scholarly journals The impact of large dams on fluvial sedimentation: The Iron Gates Reservoir on the Danube River

2021 ◽  
Vol 61 (1) ◽  
Author(s):  
Constantin Nistor ◽  
Ionuț Săvulescu ◽  
Bogdan-Andrei Mihai ◽  
Liliana Zaharia ◽  
Marina Vîrghileanu ◽  
...  
Keyword(s):  
Alluvial Fan ◽  
Danube River ◽  
Sediment Distribution ◽  
Ship Traffic ◽  
The Danube River ◽  
Spatial Changes ◽  
Before And After ◽  
Diachronic Analysis ◽  
Fluvial Sedimentation ◽  
The Impact

Dam construction is one of the major human pressures impacting fluvial processes, including topography and hydro-sedimentary flows, as a result of the change in flow regime from fluvial to fluvial-lacustrine. This article investigates geomorphic changes at Iron Gates I, the largest reservoir on the Danube River, completed in 1972 for hydropower and navigation. The study focuses on a gulf area that emerged at the mouth of the Cerna River into the reservoir, highlighting spatial changes in topography and sediment distribution, based on a diachronic analysis of two datasets before and after the dam was built: one extracted from historical topographic maps and the other obtained from a bathymetric echo sounding survey, integrated within a GIS analysis. The results reveal the dominance of the sedimentation process, with an alluvium layer thickness up to 14 m. The current sediment pattern has changed the submerged morphology, leading to the formation of an alluvial fan at the mouth of the Cerna River and of a sedimentary bar between the Cerna Gulf and the Danube River’s channel. The siltation process together with the current underwater morphology limits ship traffic and the storage capacity of the reservoir.

scholarly journals SENTINEL-1/2 DATA FOR SHIP TRAFFIC MONITORING ON THE DANUBE RIVER

2016 ◽  
Vol XLI-B8 ◽  
pp. 37-41
Author(s):  
I. Dana Negula ◽  
V. D. Poenaru ◽  
V. G. Olteanu ◽  
A. Badea
Keyword(s):  
Water Level ◽  
European Space Agency ◽  
Principal Component ◽  
Traffic Monitoring ◽  
Danube River ◽  
Ship Traffic ◽  
The Danube River ◽  
Space Agency ◽  
Free Data ◽  
Speckle Filtering

After a long period of drought, the water level of the Danube River has significantly dropped especially on the Romanian sector, in July-August 2015. Danube reached the lowest water level recorded in the last 12 years, causing the blockage of the ships in the sector located close to Zimnicea Harbour. The rising sand banks in the navigable channel congested the commercial traffic for a few days with more than 100 ships involved. The monitoring of the decreasing water level and the traffic jam was performed based on Sentinel-1 and Sentinel-2 free data provided by the European Space Agency and the European Commission within the Copernicus Programme. Specific processing methods (calibration, speckle filtering, geocoding, change detection, image classification, principal component analysis, etc.) were applied in order to generate useful products that the responsible authorities could benefit from. The Sentinel data yielded good results for water mask extraction and ships detection. The analysis continued after the closure of the crisis situation when the water reached the nominal level again. The results indicate that Sentinel data can be successfully used for ship traffic monitoring, building the foundation of future endeavours for a durable monitoring of the Danube River.

scholarly journals SENTINEL-1/2 DATA FOR SHIP TRAFFIC MONITORING ON THE DANUBE RIVER

2016 ◽  
Vol XLI-B8 ◽  
pp. 37-41 ◽  
Author(s):  
I. Dana Negula ◽  
V. D. Poenaru ◽  
V. G. Olteanu ◽  
A. Badea
Keyword(s):  
Water Level ◽  
European Space Agency ◽  
Principal Component ◽  
Traffic Monitoring ◽  
Danube River ◽  
Ship Traffic ◽  
The Danube River ◽  
Space Agency ◽  
Free Data ◽  
Speckle Filtering

After a long period of drought, the water level of the Danube River has significantly dropped especially on the Romanian sector, in July-August 2015. Danube reached the lowest water level recorded in the last 12 years, causing the blockage of the ships in the sector located close to Zimnicea Harbour. The rising sand banks in the navigable channel congested the commercial traffic for a few days with more than 100 ships involved. The monitoring of the decreasing water level and the traffic jam was performed based on Sentinel-1 and Sentinel-2 free data provided by the European Space Agency and the European Commission within the Copernicus Programme. Specific processing methods (calibration, speckle filtering, geocoding, change detection, image classification, principal component analysis, etc.) were applied in order to generate useful products that the responsible authorities could benefit from. The Sentinel data yielded good results for water mask extraction and ships detection. The analysis continued after the closure of the crisis situation when the water reached the nominal level again. The results indicate that Sentinel data can be successfully used for ship traffic monitoring, building the foundation of future endeavours for a durable monitoring of the Danube River.

