The Flood in the Odra River 1997 – Impact of Suspended Solids on Water Quality

The flood in the Odra river in 1997 has led to considerable additional pollution of the Stettin Lagoon and the Baltic Sea with contaminated suspended solids. For some priority substances, the pollutant entries via suspended solids during the flood period are estimated to be approximately 1/3 of the usual annual load. Among these priority pollutants there are total organic carbon (TOC), nitrogen, and the heavy metals Cu, Pb and Zn. For the concentrations of the priority pollutants in suspended solids accumulation factors from 2 to 4 in the comparison with normal conditions were observed. On the basis of the analysis of sediments sampled after the flood, main sources of the pollutants should be evaluated. As reference area with an industrial background as well as a typical pollutant pattern the region around Glogow/Legnica is proposed.     

Phase Composition of Flood Sediments of the German-Polish Odra River Immediately after the Flood Event in 1997

Immediately after the flood event in summer 1997 at the Odra river, samples of flood sediments were taken for a complex phase analysis. The realized investigations show that the sampled flood sediments are very inhomogeneous. The main reasons for this substantial condition are surely different states of flow during the flood event. It is possible to characterize the investigated material as middle to fine sands with variable phase compositions. The mineral content of the fraction <2 μm shows a complex composition of amorphous matter, quartz, feldspars, and a different composed clay mineral matter. A high distribution of several mixed layers in the clay mineral phase is detectable. Within the scope of the taken analyses the following minerals were detected: kaolinite (disordered), kaolinite/smectite-mixed layer, chlorite/smectite-mixed layer, montmorillonite, illite/smectite-mixed layer, celadonite. The investigation of the heavy fraction shows heavy minerals and heavy particles of different geneses. Mainly these are geogenic, transparent heavy minerals like zircon, amphibole, garnet, pyroxene, apatite, rutile, and epidote. Furthermore there were analysed geogenic, opaque heavy minerals (magnetite and ilmenite), anthropogenic, opaque heavy particles (fly ashes and slags), and biogenic components (pyrite framboids). The substantial character of the investigated flood sediments (e.g. content of organic matter, content of clay minerals) shows that this material is able to act as a fixation medium of contaminants.     

Distribution of trace metals in the Odra River system: Water–suspended matter–sediments

Extensive investigations of trace metals concentrations in water, suspended particulate matter (SPM) and bottom sediments of the whole Odra River system were carried out over the years 1997–2000. The vertical distribution of selected metals and their mobility were also studied in the sediment cores from upper and middle river sections. Significant levels of metal contamination were found. Median concentrations (Cd, Pb, Cu, Zn and As) in the SPM and sediments were (mg kg⁻¹) 7.1 and 8.9 Cd, 128 and 146 Pb, 81 and 119 Cu, 1198 and 1204 Zn, 48 and 54 As, respectively. The highest metal pollution of the Odra River solids was found with cadmium, zinc, lead and arsenic, showing high similarity in their frequency distributions in both SPM and sediments. Cd, Zn and As appear to be of particular concern because of the high levels, that appear to be bioavailable, and their high mobility. The exchangeable and carbonate chemical forms of Cd and Zn reached up to 50% of their total amount. Besides the determination of total metal concentration, the metal chemical forms in river solids were investigated. The results of very wide studies of the Odra River system through 4 years suggest that metal pollution decreased, especially for Zn, Pb and Cu. Among all metals studied in the Odra River sediments, substantial reductions of Cd contamination were observed neither in the period after ’97 flood, nor if compared with the earlier results obtained before ’97. No essential differences of the metal contents were observed among the samples for the same river compartment, from the same locality, taken within the five sampling campaigns. The pattern of spatial and vertical metal distributions in the river solids indicates that a variety of sources might be responsible for the contamination; very intensive, historical and current mining and smelting activities probably are the most important ones.     

