Harmonising the bioassessment of large rivers in the absence of near-natural reference conditions - a case study of the Danube River

2012 ◽  
Vol 57 (8) ◽  
pp. 1716-1732 ◽  
Author(s):  
SEBASTIAN BIRK ◽  
LEON van KOUWEN ◽  
NIGEL WILLBY
2016 ◽  
Vol 64 (4) ◽  
pp. 337-348 ◽  
Author(s):  
Veronika Bačová Mitková ◽  
Pavla Pekárová ◽  
Pavol Miklánek ◽  
Ján Pekár

Abstract The problem of understand natural processes as factors that restrict, limit or even jeopardize the interests of human society is currently of great concern. The natural transformation of flood waves is increasingly affected and disturbed by artificial interventions in river basins. The Danube River basin is an area of high economic and water management importance. Channel training can result in changes in the transformation of flood waves and different hydrographic shapes of flood waves compared with the past. The estimation and evolution of the transformation of historical flood waves under recent river conditions is only possible by model simulations. For this purpose a nonlinear reservoir cascade model was constructed. The NLN-Danube nonlinear reservoir river model was used to simulate the transformation of flood waves in four sections of the Danube River from Kienstock (Austria) to Štúrovo (Slovakia) under relatively recent river reach conditions. The model was individually calibrated for two extreme events in August 2002 and June 2013. Some floods that occurred on the Danube during the period of 1991–2002 were used for the validation of the model. The model was used to identify changes in the transformational properties of the Danube channel in the selected river reach for some historical summer floods (1899, 1954 1965 and 1975). Finally, a simulation of flood wave propagation of the most destructive Danube flood of the last millennium (August 1501) is discussed.


2017 ◽  
Vol 77 (2) ◽  
Author(s):  
Stefan Andjus ◽  
Nadja Nikolic ◽  
Valerija Dobricic ◽  
Ana Marjanovic ◽  
Zoran Gacic ◽  
...  

Sponges in the large rivers within the Danube River Basin (DRB) have not been adequately studied. Hence, the aim of this work was to undertake an investigation on the distribution of sponge species in the Danube and Sava rivers. Out of 88 localities covered by the study, sponges were found at 25 sites only (46 samples in total). By using morphological (light and scanning electron microscopy) and genetic (28S rDNA sequencing) analysis, four species were determined: Ephydatia fluviatilis (Linnaeus, 1759), Spongilla lacustris (Linnaeus, 1759), Eunapius fragilis (Leidy, 1851), Trochospongilla horrida Weltner, 1893. In the Danube, the predominant species was found to be E. fluviatilis making approximately 80% of collected samples, while in the Sava River S. lacustris dominated, representing 46% of the river sponges. Our work represents one of the few studies on freshwater sponges within the DRB from long stretches of the large lowland rivers (more than 2500 km of the Danube River and about 900 km of the Sava River). Moreover, molecular analysis for the identification of freshwater sponges was applied on the material collected from a wide area, thus contributing to the systematic studies on the distribution and abundance of the European freshwater invertebrate fauna in general.


2012 ◽  
Vol 38 (1) ◽  
pp. 49-61 ◽  
Author(s):  
Jovana Brankov ◽  
Dragana Milijašević ◽  
Ana Milanović

The Assessment of the Surface Water Quality Using the Water Pollution Index: A Case Study of the Timok River (The Danube River Basin), Serbia The Timok River (202 km long, 4547 km2 basin area) is located in East Serbia. It is a right tributary of the Danube River and one of the most polluted watercourses in Serbia. On the basis of the data provided by the Republic Hydrometeorological Service of Serbia, the paper presents an analysis of water quality and pollution using the combined physico-chemical WPI index (Water Pollution Index) calculated for two periods - 1993-96 and 2006-2009 at four hydrological stations: Zaječar-Gamzigrad (Crni Timok River), Zaječar (Beli Timok River), Rgotina (Borska Reka River) and Čokonjar (Timok River). The following parameters were taken into consideration: dissolved O2, O2 saturation, pH, suspended sediments, Five Day Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (CODMn), nitrites, nitrates, orthophosphates, ammonium, metals (Cu, Fe, Mn, Hg, Ni, Zn, Cd), sulphates and coliform germs. The average WPI values were calculated for the observed periods based on the comparison of the annual average values of the listed parameters and defined standard values for the I water quality class (according to the Regulation on the Hygienic Acceptability of Potable Water of the Republic of Serbia). The highest pollution degree was recorded in the Borska Reka River, where heavy metal levels (especially manganese and iron) were significantly increased. These metals are indicators of inorganic pollution (primarily caused by copper mining). Also, increased values of the organic pollution indicators (ammonium, coliform germs, Five-Day Biological Oxygen Demand - BOD5) in the Borska Reka and the Timok rivers are the result of uncontrolled domestic wastewater discharge.


2016 ◽  
Vol 571 ◽  
pp. 1370-1382 ◽  
Author(s):  
Andreu Rico ◽  
Paul J. Van den Brink ◽  
Patrick Leitner ◽  
Wolfram Graf ◽  
Andreas Focks

2014 ◽  
Vol 62 (3) ◽  
pp. 186-196 ◽  
Author(s):  
Veronika Bačová Mitková ◽  
Dana Halmová

Abstract The study is focused on the analysis and statistical evaluation of the joint probability of the occurrence of hydrological variables such as peak discharge (Q), volume (V) and duration (t). In our case study, we focus on the bivariate statistical analysis of these hydrological variables of the Danube River in Bratislava gauging station, during the period of 1876-2013. The study presents the methodology of the bivariate statistical analysis, choice of appropriate marginal distributions and appropriate copula functions in representing the joint distribution. Finally, the joint return periods and conditional return periods for some hydrological pairs (Q-V, V-t, Q-t) were calculated. The approach using copulas can reproduce a wide range of correlation (nonlinear) frequently observed in hydrology. Results of this study provide comprehensive information about flood where a devastating effect may be increased in the case where its three basic components (or at least two of them) Q, V and t have the same significance.


2018 ◽  
Vol 26 (4) ◽  
pp. 56-65
Author(s):  
Michaela Danáčová ◽  
Ján Szolgay

Abstract The Muskingum method is based on a linear relationship between a channel’s storage and inflow and outflow discharges. The applicability of using travel-time discharge relationships to model the variability of the K parameter in a Muskingum routing model was tested. The new parameter estimation method is based on the relationships between the traveltime parameter (K) and the input discharge for the reach of the Danube River between Devín-Bratislava and Medveďov, which includes the Gabčíkovo hydropower scheme. The variable parametrisation method was compared with the classical approach. The parameter X was taken as the average of its values from a small set of flood waves, K was estimated as a function of the travel-time parameter and discharge, which was optimized for one flood wave. The results were validated using the Nash-Sutcliffe coefficient on 5 floods. The results obtained by these methods were satisfactory and, with their use, one could reduce the amount of data required for calibration in practical applications.


Sign in / Sign up

Export Citation Format

Share Document