Long Term Studies on the Impact of Thionic Bacteria on the Global Pollution of Waters with Toxic Ions

2009 ◽  
Vol 71-73 ◽  
pp. 105-108 ◽  
Author(s):  
Vladimir P. Beškoski ◽  
P. Papić ◽  
V. Dragišić ◽  
V. Matić ◽  
Miroslav M. Vrvić
Keyword(s):  
Ph Value ◽  
Copper Ions ◽  
Danube River ◽  
The Black Sea ◽  
Global Pollution ◽  
The Danube River ◽  
Copper Mineralization ◽  
Water Courses ◽  
Toxic Concentrations ◽  
The Impact

The biogeochemical activity of microorganisms from sulphide biogeocoenosis in the zones of sulphide copper ores deposits in East Serbia has been studied by us since 1975. All deposits of copper mineralization were dominantly sulphides and arsenic sulphides with the constant presence of pyrite. The obtained results proved that the biochemical and chemical activity of thionic bacteria have an influence on the global pollution of waters. All the waters were characterized by a low pH value and by high Eh values, mineralization (over 7 gL-1) and in total iron (even more than 4 gL-1) dominantly as Fe3+ ions. These waters were characterized by toxic concentrations of copper ions, within the limits from about 2 to almost 200 mgL-1 and arsenic, up to more than 4 mgL-1. These waters partly arrive in an aquifer and the major part flows into surface water¬ courses gravitating towards the Danube River, which empties into the Black Sea. In a hypothetical case, if maximum concentrations of copper and arsenic and maximum capacity of the springs are considered, under the assumption that the pollutants do not precipitate on the way to the main recipient, the striking information is obtained that the Danube River receives about 31 t of copper and more than 0.6 t of arsenic per annum from one place alone, which undoubtedly points to the contribution of thionic bacteria as "biological agents" to global pollution of surface and ground waters.

scholarly journals Diagnosis Of The Impact Of The Gabčíkovo Water Project On Soil Water Regime In The Surroundings

2014 ◽  
Vol 17 (2) ◽  
pp. 48-51
Author(s):  
Miroslava JARABICOVÁ ◽  
Mária PÁSZTOROVÁ ◽  
Justína VITKOVÁ ◽  
Peter MINARIČ
Keyword(s):  
Soil Water ◽  
Groundwater Level ◽  
Water Regime ◽  
Water Levels ◽  
Danube River ◽  
Soil Water Storage ◽  
Water Project ◽  
The Danube River ◽  
Soil Water Regime ◽  
The Impact

Abstract Rye Island is a unique natural formation, which lies between the main flow of the Danube River and the Little Danube River and is the largest river island in Europe. It is located in the southwest of Slovakia and with its mild to slightly warm climate is one of the most fertile agricultural areas in Slovakia. The whole Rye Island is also our greatest reservoir of quality waters used for drinking purposes, where groundwaters of Rye Island are permanently supplied with water from the Danube River. It means that as water levels in the Danube River were unstable before the construction of the Gabčíkovo Water Project, also the groundwater level faced large fluctuations. Changes occurred after putting the Gabčíkovo Water Project into service, with a decrease in groundwater levels. Thereby, the conditions for agriculture have improved and drying of surrounding protected floodplain forests has stopped. Through the present contribution we decided to analyse the impact of Gabčíkovo on soil water regime in the area of Rye Island, and evaluate the course of groundwater level, precipitation and soil water storage over time. For the representative area we chose a forest ecosystem of Král’ovská Lúka and evaluated the period 1999 to 2009.

scholarly journals Long-Term Changes of Species Composition and Functional Traits of Epiphytic Diatoms in the Szigetköz Region (Hungary) of the Danube River

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 776 ◽  
Author(s):  
Éva Ács ◽  
Tibor Bíró ◽  
Csaba Berta ◽  
Mónika Duleba ◽  
Angéla Földi ◽  
...  
Keyword(s):  
Common Species ◽  
Danube River ◽  
Water Volume ◽  
Anthropogenic Pressures ◽  
The Danube River ◽  
Core Species ◽  
Epiphytic Communities ◽  
Tributary System ◽  
The Impact