The Odra River Load of Heavy Metals at Hohenwutzen during the Flood in 1997

The Odra river flood of 1997 was a rare hydrological as well as an interesting sedimentological event. At Hohenwutzen (Lower Odra River) we observed the suspended particulate matter transport and the temporal development of water and solidsπ pollution with heavy metals and As. While the suspended particulate matter concentration decreased the trace element concentrations increased during the flood by fractionation of particles and solution processes. Because of a successive flooding of differently contaminated sedimentary sources and polluted regions the contents of heavy metals developed irregularly. Their median particulate concentrations did not exceed the values of older samples taken under mean discharge conditions between 1989 and 1995. The dissolved amounts correspond to those of the Elbe river in 1990. During the flood the dissolved share of all analyzed total element contents increased. The total loads increased 4fold (Cr) to 17fold (Cd).     

Investigations on Mineralogical and Chemical Composition of Suspended Particulate Matter (SPM) in the Odra Estuary

In order to recognize lateral and seasonal variations in composition of suspended particulate matter (SPM) in the Odra Estuary, samples were taken at four sites in the period July 1996 - July 1997 monthly if possible. The contents of the elements Si, Ti, Al, Fe, Mn, Mg, Ca, Na, K, P, C, S as well as Ba, Cr, Sr, V, Zn, Cu, Zr, and of the minerals illite, chlorite, smectite, kaolinite and others have been determined. The decreasing influence of the river Odra towards the open sea could be realized with the help of the contents of the minerals quartz, smectite, and of the elements Ba, Cr, K, P, Si and other. 60% of the seasonal and lateral variations can be explained by changing contents of total carbon (TC), total organic carbon (TOC), Al, Fe, Si, Ti, P, Mn, and Ba. They are mainly caused by differences in the production of organic matter, resuspension, riverine input, and redox-sensitive processes.     

Polycyclic Aromatic Hydrocarbons and Polysaccharides in River Sediments from the Odra Basin after the 1997 Flood

Fourteen polycyclic aromatic hydrocarbons (PAH), six monosaccharides (SA) formed following the hydrolysis of polysaccharides, as well as water and organic matter contents were determined in river sediments sampled in thirteen points in the Odra basin after the catastrophic flood of 1997. The water content is related to the water absorbing capacity of the soil in the Odra catchment area. The PAH content increases together with the increase in the organic matter (OM) content which suggests that these species are mainly of anthropogenic origin. On the other hand, SA and OM contents decrease with increasing water content, which implies that both enhance biological life. The PAH content tends to decrease when the SA content increases. This relation goes hand in hand with the quality of water resources, which is greater when the quantity of polysaccharides is higher.     

Study on changes in bed characteristics and friction factor in the presence of wash load in suspension

Results of an experimental study on the effects of different concentrations of wash load on the size of bed features and resistance to flow in a laboratory flume are presented. The experiments were carried out under different hydraulic conditions in a 30 m long, 0.204 m wide and 0.5 m deep tilting flume under clear water condition and in the presence of different concentration of wash load in the flow. The bed material used consisted of uniform sediment of size 0.96 mm. Analysis of the data indicates that the characteristics of the bed features change and friction factor increases in the presence of different concentration of wash load in the flow. The reasons for changes in the characteristics of the bed features and increase in friction factor in the presence of wash load are identified and a relationship for predicting friction factor in the presence of wash load has been established.     

Occurence and Transport of Organic Micro-contaminants in Sediments of the Odra River Estuarine System

Over ninety surface sediment samples (0...3 cm) were collected in the Odra river estuarine system – from the Oderhaff, the Pomeranian Bight, the Peenestrom, the Greifswald Bodden – and the Arkona Basin between 1994 and 1996 and analysed for polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/F) and biphenyls (PCB), and p,p′-dichlorodiphenyl-trichloroethane (DDT) including their metabolites. The contents of all investigated organochlorines in the sediments of the western part of the Oderhaff (Kleines Haff) were only slightly higher and more homogenously distributed compared to the values of the Pomeranian Bight and the Greifswald Bodden. PCB contents (sum of 23 congeners) in surface sediments ranged between <130 and 9 550 pg/g (given for dry weight, dw). The results of individual PCB congeners showed that high contents of hexa- and heptachlorinated compounds (PCB 138, 153, 180) were present in the entire area investigated. Generally, low levels of PCDD/F were found in surface sediments of the Odra river estuarine system due to small industrial activities in the catchment area. Contents of PCDF (sum) and PCDD (sum) varied from 2.5 to 820 pg/g (dw) and from 13 to 2 991 pg/g (dw), respectively. The congener contents of PCDF showed a nonuniform picture between the Oderhaff and the Arkona Basin. In contrast, the congener profiles of PCDD showed approximately similar patterns at nearshore and offshore stations, with highest values of OCDD (octa CDD). We assume that most of the particulate-bound micro-contaminants (PCB, PCDD/F) are deposited in the eastern part of the Oderhaff (Stettin Lagoon), which acts as a temporary trap and opurificationπ basin for the suspended particulate matter (SPM). One pathway for further transport of the particles seems to be the way on a small sedimentation strip along the island of Usedom via the “Saßnitz-trough” into the deeper parts of the western Baltic Sea.     

