infiltration, evaporation and transpiration in cm/hr is

1. 0.80
2. 0.304
3. 0.496
4. Sufficient information not available

Q.

Define the following.

Runoff water

Q. The plan area of a reservoir is $1k{m}^2$. The 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 ha-m and 20 ha-m are abstracted from the reservoir for irrigation and power. The pan evaporation and rainfall recorded during the same period at a nearby 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-m is

1. 0.0
2. 1.0
3. 2.4
4. 4.6

Q. Surface Runoff represents total water

1. flowing in surface channels after the rainfall.
   
2. Obtained after deducting from rainfall water what has infiltrated and/or evaporated, from the total rainfall.
3. excluding the base flow in surface channels after the rainfall.
4. flown (or flowing) through all channels over a specified period of time.

Q. The quantitative statement of the balance between water gains and losses in a certain basin during a specified period of time is known as which one of the following?
1. Water budget
2. Hydrologic budget
3. Ground water budget

Select the correct answer using the codes given below:

1. 1 only
2. 2 only
3. 3 only
4. none of these

Q. A small catchment of area 160 ha received a rainfall of 10.5 cm in 90 minutes due to a storm. At the outlet of the catchment, the stream draining the catchment was dry before the storm and experienced a runoff for 10 hours with an average discharge value of $2.5m^3/sec.$ The stream was again dry after the runoff event. The amount of water which was not available to runoff due to the combined effect of infiltration, evaporation and transpiration is ________ $m^3$.

1. 78000