Spatial Patterns and Temporal Trends of Rainfall Seasonality in Sri Lanka

Approximately half of Sri Lanka shows strong trends in rainfall seasonality, with 61% of the country experiencing a decreasing trend. This finding is significant for agricultural planning and water resource management. The study used the seasonality index (SI) to analyze rainfall data from 39 stations over 29 years, identifying distinct rainfall regimes such as 'equable with a definite wetter season' in the southwest and central highlands, and 'markedly seasonal with a long drier season' in the east and north. Non-parametric Mann-Kendall test and Sen’s slope were applied to detect temporal changes in SI, revealing notable variability across regions.

Amarasinghe, H. G. K. H., Basnayake, B. M. L. A.,. (2022). Spatial Patterns and Temporal Trends of Rainfall Seasonality in Sri Lanka. Proceedings of the SLIIT International Conference on Engineering and Technology, 272–278. https://doi.org/10.54389/qrsp2741