Desortova B.,T. G. Masaryk Water Research Institute |
Puncochar P.,Section of Water Management
Limnologica | Year: 2011
The results are presented of an intensive study of phytoplankton assemblage carried out in the Berounka River above its confluence with the Vltava River (Czech Republic) in the period 2002-2007. The annual and interannual changes of phytoplankton development (based on high frequency of sampling) and their relation to hydrological conditions and concentrations of main nutrients are analysed. A marked decline of nutrient concentrations was observed during the period 1996-2007. The annual mean values of total P decreased from 0.43mgL-1 to 0.16mgL-1, those of N-NO3 from 4.6mgL-1 to 1.5mgL-1 and N-NH4 from 1.9mgL-1 to 0.04mgL-1. Despite this, the phytoplankton biomass remained at a high level. The seasonal mean values of chlorophyll-a ranged from 51.0μgL-1 to 116.8μgL-1 in the same time period. An obviously stronger relationship was found of the phytoplankton biomass and pattern of its development to the variation of flow rates than to the existing level of nutrient concentrations. A significantly decreasing relationship (R2=0.384, P<0.001) of chlorophyll-a to flow rates and a significantly increasing relationship (R2=0.359, P<0.001) of chlorophyll-a to water temperatures were found, based on monthly mean values for the seasonal period 2002-2007. The results obtained indicate a remarkable increase of phytoplankton biomass and its prolongated occurrence in watercourses, which can be expected due to the consequences of the predicted climate change (i.e. higher occurrence of summer droughts and low precipitation amounts accompanied by a substantial drop of flow rates, increase of air and water temperatures), as described in the respective scenarios for the territory of the Czech Republic. Simulations by the regional climate models HIRHAM and RCAO and emission scenario SRES indicated the increase of air temperature by 2.5-5°C, decrease of precipitation amount by 6-25% and decline of flows by 14-43% in the Berounka River for the scenario period 2071-2100. © 2010 Elsevier GmbH.
Stastny J.,Charles University |
Stastny J.,T. G. Masaryk Water Research Institute
Fottea | Year: 2010
The present work summarizes the current diversity, distribution and autecology of desmids found within the Czech Republic; the focus is on the occurrence and autecology of rare taxa. Data are based on the author's extensive sampling from 2003-2009, during work for both his master's degree, and currently, his Ph.D. dissertation. Over 1 400 samples were collected, from various types of wetland habitats ranging from eutrophic fishponds, diverse bogs and fens, to ephemeral pools and various aerophytic habitats. Altogether, 526 taxa of desmids (401 species) belonging to 27 genera were found, 80 of them newly described in the Czech Republic. In the present work, 169 rare or otherwise noteworthy taxa, belonging to the following genera: Mesotaenium (1), Netrium (1), Roya (2), Tortitaenia (1), Gonatozygon (2), Closterium (14), Haplotaenium (2), Pleurotaenium (3), Docidium (1), Actinotaenium (6), Euastrum (9), Micrasterias (7), Cosmarium (78), Xanthidium (7), Staurodesmus (4), Staurastrum (25), Cosmocladium (2), Sphaerozosma (2), Hyalotheca (1) and Desmidium (1) are depicted by line drawings and briefly discussed with regard to their ecology, taxonomy or distribution within the Czech Republic or Central Europe. In addition, SEM images are provided for 45 taxa, and, finally, a comprehensive table is included with indicative notations concerning all taxa found. © Czech Phycological Society.
Benakova A.,T. G. Masaryk Water Research Institute |
Wanner J.,Institute of Chemical Technology Prague
Environmental Technology (United Kingdom) | Year: 2013
The aim of this study was to verify fluorescence in situ hybridization for the detection of nitrifying bacteria in activated sludge and biofilms, and to determine the distribution of nitrifiers in selected wastewater treatment plants (WWTPs). Both Czech and foreign WWTPs with intensification of nitrification (for example, in situ bioaugmentation of nitrification or biofilms) and without intensification were studied. The two-dimensional and three-dimensional analyses of microscopic images were focused on quantifying the parameters and their differences with regard to the arrangement, capacity and sludge age of the WWTPs. This is the first time such a study has been performed in the Czech Republic. © 2013 Taylor & Francis.
