Abstract:
Anuradhapura is one of the major agriculturally important districts located in the low
country dry zone of Sri Lanka and recently frequent crop failures were reported
owing to extreme climatic events such as droughts and floods. Although, many
researchers have investigated the climatic changes of the area during the past several
years, very few attempts can be seen on studying the extreme climatic events.
Therefore, the objective of this study was to analyze the occurrence of extreme
climate events in Anuradhapura district in Sri Lanka. Using daily minimum and
maximum temperature and precipitation data from 1981 to 2019, four extreme
temperature and six extreme precipitation indices which were defined by Expert
Team on Climate Change Detection and Indices (ETCCDI), were analyzed by
RClimeDex software package (Version 4.0.2). Simple linear regression was
performed to detect the significance of trends of extreme events. The number of very
heavy precipitation days (R20),number of days above 25mm (R25), very wet days
(R95p), extremely wet days (R99p), annual total wet days precipitation (PRCPTOT)
and simple daily intensity index (SDII) have increased during the study period, but
did not show a significant (P>0.05) trend. A significant (P<0.05) positive trend was
observed for warm nights (TN90p) and negative trends were observed for cool nights
(TN10p) and diurnal temperature range (DTR). Non-significant negative trend was
observed for warm days (TX90p) during 1981-2019 period. It can be concluded that
there is an increasing trend in the occurrence of extreme precipitation indices and
conspicuous changes in temperature indices during 1981-2019 period in
Anuradhapura district.