Point and Diffuse Nutrient Emissions and Transports in the Odra Basin and its Main Tributaries

The river Odra is one of the biggest transboundary rivers in Central Europe. The basin is characterized by an area of 110 074 km?sk (upstream Krajnik Dolny) and a population of about 15.5 million inhabitants. Compared with the Westeuropean river basins the specific runoff of the Odra basin is low and amounts only 4.5 L km?sk s–1. The long term changes of the average annual nutrient transport of the Odra at Krajnik Dolny show for the period 1991 to 1994 a low reduction for phosphorus but no changes for nitrogen. For the period of 1991 to 1994 an inventory of the point sources produces emissions of 10.7 kt a–1 P and 54.4 kt a–1 N upstream of the station Krajnik Dolny/Schwedt. Emissions from agricultural land and urban areas represent the main diffuse sources. A range of 68 to 96 kt a–1 N and 3.3 to 3.9 kt a–1 P were estimated for the total diffuse emissions depending on the database and the method of modeling. The emission situation of the river is characterized by a high dominance of point sources in the case of phosphorus (about 73%). For nitrogen the diffuse emissions dominate the total emissions to an amount between 59 and 67%. Compared to the emissions the nutrient transport is low. An average load of 5.1 kt a–1 P and 70.1 kt a–1 N was observed at the station Krajnik Dolny for the period 1991 to 1994. The emission and load situation within the main tributaries of the river Odra is comparable to the whole basin. The big difference between the total emissions and the observed load refers to intensive retention and loss processes within the river system of the Odra.     

Flood hazards in the upper and middle Odra River basin – A short review over the last century

During the 20th century many floods of different intensity and extent have occurred on the Odra River and its tributaries. On the basis of long-term water level observations five major floods, that affected the entire upper and middle Odra River basin, were chosen for further analysis: June 1902, July 1903, August 1977, August 1985 and July 1997. However, hazardous floods were not only those that covered the whole upper and middle Odra River basin, so several local floods were also studied. Detailed historical analysis was made of meteorological conditions, with special emphasis on precipitation patterns and amounts. Then, on the basis of flood peak time occurrence, the stages of flood wave formation were formulated. The natural flood wave of the Odra River is often modified by hydro-technical infrastructure, the development and improvement of which is briefly described in this paper. In conclusion, a comparison of flood wave characteristics such as rising time, falling time, duration, peak flow and volume is presented.     

Artificial neural network simulation for prediction of suspended sediment concentration in the River Ramganga,Ganges Basin,India

The relation between the water discharge (Q) and suspended sediment concentration (SSC) of the River Ramganga at Bareilly, Uttar Pradesh, in the Himalayas, has been modeled using Artificial Neural Networks (ANNs). The current study validates the practical capability and usefulness of this tool for simulating complex nonlinear, real world, river system processes in the Himalayan scenario. The modeling approach is based on the time series data collected from January to December (2008-2010) for Q and SSC. Three ANNs (T1-T3) with different network configurations have been developed and trained using the Levenberg Marquardt Back Propagation Algorithm in the Matlab routines. Networks were optimized using the enumeration technique, and, finally, the best network is used to predict the SSC values for the year 2011. The values thus obtained through the ANN model are compared with the observed values of SSC. The coefficient of determination (R2), for the optimal network was found to be 0.99. The study not only provides insight into ANN modeling in the Himalayan river scenario, but it also focuses on the importance of understanding a river basin and the factors that affect the SSC, before attempting to model it. Despite the temporal variations in the study area, it is possible to model and successfully predict the SSC values with very simplistic ANN models.     

