How many mL is heavy rainfall?
Heavy rain: Greater than 4 mm per hour, but less than 8 mm per hour. Very heavy rain: Greater than 8 mm per hour. Slight shower: Less than 2 mm per hour. Moderate shower: Greater than 2 mm, but less than 10 mm per hour.
How do you calculate rainfall over area?
Formula: Area (Length x Width) x Rainfall
- A = Length of the roof area.
- B = Width of the roof area.
- C= The amount of rainfall in inches.
- The formula is A x B x C = Water Volume.
How much water is in an inch of rain?
One inch of rain falling on 1 acre of ground is equal to about 27,154 gallons and weighs about 113 tons. An inch of snow falling evenly on 1 acre of ground is equivalent to about 2,715 gallons of water.
How do you calculate rain per square foot?
Amount of Rain Falling on Your Property
- 1 square foot = 144 square inches (12 x 12)
- 1 acre = 43,560 square feet or 6,272,640 square inches (43,560 x 144)
- 1 inch of rain falling on 1 square foot = 144 cubic inches (12 x 12 x 1)
What does 3mm of rain look like?
Rainfall is measured with a rain gauge. This one goes up to 12 cm or 120 mm, so 3 mm would just be a few drops at the bottom.
How heavy is 1mm rain?
Mathematically speaking, 1 mm of rain translates to 1 litre of water in a single metre square. Or, 140 mm rainfall can fill an average cricket stadium with 23.8 lakh litres of water!
How do you calculate surface water volume?
Take the dimensions of the footprint of your roof and convert them to inches. (So, a 50′ x 20′ roof is 600″ x 240″.) Multiply the roof dimensions by the number of inches of rainfall. (In this example, 600″ x 240″ x 1″ = 144,000 cubic inches of water.)
How do you calculate rainwater runoff?
Simple, straightforward methods of calculating runoff can tell you the amount of water that storms bring to the earth. For a given surface area such as a roof or yard, multiply the area by the inches of rainfall and divide by 231 to obtain the runoff in gallons.
What does 100 mm rainfall mean?
One millimeter of rainfall is the equivalent of one liter of water per square meter. The standard way of measuring rainfall or snowfall is the standard rain gauge, which can be found in 100-mm (4-in) plastic and 200-mm (8-in) metal varieties.
How do you calculate surface water drainage?
To calculate the volume of water that needs to be stored, multiply the amount of runoff from each drainage zone by 15. The runoff for each zone was in gallons per minute. Multiplying by 15 minutes leaves you with the amount of gallons to be stored.
How do you calculate surface water runoff?
Is 1 ml of rain a lot?
A rainfall total of 0.2 mm is quite a small amount of rain, and unlikely to have much impact on many activities. Therefore, days of rain greater than or equal to 1 mm, 10 mm, and 25 mm are often used as indicators of the number of “wet” days.