Abstract: The 1951-1999 measurements are employed to investigate in depth the climatic change features of yearly and seasonal disasters,arriving at the main results as follows:a) steady increase occurs in summer rainfall in contrast to reduction,to varying degree,in other seasons,particularly in autumn;b) the possibility is great (roughly 80%) for large-scale floods and/or droughts to be in the province on an annual basis. It is evident that the seasonal disasters hit the study region each year after 1985; c) the annual and seasonal calamities experience inter-decadal variation,and the climatic frequency of their occurrence shows noticeable change,especially in summer. The analyses from singular spectrum and maximum entropy spectrum techniques reveal that precipitation on a seasonal (summer and autumn) and an annual basis displays remarkable secular trend change with some 10-year periods found and,in contrast,about 2-year oscillations are particularly pronounced for the winter precipitation.