This study assesses two drought indices; the Standardized Precipitation Index (SPI) and the Standardized Stream flow Index (SSI) at 12-month time scale. The major drought variables including: duration, severity and intensity were estimated. The indices are calculated by a parametric approach, which means the probability distribution is estimated for each month separately. The distributions are selected based on the Akaike Information Criterion and the EasyFit software. The parameters estimation was made using the maximum likelihood method. The joint behavior of drought characteristics and their long-term evolution in year was analyzed by the concept of Copula in the eastern part of Slovakia. Finally, the likelihood of moderate drought risk through joint return periods was evaluated.

This study presents a new multi-index hierarchical model for flood risk assessment which incorporates three indicator indexes—hazard, vulnerability, and exposure—to develop a five-level risk scale. The methodology is applied to historical data on flood events in The Slovak Republic between 2001 and 2010. The input values are characterized in more detail through the use of weighted values to provide a more balanced overall risk assessment. The original formula used to calculate the risk levels was found to produce results with overly high numerical values, and therefore the multiplication step of the formula was replaced by addition to insure greater simplicity and ease of use. This refined methodology introduces a novel quantitative approach to risk assessment, offering flexibility and variability in the indicator layer. The methodology can be adapted to assess risk at either the macro or micro scale and at more specific periods of time. The resulting risk values offer a nuanced understanding of risk levels across different indexes and underscores the method’s innovation.