Sava River Basin Research Articles

A complex investigation of the extent of pollution in sediments of the Sava River. Part 1: Selected elements

The Sava River is the biggest tributary to the Danube River. As a part of the 6th FW EU project, Sava River Basin: Sustainable Use, Management and Protection of Resources (SARIB), ecological status of sediments was investigated. In order to assess the geographical distribution in sediment contamination of the Sava River, inorganic and persistent organic pollutants were analyzed in sediments at 20 selected sampling sites along the Sava River from its spring to its outfall into the Danube River. For comparability of data to other river basins the sediment fraction below 63 microm was studied. Due to complexity of the work performed, the results are published separately ("Part I: Selected elements" and "Part II: Persistent organic pollutants"). In the present study, the extent of pollution was estimated by determination of the total element concentrations and by the identification of the most hazardous highly mobile element fractions and anthropogenic inputs of elements to sediments. To assess the mobile metal fraction extraction in 0.11 mol L(-1), acetic acid was performed (first step of the Community Bureau of Reference extraction procedure), while anthropogenic inputs of elements were estimated on the basis of normalization to aluminum (Al) concentration. According to the Water Framework Directive, the following elements were investigated in sediments: cadmium (Cd), lead (Pb), nickel (Ni), and mercury (Hg). Furthermore, copper (Cu), zinc (Zn), chromium (Cr), arsenic (As), and phosphorous (P) were determined. The analyses of sediments demonstrated slightly elevated values for Hg, Cr, and Ni in industrially exposed sites (concentrations up to 0.6, 380, and 210 mg kg(-1), respectively). However, the latter two elements exist in sparingly soluble forms and therefore do not represent an environmental burden. P concentrations were found in elevated concentrations at agricultural areas and big cities (up to 1,000 mg kg(-1)).

A complex investigation of the extent of pollution in sediments of the Sava River: part 2: persistent organic pollutants

Sediment pollution of the biggest Danube tributary, the Sava River, was investigated within the sixth framework European Union project "Sava River Basin: Sustainable Use, Management and Protection of Resources" (SARIB). The extent of pollution was estimated by determining the amount of inorganic and persistent organic pollutants in sediment samples at 20 selected sampling sites along the Sava River. For the purpose of clarity, the findings are presented and published separately (part I: selected elements and part II: persistent organic pollutants). This study presents an investigation into the presence of organic pollutants in the Sava River sediment. According to the Water Framework Directive, the following persistent organic pollutants were investigated: polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), selected chlorinated pesticides and organotin compounds. The results reveal that PAHs were present in moderate concentrations (sum of 16 PAHs: up to 4,000 ng g(-1)) and their concentrations increased downstream. Concentrations of PCB were low (sum of seven indicator PCBs: below 4 ng g(-1)) and among the pesticides analyzed only p,p-dichlorodiphenyltrichloroethane was found in moderate concentrations at two sampling sites in Croatia (up to 3 ng g(-1)) and hexachlorobenzene was found in a high concentration in the city of Belgrade (91 ng g(-1)), although the use of these persistent pesticides has been banned for decades. Repeated sampling at the same location revealed point pollution near Belgrade. Among the organic pollutants surveyed, organotin compounds were not detected. Overall results reveal the presence of persistent organic pollutants in 20 of the Sava River sediments tested that is, in general, comparable or lower than the levels in the Danube River and other moderately polluted European rivers.

Automatic calibration of the Watbal model

Slovenia is very rich with water. Sava river basin is the biggest one in Slovenia and it covers 53% of Slovenian area, which means approximately 10760 km2. Because of its importance in year 2006 water balance analysis of Sava river basin under the name SARIB was done [10]. In the SARIB project model Watbal was used [6]. We had a lot of problems with calibrating it via standard way using Excel's Goal Seek function in combination with method of trials and errors. Because of that we developed a new algorithm PETTON in Matlab for automatic, fast and reliable calibration of model Watbal. The new calibration results were better and model Watbal was more successful in prediction. In this article we will briefly present the main ideas of optimisation and calibration, model Watbal and algorithm PETTON. At the end we will present comparison between SARIB results and new results, which we get by using PETTON.

The implementation of the HBV model on the Sava River Basin

The Swedish HBV model was used for modelling the Sava River discharge and modelling of snow cover over the Sava river watershed in Slovenia. The Sava River is the largest river in Slovenia and tributary of the Danube River, contributing to its largest runoff. It covers more than half of the territory of Slovenia, namely 10700 km2. The watershed is heterogeneous, mountainous in the upper parts and plain in the middle reach. There are also some karstic regions. The floods are caused by heavy rainfall in headwater mountain areas, especially in autumn. Some tributary flows can rise more than a hundred times in such events. For the purpose of flood forecasting the HBV model was set up for the whole watershed using the time step of 24 hours to calibrate the set of model parameters, which then used for recalibration of the model with time step of 1 hour. The watershed was divided to 26 subcatchments. Model input data are precipitation, potential evapotranspiration, and in case of climates with temperatures below zero, temperature data. Measured discharges are needed to calibrate, verify and up-date the model. Satisfactory calibration of the model was achieved, although the topography has strong influence on the meteorological happening in the catchement, especially in the upper stream of the Sava river, and small number of available raingauges.

