Climatic Zones of Sri Lanka under Changing Climate

Climate change is the major phenomenon and fundamental human development challenge ofthe 21st century. It is well known that all climatic regions in Sri Lanka have been experiencedwith severe climatic changes. As a result, entire flora and fauna including humans arevulnerable to these adverse consequences. In general, it is believed that nations wouldmitigate the climate change or adapt to the changing environments. For employment of suchmeasures, it is necessary to understand the macro-climatic region and their behavior under thechanging global climate. Based on the annual rainfall received, the country is divided mainlyinto four climatic zones: wet, intermediate, dry and arid. The climate of the country dependslargely on the monsoon wind patterns and series of temperature. Therefore, it is necessary tounderstand the climatic zones and their behavior to identify each climatic zone‟s minor andmajor climate changes. The main objective of this study was to study on macro-climatic regions of Sri Lanka underchanging climate. Therefore, the present study was carried out on macro-climatic regions ofthe island to find out the potential variation of temperature and rainfall patterns. Climatic datafor the 30 year period were collected from randomly selected metrological stations in eachclimatic zone and average temperature and rainfall data were analysed using least significantdifference (LSD) test. The results showed that average temperature of the country has increased 0.4° C from theyear 1869 to 1980. Kandy (intermediate zone) region shows the higher temperature after theyear of 1886 named as colonial era which was prevalent for deforestation and tea cultivation.A significantly increasing trend of temperature and decreasing trend of rainfall could beobserved entirely within wet zone, dry zone and intermediate zone in 20th century than 19thcentury. Findings reveal that the wet zone boundary has squeezed in and dry zone boundaryhas expanded in recent time. Such boundary movements of the zones are significantlyimportant on reclassification of the dry zone and intermediate zone. Therefore, further studieson climate regions of Sri Lanka under changing climate is needed to examine the relationshipbetween the vegetation cover distribution changes within the boundary of the climatic zones.Hence researchers could identify wet and intermediate zones as a “micro-climatic zones”while dry zone could be identified as a “macro-climatic zone” instead of traditionallygeneralised term in future. Keywords: Changing climate, Climatic zones, Macro-climatic region, Zone boundarymovement, Colonial er