HOW IS THE NUMBER OF LITERS CALCULATED DURING HEAVY RAIN? - ENVIRONMENT - 2025

The number of liters that falls during torrential rain is calculated in millimeters. To measure the amount of rainfall, an instrument called a rain gauge is used, which is usually found in meteorological stations.

To be precise, the number of liters of rain is calculated by multiplying the minutes that the torrential rain lasted by ¼ of the area used to measure.

Rain gauge, instrument for measuring falling water

For example, if the area to be measured is 4 m², and the rain fell for one hour. We make the calculation ¼ of 4 m² gives us 1 m²; one hour is 60 minutes; then 60 x 1 m² = 60L x m². But since the area to be measured is 4 m², the final calculation is 60 x 4 = 240 liters in total.

Calculation of the number of liters of water that falls during the rain in millimeters

As we said before, the world unit of measurement for rainfall is the millimeter. To measure in millimeters, the rain gauge is used, which accurately gives the amount of water that falls.

The rain gauge has a scale graduated in millimeters. Every millimeter in the rain gauge is equivalent to one liter per square meter.

That is, it is the amount of water that falls on an impermeable surface of one square meter during the time that the precipitation lasted.

Different classes of rain gauges

There are 4 different kinds of rain gauges:

Manual rain gauge

The manual rain gauge is the simplest indicator of rainfall. It is usually a special round container, it can be made of stainless steel or plastic, with a scale graduated in millimeters.

The height that the accumulated water reached is the amount of water that fell.

Totalizing rain gauges

The totalizing rain gauge consists of a funnel that collects the water in a graduated container.

It is placed at a certain height from the ground, and an operator will collect the information. As its name implies, it is used to measure the total amount of rain that has fallen in a certain period of time.

Siphon rain gauge

The siphon rain gauge is composed of a rotating drum that rotates at a constant speed, which in turn carries a graduated paper and a nib.

As the rain falls by the pen, it leaves marks on the paper. Time is recorded on the abscissa and the height of precipitation on the ordinate.

Tilting double bucket rain gauge

The double tipping bucket rain gauge has a funnel that guides the collected water into a small double bucket, triangular in shape, with a hinge at its midpoint.

The amount of falling water changes the balance in the buckets. These tilt and empty each time they are filled, to be filled again. They are emptied every 0.2 mm of precipitation, each bucket.

Rain classification

According to the intensity of the rain, this can be classified as

-Weak when it drops less than 2mm

-Moderate from 2.1 to 15 mm

-Strong from 15.1 to 30 mm

-Very strong from 30.1 to 60 mm

-Torrential more than 60 mm

There is also a designation for rainfall:

-Rain: most precipitation

-Drinking: Very weak rain

-Shower or shower: it is a moderate to strong rain, but of short duration

-Electric storm: it is a rain accompanied by electrical activity

-Monzón: it is a very intense and constant rain typical of areas with a very humid climate

-Water hose or waterspout: meteorological phenomenon of small dimensions, accompanied by intense wind in the form of a vortex.

References

1. «Do you know how rain is measured? in Córdoba Times (November 2013). Recovered in September 2017 from Córdoba Times: cordobatimes.com
2. "Rain" in Wikipedia. Retrieved in September 2017 from Wikipedia: es.wikipedia.org/
3. «How is the fallen rain measured? in NVI News (October 2010). Recovered in September 2017 from NVI Noticias: old.nvinoticias.com
4. "Analysis of precipitation intensity: Contiguous intensity method" in Time. Recovered in September 2017 from Time: tiempo.com.