Assessing the usefulness of the water poverty index by applying it to a special case: Can one be water poor with high levels of access?

Using indices and indicators in assessment of progress of a developing country has two sides. Such indicators offer an easy-to-understand shorthand/synopsis of issues vital for a country’s development. The other side of the coin, however, is that this synopsis may be distorted due to incorrect data or inapplicability of an index or an indicator to a specific case. This paper assesses the applicability of Water Poverty Index for the countries riparian to the Sava sub-basin, a tributary to the Danube river basin and presents the results of its application. At the same time, the paper discusses the concept of water poverty and the appropriateness of its use in the case of Sava River Basin countries by differentiating the economic poverty in some of those countries from sufficient access to and use of water resources in all of them.

Diffuse sources of nitrogen compounds in the Sava river basin, Slovenia

The enrichment of natural waters by nutrients from different sources has been associated with eutrophication in many Europe river basins. Materials accounting is a multidisciplinary approach to identify precisely the sources of pollution and to assess the most efficient preventive means to avoid these problems. A methodology for the evaluation of nitrogen balance was developed and applied for a case study on the Sava river basin, Slovenia. Total emission of nitrogen into the Sava river basin was estimated to be 18.6 kilotons per year. The results indicate that at present level of treatment and today’s agricultural practice, the main sources of nitrogen originate from process wastewater management (62% from point sources and 4% from diffuse sources when compared to the total emission) and agriculture (3% from point sources and 28% from diffuse sources again compared to total emission). Atmospheric deposition contributes relatively in a small percentage of the total loading (3%). The results of the study showed that besides the reduction of point sources by implementing nutrient removal technologies, the management of agricultural pollution should become a major task with the aim to reduce the total load of nitrogen to river system.

International legal regulation of protection and sustainable use of water courses

The article deals with international legal regulation of protection and sustainable use of watercourses with special reference to the Sava River Basin. This regulation is considerably developed on universal, regional and sub regional international levels by a substantial number of declaratory treaty and other acts dealing with the subject. In case of the river Sava the basic frame for regulation is on the European level: the documents concerning the Danube River as a whole, and particularly the Framework Agreement on the Sava River Basin. The author stresses that adoption and ratification of this document is probably one of the biggest step forward in co-operation between Slovenia, Croatia, B&H, and Serbia and Montenegro.

New discovery of the Ukrainian brook lamprey in Croatia

The Ukrainian brook lamprey Eudontomyzon mariae was collected in two streams belonging to the Sava river basin in Croatia. The great variation in morphological characters of this species is emphasized and its description is augmented. Clinal variation in the trunk myomeres, total length and the oral disc dentition is detected.

The Relationship Between the Sava River Basin Annual Precipitation, its Discharge and the Large-Scale Atmospheric Circulation

The Sava river annual precipitation field and the discharge anomalies in the Sava river catchment are compared to each other and to mean sea-level pressure anomalies over Europe. In addition to a correlation analysis a clustering technique is used for the time series from 1901–1990. Discharge data are available only for the period 1931–1990. As expected, a high correlation exists between the Sava river discharge and precipitation, but also, remarkable correlation is found between air pressure anomalies and Sava river precipitation. Grouping the years into four classes, the correlation is shown to be especially high for extreme events. A possible application of these results might be for the downscaling of long-lead climate anomaly forecasts.

The performance of surface and subsurface drainage on heavy clay soils in Yugoslavia.

The soils of the Sava River basin (Yugoslavia) have a permeable topsoil of about 0.3 m depth, which overlies an impermeable subsoil. During rainfall, horizontal flow through the topsoil occurs. Appropriate formulae for steady and non-steady flow have been derived, which, together with field observations on field accessibility, have permitted the determination of drainage requirements. In selecting the best drainage system the projected mechanization of agriculture in the area has been considered. Partly for this reason, partly because it provides better drainage during reclamation and in the first year of cropping, and partly for long-term economic reasons (initial costs are higher), subsurface drainage (1.0-1.2 m depth and 15 m drain distance) is preferred to surface drainage. Factors determining peak discharges of field drains are discussed. (Abstract retrieved from CAB Abstracts by CABI’s permission)