Rainfall and raingauges

Infiltration(F): This is the ground rainfall infiltrated by the soil

Infiltration Capacity(f): It is the maximum rate at which soil in a given condition can absorb water.

Rainfall Interception(Pi): It is rain interrupted by the buildings and the trees etc. 

                                 So Total rainfall = P-Pi

Depression Storage(Sd): None of this appears as the surface run-off.

Rainfall excess(Pe):  Simply it is Rainfall Rate(P) - Infiltration Capacity (f)

To measure the amount of rainfall, two types of rain gauges are used:

1.Non-recording type Rain-gauge : It only collects the rain. It is of the following types:

   (a) Symen's type   (b) Standard gauges adopted by Indian Meteorological Department(MID)

2. Recording type Raingauges: It gets recorded automatically on a graph paper. This gauge thus produces a record of cumulative rain vs. time in the form of a graph, which is called mass curve of rainfall. 

  (a) Tipping Bucket type   (b)Weighing type     (c) floating type etc.(most widely used in India)