What Is The Optimum Number Of Rain Gauges

Many of us have the question in our mind that What is the Optimum Number Of Rain Gauges , so here is the answer explained in easy points .

1. It is the number of rain gauges required to calculate the average rainfall value with a certain                acceptable percentage (%) of error . This error represented by 'e%' .

2. For a catchment with n number of existing rain gauges having value P₁ P ₂ P₃ P₄ P ₅ P₆.................and        so on up to n terms . 

FORMULA FOR OPTIMUM NUMBER OF RAIN GAUGES 

It is calculated as follows :-

                                  N = (Cv/E)<sup>2

                   Here Cv = coefficient of variance</sup> 


                             
Hence additional number rain gauges required  = N - n