Rainfall And Measurement Of Rainfall.

It is a Principal form of precipitation, usually occurs in the form of water drops of sizes larger than 0.5 mm. On the basis of it's intensity, rainfall is classified as:

      Type                                                    Intensity
1.Light rain-                                              2.5mm/h                             
2.Moderate rain-                           
         2.5mm/h to 7.5mm/h
3.Heavy rain-                                            > 7.5mm/h


Measurement Of Rainfall 
Rainfall is usually measured by first collecting it in a rain gauge. These special drums are then used to record the depth of the water inside. Rain gauges are usually about 50 cm tall and are placed on the ground just high enough to avoid splashes.

Types of Rain Gauge.

Type 1 Non-recording gauge
            Rainfall level collected into collecting bottle is measured manually by suitably graduated measuring glass. the circular collecting bottle has standard area with (d=12.7 cm) e.g (Symon's type)

Type 2 Recording Gauge
            These Gauge produce a continuous  plot (graph) of rainfall against time.
  e.g
Tipping Bucket Type- Data can be obtained in digital form.

Weighing Bucket Type- This gives graph of accumulated rainfall against time. (mass curve of rainfall).

Natural Syphon Type (float type)- This is adopted in India as standard recording type rain gauge.

Telemetering Rain Gauge- These are mostly very useful in mountainous and generally inaccessible places.