Özet:

Due to recent climate changes and variability the frequency of occurrence and intensity of extreme climatic events such as flood, drought, etc. are increasing significantly in Sri Lanka. The main objectives of the study are to analyze the annual and seasonal rainfall variability in the last 147years from 1871-2018 with particular reference to drought and to assess the occurrence of droughts and its intensity and the impacts of drought on agriculture. For this secondary and primary data have been used. The long-term average annual rainfall of Mannar show the decreasing trend (r2= 0.0158), particularly in recent epochs higher negative anomalies of rainfall were found, as a results frequent occurrence of droughts or dry spells have been occurred. The rainfall anomaly results reveal that, out of 147years of the data period about 47years were experienced as drought and its probability is P=0.320. Accordingly, once in four to five years a drought could be possible. However, in the recent epoch of 1991-2018, higher number of droughts occurred than the any other epochs and its epochal probability is higher (P=0.40) than the normal, which indicate the effect of recent climate change.

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