A multidisciplinary and integrated approach to the flood mitigation decision making process should provide the best response of society in a flood hazard situation including preparation works and post hazard mitigation. In Slovenia, there is a great lack of data on social aspects and public response to flood mitigation measures and information management. In this paper, two studies of flood perception in the Slovenian town Celje are represented. During its history, Celje was often exposed to floods, the most recent serious floods being in 1990 and in 1998, with a hundred and fifty return period and more than ten year return period, respectively. Two surveys were conducted in 1997 and 2003, with 157 participants from different areas of the town in the first, and 208 in the second study, aiming at finding the general attitude toward the floods. The surveys revealed that floods present a serious threat in the eyes of the inhabitants, and that the perception of threat depends, to a certain degree, on the place of residence. The surveys also highlighted, among the other measures, solidarity and the importance of insurance against floods.

The paper presents a review of structural measures that were taken to cope with floods in some cities along the Danube River, such as Vienna, Bratislava, and Belgrade. These cities were also considered as case studies within the KULTURisk project. The structural measures are reviewed and compared to each other according to the type, duration of application, the return period of the design flood event, how the project measures are integrated into spatial planning and the problems that occur in the flood defences today. Based on this review, some suggestions are given on how to improve the flood risk management in flood-prone areas.

Floods not only induce vast economic damages but also pose a great danger to human life. In Slovenia, floods rank number one on the scale of damage magnitude. Different factors external to the hazard of flooding influence the gravity and extent of the impacts. A comprehensive collection and analysis of the information related to the understanding of causative factors of human impacts can substantially contribute to the mitigation and the minimisation of fatalities and injuries. In this work, historical analysis was performed for flood fatalities in the years between 1926 and 2014, with 10 flood events that induced 74 casualties considered. A detailed collection and review on human impacts was made. Victims in cars have seemed to increase in recent years and rural areas tend to be more vulnerable and susceptible to having victims of flooding. With regards to gender, the majority of victims are male. The focus was on demographic aspects (age and gender) of fatalities and analysis of the circumstances of loss of life. Based on a description of the activities of victims during flood events and repetitive patterns, groups were made based on the type of flood fatality. Eight interviews were performed with rescuers and people who were affected by floods in order to obtain more extensive information on preventative measures, received help, and flood risk perception.

Drought indices are commonly used for detection, monitoring and evaluation of drought events. One of the most commonly used drought indices is the Standardized Precipitation Index (SPI). This paper presents the effect of theoretical distribution selection on SPI values, and the analysis of drought events for five selected meteorological stations in Slovenia. We found that the SPI on the annual time scale shows a similar pattern of occurrence of dry and wet periods at Ljubljana-Bežigrad, Novo mesto, and Trieste meteorological stations; something similar can be said for the Celje and Maribor-Tabor stations. The analysis of the correlations between the standardized data river discharge and precipitation data for the selected river basin of the River Pesnica shows the strongest correlation between the SPI-2 and standardized discharges.

In May 2014, extreme floods occurred in the lower Sava River basin, causing major damage, with catastrophic consequences. Based on the data gathered, the weather situation in Bosnia and Herzegovina's (BiH) Bosna River basin was analysed and the hydrological conditions were provided, including the results of the probability analysis of the size of the recorded precipitation and flow rates. According to the observed data, extremely high precipitation intensities produced specific discharges of 1.0 m³ s⁻¹ km⁻². A hydrological model of the Bosna River basin was developed using HBV light for the purposes of reconstructing and forecasting such events more effectively. All analyses confirmed that the May 2014 event was an extreme extraordinary event whose return period greatly exceeds 100 years. The study is the basis for further flood safety measures and flood forecast development in the Bosna River basin.

Various models were developed in the past to simulate different hydrological processes. However, discrepancies between simulated and observed values are still significant and pose a challenge to many researchers. Models contain many parameters that cannot be directly measured. The values of most of these parameters are determined in the calibration process conditioning the efficiency of such models. This paper introduces the use of the enhanced Gauss–Levenberg–Marquardt (GLM) procedure in combination with the singular value decomposition (SVD) and Tikhonov regularization to improve the process of hydrological model calibration. The procedure is tested on a freely available hydrological model using a synthetic dataset. Based on several efficiency measures, the GLM procedure, in combination with SVD and Tikhonov regularization, was found to provide efficient model history matching and almost perfect parameter calibration. Moreover, by comparing the results of the proposed procedure with the results of global evolutionary calibration procedures, it was found that the only calibration using the combined GLM procedure gave a perfect fit in low flows. Last but not least, the noise in the calculation results with the combined GLM method was practically the same in either the calibration or validation procedure, suggesting that only computational noise remained in the results.