Turbulence and suspended sediment processes in the Garonne River tidal bore in November 2016

A tidal bore is a water discontinuity at the leading edge of a ood tide wave in estuaries with a large tidal range and funneling topography. New measurements were done in the Garonne River tidal bore on 14 15 November 2016, at a site previously investigated between 2010 and 2015. The data focused on long, continuous, high-frequency records of instantaneous velocity and suspended sediment con- centration (SSC) estimate for several hours during the late ebb, tidal bore passage and ood tide. The bore passage drastically modi ed the ow eld, with very intense turbulent and sediment mixing. This was evidenced with large and rapid uctuations of both velocity and Reynolds stress, as well as large SSCs during the ood tide. Granulometry data indicated larger grain sizes of suspended sediment in water samples compared to sediment bed material, with a broader distribution, shortly after the tidal bore. The tidal bore induced a sudden suspended sediment ux reversal and a large increase in suspended sedi- ment ux magnitude. The time-variations of turbulent velocity and suspended sediment properties indicated large uctuations throughout the entire data set. The ratio of integral time scales of SSC to velocity in the x-direction was on average TE,SSC/TE,x 0.16 during the late ebb tide, compared to TE,SSC/ TE,x 0.09 during the late ood tide. The results imply different time scales between turbulent velocities and suspended sediment concentrations.     

Model Simulations of the Transport of Odra Flood Water through the Szczecin Lagoon into the Pomeranian Bight in July/August 1997

The Odra river flood of July through August 1997 transported a large additional volume of water into the Szczecin Lagoon area for a period of about one month. The dispersion of this water in the Szczecin Lagoon and Pomeranian Bight was simulated using the operational hydrodynamic model of the North Sea and Baltic Sea operated by the Federal Maritime and Hydrographic Agency of Germany (BSH). The model system receives as input meteorological forecast fields from the EUROPA model of the German Weather Service. As a result of the model simulation, the temporal development of the river plume can be described as follows: First the eastern part of Szczecin Lagoon, the Zalew Wielki, filled with flood water displacing θnormalρ Odra river water from that area. After about a week, Odra river flood water started to flow into the Pomeranian Bight. Its dispersion within Szczecin Lagoon was by no means uniform. The Kleines Haff, the western part of the Lagoon, was not much affected at first. When large labelled water masses had already left the Zalew Wielki area through the Swina river, at most only about half the water volume in Kleines Haff had been replaced by Odra flood water. In the Pomeranian Bight, the concentration was higher at the coast of Usedom – at least initially – than at the coast of Wolin. After 30 August 1997, northwesterly winds caused undiluted Baltic water to flow from the northern to the southern part of the Pomeranian Bight, pushing the water body marked, or distinguished, by Odra water eastward along the coast of Wolin. At the same time, outflow began from Kleines Haff through the Peenestrom into the Greifswalder Bodden. Due to light winds, and hence limited vertical mixing in summer, the proportion of freshwater in Baltic surface water reached about 50% in the southern Pomeranian Bight. Near Rügen, it fell below 10%. Within 2 months of stronger wind caused major shifts of the water bodies concerned. The scale considerations and model simulations discussed in this paper allowed qualitative estimates to be made in the course of the flood event, which were later confirmed by measurements, presented at a HELCOM (Helsinki Commission, Baltic Marine Environment Protection Commission) Scientific Workshop in January 1998.     

