Probabilistic Risk Assessment of Meteorological and Hydrological Droughts with Copula Functions: A Multivariate Framework

Abstract Drought is a complex and gradually developing natural hazard with profound impacts on water resources, agriculture, and ecosystems. Its multifaceted nature, coupled with increasing frequency and severity under climate change, requires robust monitoring and risk assessment tools. Traditional univariate indices, such as the Standardized Precipitation Index (SPI), provide essential information on drought occurrence and intensity but cannot capture the interactions among hydroclimatic variables. Multivariate indices, including the Multivariate Standardized Drought Index (MSDI), address this limitation by integrating multiple variables, yet probabilistic characterization of drought characteristics remains…