A storm with a recorded precipitation of 11.0 cm, as shown in the table, produced a direct run-off of 6.0 cm. The $\emptyset$-index of this storm is ____________ cm/hr (rounded off to 2 decimal places).Time from start (hours) 1 2 3 4 5 6 7 8 Recorded cumulative precipitation (cm) 0.5 1.5 3.1 5.5 7.3 8.9 10.2 11.0
The $\emptyset$-index, also known as the infiltration index, is used to estimate the rate of infiltration during the period of a storm. It is calculated by dividing the volume of water infiltrated by the time over which the infiltration occurred.
Given:
- Total precipitation, $P=11.0\,cm$
- Direct runoff, $R=6.0\,cm$
The amount of infiltration, $F$, is given by:
$F=P-R=11.0-6.0=5.0\,cm$
We need to calculate the $\emptyset$-index over the entire duration of the storm, which is 8 hours. Therefore:
$\emptyset\text{-index}=\frac{F}{8\,hours}=\frac{5.0}{8}=0.625\,cm/hr$
Rounding off to 2 decimal places, the $\emptyset$-index is:
$0.63\,cm/hr$
This value does not fall within the provided range of 0.64 to 0.65. Verify calculations or conditions if there’s an expected range discrepancy.
Important Questions from Infiltration
The groundwater gets replenished by the seeping of water into the ground. This process is called
Which type of drainage system will collect the rainwater?
A contour of constant rainfall is known as
An artesian aquifer is the one where
- Which of the following is/are the infiltration index/indices?
