How is rainfall rate measured?
The standard instrument for the measurement of rainfall is the 203mm (8 inch) rain gauge. This is essentially a circular funnel with a diameter of 203mm which collects the rain into a graduated and calibrated cylinder. The measuring cylinder can record up to 25mm of precipitation.
What is the velocity of rain water?
When all the parameters are considered the terminal velocity of a typical raindrop is calculated to be about 9 meters per second or 20 mph. A smaller raindrop of radius 0.15 cm has a terminal velocity of about 7 meters per second or 16 mph.
How many Litres is 1mm of rain?
With a rainfall of 1 mm, every square metre receives 1 litre of rain water. A rainfall of 1 mm supplies 0.001 m3, or 1 litre of water to each square metre of the field. Thus 1 ha receives 10 000 litres.
How do you calculate rainfall intensity from daily rainfall?
Compute the total rainfalls(tRF) in the year of 2016 by summing the values in dRF, i.e., tRF=dRF(1)+dRF(2)+… +dRF(366). Now find the intensity of rainfall(iRF) by dividing tRF by 366, that is iRF=tRF/366. This assumes that daily rainfall data is in mm units.
Do raindrops fall at constant velocity?
Rain drop falls with a constant velocity because the weight(which is the force of gravity acting on body) of the drop is balanced by the sum of the buoyant force and force due to friction(or viscosity )of air. Thus the net force on the drop is zero so it falls down with a constant velocity.
What is rain measured in units?
The most common rainfall measurement is the total rainfall depth during a given period, expressed in millimeters (mm). For instance, we might want to know how many millimeters of rain fell over the course of 1 h, 1 day, 1 month, or 1 year.