Here we report the results of our decades-long study on epiphytic communities from two tributary systems of the Szigetköz section of the Danube River. The main goal of the investigation was to detect changes in the epiphytic communities at structural (core species, changes in the relative abundance of common species) and functional (trait changes) levels as a result of the most important anthropogenic effects on Szigetköz, i.e., hydro-morphological modifications. We also examined the impact of rehabilitation on the tributary systems in terms of ecological potential. We discovered that mainly motile diatom species characterized the epiphyton due to reduced water volume were introduced into the tributary system after the diversion of the Danube. The ecosystem stabilized in the rehabilitated section, while the non-rehabilitated section showed a worsening tendency, mainly in the parapotamic branches. Our long-term data sets may provide a good basis for comparisons of different aquatic ecosystems, to define changes in the abundance of core species and in the structure of community in response to different anthropogenic pressures. It is fundamental to determine adaptive traits in assessing the impact of global warming stressors on biodiversity.

scholarly journals Prediction of Water Quality in the Danube River Under extreme Hydrological and Temperature Conditions

2009 ◽  
Vol 57 (1) ◽  
pp. 3-15 ◽  
Author(s):  
Pavla Pekárová ◽  
Milan Onderka ◽  
Ján Pekár ◽  
Peter Rončák ◽  
Pavol Miklánek
Keyword(s):  
Water Quality ◽  
Water Resources ◽  
Water Temperature ◽  
Danube River ◽  
The Danube River ◽  
Temperature Conditions ◽  
Water Quality Variables ◽  
Time Flow ◽  
The Impact

Prediction of Water Quality in the Danube River Under extreme Hydrological and Temperature ConditionsOne of the requirements imposed by the Water Framework Directive (WFD, 2000/60/EC) is to analyze and predict how quality of surface waters will evolve in the future. In assessing the development of a stream's pollution one must consider all sources of pollution and understand how water quality evolves over time. Flow and water temperature regime of a stream or river are the main factors controlling the extent to which deterioration of a stream's water quality can propagate under constant input from pollution sources. In addition, there is ever increasing public concern about the state of the aquatic environment. Decision makers and scientists involved in water management call for studies proposing simulation models of water quality under extreme natural hydrologic and climatic scenarios. Also, human impact on water resources remain an issue for discussion, especially when it comes to sustainability of water resources with respect to water quality and ecosystem health. In the present study we investigate the long-term trends in water quality variables of the Danube River at Bratislava, Slovakia (Chl-a, Ca, EC, SO2-, Cl-, O2, BOD5, N-tot, PO4-P, NO3-N, NO2-N, etc.), for the period 1991-2005. Several SARIMA models were tested for the long-term prediction of selected pollutant concentrations under various flow and water temperature conditions. In order to create scenarios of selected water quality variables with prediction for 12 months ahead, three types of possible hydrologic and water temperature conditions were defined: i) average conditions - median flows and water temperature; ii) low flows and high water temperature; and iii) high flows and low water temperature. These conditions were derived for each month using daily observations of water temperature and daily discharge readings taken in the Danube at Bratislava over the period 1931-2005 in the form of percentiles (1th-percentile, median, 99th-percentile). Once having derived these extreme-case scenarios, we used selected Box-Jenkins models (with two regressors - discharge and water temperature) to simulate the extreme monthly water quality variables. The impact of natural and man-made changes in a stream's hydrology on water quality can be readily well simulated by means of autoregressive models.

scholarly journals Genetic Diversity of Stellate Sturgeon in the Lower Danube River: The Impact of Habitat Contraction upon a Critically Endangered Population

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1115
Author(s):  
Daniela Nicoleta Holostenco ◽  
Mitică Ciorpac ◽  
Elena Taflan ◽  
Katarina Tošić ◽  
Marian Paraschiv ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Developmental Stages ◽  
Danube River ◽  
Critically Endangered ◽  
Genetic Structuring ◽  
The Danube River ◽  
Stellate Sturgeon ◽  
Loop Region ◽  
Increased Risk ◽  
The Impact

One of the last wild populations of the critically endangered stellate sturgeon (Acipenser stellatus) survives in the Danube River. Limited knowledge about the genetic structure, ecology, and evolution of this species led to poor and inconsistent management decisions with an increased risk for species extinction in the wild. Here we show the results of genetic structure screening of the Danube River wild population over 12 years timespan. Our research does not bring evidence of population recovery. No genetic structuring was identified at the mitochondrial level concerning spawning migration timing, sampling locations, and developmental stages. Eleven maternal lineages were revealed based on restriction fragment lengths analysis of the D-loop region, with one haplotype as the most frequent. While this could be the result of a massive restocking activity using a reduced number of spawners, our data does not support it. The selection of mitochondrial haplotypes under the pressure of habitat contraction and the narrower range of temperature variation since dams’ construction on the river could explain the observed distribution. Several factors of managerial concern are discussed. Our results provide baseline data on the mtDNA diversity in a critically endangered species of exceptionally high socioeconomic and conservation interest.

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