Total Organic Carbon (TOC) as a Sum Parameter of Water Pollution in Selected Polish Rivers (Vistula,Odra, and Warta)

This paper reports on total organic carbon (TOC) and its fractions dissolved organic carbon (DOC) and particulate organic carbon (POC) studied in different Polish rivers. The samples investigated came from the Vistula, Odra, and Warta rivers, and were compared with similar data on river waters available in the literature. The DOC concentrations ranged from 10.0 to 14.2 mg/L and did not vary during the vegetative season. The POC values considerably increased from May through September and reached a maximum in summer. Results for the years 1991τ1996 evidenced a significant increase in the POC value for the Polish rivers from 10.8 to 24.5 mg/L, in comparison with analogous values for West European rivers and North American ones. The enhanced values of TOC and POC were interpreted as being due to anthropogenic pollution.     

Changes in sediment transport in the Kuye River in the Loess Plateau in China

In this paper, the changes in sediment transport over 51 years from 1955 to 2006 in the Kuye River in the Loess Plateau in China are assessed. Key factors affecting sediment yield and sediment transport, such as precipitation depth, discharge, and human activities are studied. To investigate the changes in sediment yield in this watershed, a trend analysis on sediment concentration, precipitation depth, and discharge is conducted. Precipitation depths at 2 Climate Stations （CSs）, as well as discharge and sediment transport at 3 Gauging Stations （GSs） are used to assess the features of sediment transport in the Kuye River. The rtmoff modulus （defined as the annual average discharge per unit area, L/（s·km^2）） and the sediment transport modulus （defined as the annual suspended sediment transport per unit area, t/（yr km^2）） are introduced in this study to assess the changes in runoff and sediment yield for this watershed. The results show that the highest average monthly discharge during the study period in the Kuye River is 66.23 m^3/s in August with an average monthly sediment concentration of 88.9 kg/m^3. However, the highest average monthly sediment concentration during the study period in the Kuye River is 125.34 kg/m^3 and occurs in July, which has an average discharge of 42.6 m^3/s that is much less than the average monthly discharge in August. It is found that both the runoff modulus and sediment transport modulus at Wenjiachuan GS on the Kuye River has a clear downward trend. During the summer season from July to August, the sediment transport modulus at Wenjiachuan GS is much higher than those at Toudaoguai and Longmen GSs on the Yellow River. The easily erodible loess in the Kuye River watershed and the sparse vegetation are responsible for the extremely high sediment yield from the Kuye River watershed. The analyses of the grain size distribution of suspended load in the Kuye River are presented. The average monthly median grain size of suspended load in the Kuye River is largest in February and then decreases until June. In July, the average monthly median grain size of suspended load approaches another peak and decreases until September. Then, the median grain size of suspended load starts to increase until February of the following year. However, the average monthly median grain size of suspended load in the Yellow River at Toudaoguai and Longmen GSs is the smallest between early summer and late fall The median grain size in the Yellow River starts to increase in November and approaches the largest size in January.     

Recovery and concentration of suspended solids in the upper rhone river by continuous flow centrifugation

Six stations along the Rhône River from the Rhône Glacier to Lake Geneva were sampled by continuous flow centrifuge for recovery of suspended sediment. The samples were taken four times in the year in both 1982 and 1983. In addition, the mouth of the river was sampled in a like manner every two weeks during 1982 until August 1983. Concentration of sediment and composition did not vary as a function of depth or location across the river. Concentrations varied in time and as a function of flow and samples showed both increasing concentration in suspension and an increase in the proportion of finer particles moving downstream from source to mouth. Only slight variations in texture could be observed down the river as a function of time and appeared to relate to freezing and melting of the Rhône and other headwater glaciers as the primary sediment source. Little variation was observed annually in the texture and composition of the sediment at the river mouth despite large changes in concentration between the high flow summer and low flow winter discharges. These findings are consistent with a well-mixed system in which the suspended sediments are directly related to the primary supply of material from the glaciers.     

