Flood Forecasting and Disaster Risk Management – a Case Study of Danube River

The Danube and its tributaries have been crossing mountains and plains in their almost unchanged riverbeds for thousands of years, regardless of national and administrative boundaries. Nevertheless, even decades ago, several countries provided access to only limited data and information concerning the water level and flood protection status of their rivers. In recent years, information was exchanged mainly on the basis of bilateral agreements and on successful activities of basin-wide organizations, but for others, information could only be obtained by browsing the Internet, which is sometimes rather complicated and definitely time-consuming. The EU Strategy for the Danube Region Environmental Risks Priority Area initiated a project aimed at developing the Danube Hydrological Information System, which was supported by the International Commission for the Protection of the Danube River. A comprehensive overview of the complex national flood and ice forecasting systems, identification of the shortcomings of the existing forecasting practices as well as an improvement of the exchange and availability of hydrological and meteorological data between the involved countries constituted crucial fields of interests for the project. Hence the main aim of the article is to present and discuss key data and functionalities of the system. The key findings show that all authorized meteorological and hydrological data of the Danube River are stored in a central database and made available online to all licensed hydrological and flood protection institutions for further processing in virtually real time. At this moment 12 countries of the Danube have joined forces to work out the proposals that are essential for the future, for safer Danube.

Multivariate Analysis of Water Quality Measurements on the Danube River

This study investigates the potential of using principal component analysis and other multivariate analysis techniques to evaluate water quality data gathered from natural watercourses. With this goal in mind, a comprehensive water quality data set was used for the analysis, gathered on a reach of the Danube River in 2011. The considered measurements included physical, chemical, and biological parameters. The data were collected within seven data ranges (cross-sections) of the Danube River. Each cross-section had five verticals, each of which had five sampling points distributed over the water column. The gathered water quality data was then subjected to several multivariate analysis techniques. However, the most attention was attributed to the principal component analysis since it can provide an insight into possible grouping tendencies within verticals, cross-sections, or the entire considered reach. It has been concluded that there is no stratification in any of the analyzed water columns. However, there was an unambiguous clustering of sampling points with respect to their cross-sections. Even though one can attribute these phenomena to the unsteady flow in rivers, additional considerations suggest that the position of a cross-section can have a significant impact on the measured water quality parameters. Furthermore, the presented results indicate that these measurements, combined with several multivariate analysis methods, especially the principal component analysis, may be a promising approach for investigating the water quality tendencies of alluvial rivers.

Videogrammetric Verification of Accuracy of Wearable Sensors Used in Kiteboarding

Owing to the combination of windsurfing, snowboarding, wakeboarding, and paragliding, kiteboarding has gained an enormous number of fans worldwide. Enthusiasts compete to achieve the maximum height and length of jumps, speed, or total distance travelled. Several commercially available systems have been developed to measure these parameters. However, practice shows that the accuracy of the implemented sensors is debatable. In this study, we examined the accuracy of jump heights determined by sensors WOO2 and WOO3, and the Surfr app installed on an Apple iPhone SE 2016, compared to a combination of videogrammetric and geodetic measurements. These measurements were performed using four cameras located on the shore of the Danube River at Šamorín, Slovakia. The videogrammetrically-determined accuracy of jump heights was 0.03–0.09 m. This can be considered a reference for comparing the accuracy of off-the-shelf systems. The results show that all of the systems compared tend to overestimate jump heights, including an increase in error with increasing jump height. For jumps over 5 m, the deviations reached more than 20% of the actual jump height.

Geological and geomorphological conditions of Archar-Orsoya lowland as a factor for the formation of groundwater chemical composition and in risk of its contamination

The Archar-Orsoya lowland is situated in the Danube floodplain west of the town of Lom, NW Bulgaria. It is aligned in a west-east direction along the Danube River and to the south it is bounded by a high landslide slope, built of Pliocene clays and sands. Parallel to the shore, sand dunes are formed with lowered sections between them, in which there are conditions for swamping. The lowland is made up of the alluvial sediments of the Danube, represented by a lower gravelly-sandy layer and an upper sandy-clayey layer. In the gravelly-sandy layer unconfined groundwater is accumulated, with shallow water table – from 0.5 to 7 m beneath the surface. Groundwater is recharged by infiltration of precipitation, surface water and groundwater, which laterally flows into the alluvium from adjacent aquifers. At high waters, the Danube River suppresses the formed groundwater flow and temporarily feeds it. Due to the described formation conditions in the lowland, the chemical composition of groundwater is formed under the influence of intense dynamics and has a low TDS (total dissolved solids). The shallow groundwater table and the corresponding thin unsaturated zone are a prerequisite for easy groundwater contamination with components entering from the surface. Therefore, a map of depth to groundwater table is drawn to identify the most vulnerable areas.

The symbolism of space in the novel the chronicle of the provincial theatre by Pavao Pavličić

The paper analyses the shaping of space in the novel The Chronicle of the Provincial Theatre by Pavao Pavličić. Postmodern giving priority to marginal categories is manifested in the following ways: national and world history reflect the life of the provincial town of Varoš; a theatre was built on the edge of the town close to the Danube River; the caretaker’s family lives in the theatrical building, whereby the boundaries of public and private space are wiped off; instead of the cultural heterotopia, the theatre of Varoš became an institution with numerous inartistic functions; the family and historical chronicle contains the elements of a detective novel (a stolen angel from the theatrical dome was being sought for almost a century, as long as the main character’s search for his personal identity lasted). Geographic figures form the symbolic layer of the novel: the theatre as a cultural and social figure of the mainland, the Danube River as a link with the countries of the Central and Eastern Europe and the aerial image which redefines the landscape of Varoš. Given these characteristics, Pavličić’s novel belongs to the variant of the new historical novel in Croatian literature.

Statistical Analysis and Trend Detection of the Hydrological Extremes of the Danube River at Bratislava

The territory of the Danube River Basin is one of the most flood-endangered regions in Europe. The flow regime conditions of the Danube River are continually changing. These changes are the result of natural processes and anthropogenic activities. In the present study, we focused on the statistical analysis and trend detection of the hydrological extremes of the Danube River at Bratislava. This paper firstly analyses the changes in correlation between water levels of the Danube River at Bratislava and Kienstock. Studied period of 1991-2013 included one or three hour measured water levels of the Danube River at Bratislava and Kienstock and shorter periods (1991–1995, 1999–2002, and 2004—2013) were selected for identification of the water level changes at Bratislava. One of the factors that recall the necessity to establish empirical - regression relationships was increasing of water levels of the Danube River at Bratislava (due to sediments accumulation at Bratislava). The results of the analysis indicated an increasing of water levels corresponding to the same flood discharges observed in the past. We also can say that travel time of the Danube floods between Kienstock and Bratislava did not change significantly during the analysed period. In the second part of the paper, we have identified changes in commonly used hydrological characteristics of annual maximum discharges, annual discharges and daily discharges of the Danube River at Bratislava during the period of 1876–2019. We examined whether there is a significant trend in discharges of the Danube River at Bratislava.