Analysis of Drought Severity and Duration Using Copulas in Anuradhapura, Sri Lanka

A major drought event in Anuradhapura, Sri Lanka, characterized by 9 months of duration and a severity index of 10.95, was identified using advanced statistical modeling. The study employed copula-based joint distribution analysis to assess the interdependence between drought duration and severity, utilizing 3-month Standard Precipitation Index (SPI) data from 1951 to 2007. Frank copula was determined as the best-fit model for representing this relationship, combining gamma distributions for both variables. The research highlights the potential for preplanning and risk mitigation strategies by leveraging univariate and multivariate return periods of droughts, offering critical insights for managing agricultural vulnerabilities in drought-prone regions.

Ekanayake, E., & Perera, K. (2014). Analysis of Drought Severity and Duration Using Copulas in Anuradhapura, Sri Lanka. British Journal of Environment and Climate Change, 4(3), 312–327. https://doi.org/10.9734/bjecc/2014/14482