Module 1: Hydrologic Cycle
Lecture 2: Weather and hydrologic cycle (contd.)
 
Precipitation

Mean precipitation over an area

The following methods are used to measure the average precipitation over an area:

  1. Arithmetic Mean Method
  2. Thiessen polygon method
  3. Isohyetal method
  4. Inverse distance weighting
1. Arithmetic Mean Method

Simplest method for determining  areal average

where, Pi : rainfall at the ith raingauge station
             N :Total number of raingauge stations