Rainfall Mechanisms

A raindrop is simply some air moisture condensed.

Generally, rainfall event is created based on three formation of saturation, condensation and rain drops.

"And it is He Who sends the winds as heralds of glad tidings, going before His Mercy (rain). Till when they have carried a heavy-laden cloud, We drive it to a land that is dead, then We cause water (rain) to descend thereon. Then We produce every kind of fruit therewith. Similarly, We shall raise up the dead, so that you may remember or take heed." (7:57- The Noble Qur'an)

 

"And We send the winds fertilizing (to fill heavily the clouds with water), then cause the water (rain) to descend from the sky, and We give it to you to drink, and it is not you who are the owners of its stores [i.e. to give water to whom you like or to withhold it from whom you like]" (15:22- The Noble Qur'an)

Ponding or Flooding?

Since the December 2007, floods and stormwater management has become an increasingly important topic in Malaysia. Recently, there is also increasing on the awareness of the implications of climate change on the hydrology as this region experienced a number of extreme local weather events.

Intense rainfall caused flash floods in various parts of the city and rural areas. However, there is also become a big questions either it is flooding, or just ponding? We can interpret that once there is heavy rain and the water reached about 30cm height is ponding which the water generally subsided within 1 hour or less. Floods occur when the ponding water subsided within six hours. Flood types can be classified by the speed with which they occur, the location where they occur, or the cause of the flood and can be natural or artificial.

Precipitation

It’s raining, it’s pouring,

    The old man’s snoring.

He got into bed

    And bumped his head

And couldn’t get up in the morning.(by MotherGoose)

Some say raining, some say rainfall, others say rainwater, then what is precipitation?

Either what word it is, this is very valuable source more than gold in your hand...

          In general rain is the water in the skies comes down to Earth, where it fills our lakes and rivers, recharges the underground aquifers, and provides drinks to plants and animals.It is created a renewable resource that moves in a cycle with neither beginning nor end. 

             The amount of precipitation that falls around the world may range from less than 0.1 inch per year in some deserts to more than 900 inches per year in the tropics. The driest spots on Earth is Lquique, Chile, where no rain fell for a period of 14 years. The wettest spot is Cherrapunji, Meghalaya State, India with 10,820mm rain falls on average in a year. By contrast, Malaysia receives enough precipitation during an average year of about 2,300 mm (93 inches) , with the heaviest period during the December-February monsoon season. In addition, few countries also receives enough precipitation with an average  rain per year around 1,400 mm in Japan, 1,200 across the USA and 650 mm in France.