How does Rainfall happen? When water vapour bearing clouds condense to form droplets of water and spray it all over the landmass below. Have you ever heard "It rained 3 cm in Delhi today"? What does that mean? Rainfall is generally measured in terms of the height up to which it would fill an area if spread evenly over it. So, 3 cm rain over Delhi means that if all the rainwater that fell was kept stagnant over the whole of Delhi, it would form a layer of 3 cm height. 3 cm seems like a small amount, right? A rainfall of that magnitude over Delhi means a total volume of about 4,45,20,000 m3 (0.03m x 1484 km2) that is about 89,04,00,000 50 litre buckets. That's a huge amount, right?

Next Fact >>