3. Data analysis and computing procedure
In the present study, the data for 68 stations spread
over a period of 41 years (1940±1980) has been
used. These stations represent the true rainfall
pattern over India. This study has been extended
to normal, flood and drought years of monsoon
rainfall over India. It is interesting to note that the
set of 68 stations selected for the monsoon total
has shown equally promising results for the all
India monsoon rainfall (June±September) as well
as annual rainfall series (Singh, 1994).
Parthasarthy had prepared a series from 306
well-distributed stations over the plain and hilly
regions for the period (1871±1988). Following
Parthasarthy (1987) flood year has been defined as
‡ S† or more and drought year …R À S† or less,…R
is the seasonal mean rainfall of 41 yearswhere R
period of the country as a whole and S is the
standard deviation. All the stations and years
considered in the present study have been tested