On the other hand, Fig. 6.3 indicates the rainfall received in two groups of years. One line
describes the observed rainfall in all years between 1953 and 1990, while another line describes
a group of years that received lowest rainfall. Obviously the two lines are different – the “all
years” line indicates that the chance of receiving 1 100 mm is 88 percent, while the line
describing the rainfall amount for selected years (forecast distribution) indicates the chance
of receiving 1 100 mm is only 38 percent. This second line actually indicates that the chance of
receiving the amount of rainfall necessary for a successful crop season is comparatively lower.
Thus, in order to make an agricultural adjustment to manage cropping, it is important to
consider the forecast distribution as well as the “all years” line, because it indicates the higher risk
of drought. With the forecast line giving this extra information that an upcoming season will be
drier than normal, it is possible to advise farmers to initiate their drought management practices.