Stidd (1967) used EOF to represent the seasonal
rainfall variations of rainfall over Nevada
and found that the first three terms in order of
importance account for 93% of the variance in
the original 12 60 matrix data and these have
features in common with the three natural cycles
of precipitation. Singh (1999) has also shown
the percentage of variance explained in different
categories of monsoon rainfall (normal, flood and
drought years) and concluded that the pattern has
the physical significance