Seasonal and spatial variation in suspended matter,organic carbon,nitrogen, and nutrient concentrations of the Senegal River in West Africa

The Senegal River is of intermediate size accommodating at present about 3.5 million inhabitants in its catchment. Its upstream tributaries flow through different climatic zones from the wet tropics in the source area in Guinea to the dry Sahel region at the border between Senegal and Mauritania. Total suspended matter, particulate and dissolved organic carbon and nitrogen as well as nutrient concentrations were determined during the dry and wet seasons at 19 locations from the up- to downstream river basin. The aims of the study were to evaluate the degree of human interference, to determine the dissolved and particulate river discharges into the coastal sea and to supply data to validate model results. Statistical analyses showed that samples from the wet and dry season are significantly different in composition and that the upstream tributaries differ mainly in their silicate and suspended matter contents. Nutrient concentrations are relatively low in the river basin, indicating low human impact. Increasing nitrate concentrations, however, show the growing agriculture in the irrigated downstream areas. Particulate organic matter is dominated by C4 plants during the wet season and by aquatic plankton during the dry season. The total suspended matter (TSM) discharge at the main gauging station Bakel was about 1.93 Tg yr⁻¹ which is in the range of the only available literature data from the 1980s. The calculated annual discharges of particulate organic carbon (POC), dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) are 55.8 Gg yr⁻¹, 54.1 Gg yr⁻¹, and 5.3 Gg yr⁻¹, respectively. These first estimates from the Senegal River need to be verified by further studies.     

Sediment dynamics and temporal variation of runoff in the Yom River,Thailand

The Yom River is one of the four major sediment sources to the Chao Phraya River in Thailand. Human activities and changes in climate over the past six decades may have affected the discharge and sediment load to some extent. In the current study, the river discharge and sediment characteristics in the mainstream of the Yom River were investigated using the field observation data from 2011 to 2013 and the historical river flow and sediment data from 1954 to 2014 at six hydrological stations operated by the Royal Irrigation Department of Thailand (RID). The non-parametric Mann-Kendall test and double mass curve were used to analyze the sediment dynamics and temporal changes in the discharge of the Yom River. The results revealed that the sediment was mainly transported in suspension, and the bed-to-suspended sediment loads ratio varied between 0 and 0.05. The daily suspended sediment load (SSL) in the upper and middle basins had a strong correlation with the daily discharge and could be represented by power equations with coefficients of determination higher than 0.8. The daily suspended sediment load in the lower basin did not directly depend on the corresponding discharge because of the reduction in river slope and water diversion by irrigation projects. It also appeared that the river discharges and sediment loads were mainly influenced by climate variation (floods and droughts). Moreover, the average sediment transport of the upper, middle, and lower reaches were 0.57, 0.71, and 0.35 million t/y, respectively. The sediment load in the lower basin decreased more than 50% as a result of changes in the river gradient (from mountainous to floodplain areas). The results from sediment analysis also indicated that the construction of the Mae Yom Barrage, the longest diversion dam in Thailand, and land-use changes did not significantly affect the sediment load along the Yom River.     

Gravel excavation and geomorphic evolution of the mining affected river in the upstream reach of the Yangtze River,China

As economic development upstream in the Yangtze River basin has progressed in recent decades,the demand for sediment has rapidly increased and contributed to an expansion in sediment excavation that may affect the river’s stability and navigation safety.In the current study,the distribution of gravel mining in the upstream reach of the Yangtze River was investigated using field measurements obtained from2008 to 2017.An experimental investigation was then done to analyze the bed load behavior in ...     

Combined Effects of Molecular Size and Electroendosmotic Flow on the Capillary Electrophoretic Behaviour of Humic Substances

The electroendosmotic flow (EOF), generated by the migration of solvated ions near the charged capillary surface, is an important factor in determining the capillary electrophoretic behaviour of humic substances (HS). We investigated the electrophoretic mobilities of HS fractions of reduced molecular-weight polydispersity extracted from peat and from a spodosol either in the presence or after suppression of the EOF. When the EOF was not suppressed, HS migrated to the cathode in spite of their negative charge. Fractionation of HS according to molecular size was achieved in polyacrylamide-coated capillaries filled with 0.05 M tris-phosphate buffer. In uncoated capillaries filled with the same buffer, all fractions had very close mobilities. Addition of polyethylene glycol MW 4000 at concentrations above its entanglement threshold caused the migration times of larger molecules to increase more than those of smaller molecules. The separation was a linear function of molecular size up to 75000 g mol^–1 for peat HS and to 50000 g mol^–1 for HS extracted from the spodosol.