Abstract:
Historical and predicted rainfall records and spatial interpolation of temporal trends were analyzed to identify its
impact on major climatic zones of Sri Lanka. Data from GHCN version 2.0 of monthly precipitation from 1930 -
2000 of 15 gauging stations in Sri Lanka were used in this study. Annual and four temporal seasons: Southwest
monsoon (SWM), Northeast monsoon (NEM), First Inter-monsoon (FIM) and Second Inter-monsoon (SIM) were
used for the analysis. Regression models and the Mann-Kendall test were employed to build the linear and non linear long term annual and seasonal models. From 2001 to 2100, monthly rainfall values were simulated from
GCMs predictions by using LS-SVM. Then the annual and seasonal spatial distributions of trend statistics were
mapped by using the inverse distance weighted interpolation method (IDW). The results suggest that the current
boundaries of the wet zone of Sri Lanka have to be broadened and current intermediate zone could be expanded
further in the next century. A semi-arid region can be developed around Batticaloa and the eastern coastal belt of
the country. Current semi-arid regions may remain unchanged.