Straka M.,Masaryk University |
Syrovatka V.,T. G. Masaryk Water Research Institute |
Helesic J.,Masaryk University
Hydrobiologia | Year: 2012
The aim of the present study was to estimate the extent to which macroinvertebrate assemblages in a headwater stream are determined by environmental conditions and temporal dynamics. Six mesohabitats defined by substratum were sampled monthly throughout one year, environmental conditions at each sampling point being precisely described. Environmental variables could be truncated into two main gradients related to (a) the availability of food and space resources (CPOM) and (b) hydraulic conditions. The response of the macroinvertebrate assemblage to the environmental gradients and temporal dynamics were analyzed using GAM and (p)RDA. Twice as high portion of variance in the faunal data was attributed to environmental gradients compared to temporal dynamics. Total abundance, as well as the abundance of almost all feeding groups, was dependent on the availability of food and space resources (CPOM), while their proportions were determined by the quality of food resources driven by hydraulic conditions. Temporal dynamics was of lower importance. Our results suggest the role of CPOM be crucial in woodland headwater streams, as it greatly enhances habitat quality, serving both as a food source to dominant shredders and a space source to most macroinvertebrates. © 2012 Springer Science+Business Media B.V.
Baker D.R.,University of Huddersfield |
Ocenaskova V.,T. G. Masaryk Water Research Institute |
Kvicalova M.,T. G. Masaryk Water Research Institute |
Kasprzyk-Hordern B.,University of Bath
Environment International | Year: 2012
This manuscript reports, for the first time, a monitoring study analysing wastewater and associated suspended particulate matter (SPM) to determine the concentration of drugs of abuse and metabolites in wastewater influent. The monitoring of SPM is crucial for target analytes because, depending on their physico-chemical properties, they may partition to particulates; thus, analysis of wastewater only will result in under-reporting of the concentration of target analytes in the sample. A daily one week monitoring study was carried out at a WWTP serving one of the largest cities in the Czech Republic; representing the first comprehensive application of the sewage epidemiology approach in the Czech Republic. In total, 60 analytes were targeted in the monitoring programme including stimulants, opioid and morphine derivatives, benzodiazepines, antidepressants, dissociative anaesthetics, drug precursors and their metabolites. Analysis of SPM determined that significant proportions of some compounds were present on the solids. For example, 21.0-49.8% of the total concentration of EDDP (2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine) in the sample was determined on SPM and 11.2-19.6% of methadone. The highest proportion on SPM was determined for fluoxetine in the range 68.1-79.6%, norfluoxetine 46.6-61.9% and amitriptyline 21.8-51.2%. In contrast, some compounds presented very little partitioning to SPM. Less than 5% was determined partitioned to SPM over the week period for analytes including cocaine, benzoylecgonine, cocaethylene, amphetamine, methamphetamine, MDMA (3,4-methylenedioxymethamphetamine), codeine, dihydrocodeine, tramadol, nortramadol, oxazepam and ephedrine. Determined concentrations in wastewater influent were subsequently utilised in the sewage epidemiology approach to estimate drug consumption, in the community from which the wastewater was derived. This back-calculation was updated for the first time to include the concentration of analytes present on SPM. The consumption of methamphetamine and MDMA was determined to be especially high in the studied community in relation to other European countries, while cocaine and methadone consumption was relatively low. This manuscript shows that in order to apply the sewage epidemiology approach, SPM analysis is required for some compounds; whereas for others the partitioning is small and one may regard this as negligible. © 2012 Elsevier Ltd.
Hanel M.,T. G. Masaryk Water Research Institute |
Hanel M.,Czech University of Life Sciences |
Hanel M.,Technical University of Liberec |
Maca P.,Czech University of Life Sciences
Hydrological Processes | Year: 2014
Rain event characteristics are assessed in a 10-year (1991-2000) record for 122 stations in the Czech Republic. Individual rain events are identified using the minimum interevent time (mit) concept. For each station, the optimal mit value is estimated by examining the distribution of interevent times. In addition, various mit values are considered to account for the effect of mit on rain event characteristics and their interrelationships. The interdependence between rain event characteristics and altitude, average rainfall depth, and geographic location are explored using simple linear models. Most rain event characteristics can be to some extent explained by average total rainfall or altitude, although models including the former significantly outperformed models using the latter. Significant correlation was found among several pairs of monthly mean characteristics often including event rain rate (with event duration, depth, maximum intensity, and fraction of intraevent rainless periods). Moreover, strong correlation was revealed between number of events, interevent time, event depth, and duration. In general, correlation decreases in absolute value with mit. Strong spatial correlation was found for the mean monthly interevent time and number of events. Spatial correlation was considerably smaller for other characteristics. In general, spatial dependence was smaller for larger mit values. © 2013 John Wiley & Sons, Ltd.
Hanel M.,Czech University of Life Sciences |
Hanel M.,T. G. Masaryk Water Research Institute |
Buishand T.A.,Royal Netherlands Meteorological Institute
Journal of Hydrology | Year: 2012
This paper presents an analysis of seasonal precipitation extremes in an ensemble of fourteen transient regional climate model (RCM) simulations for durations varying from 1 to 30. days. It is assumed that these precipitation maxima follow a generalized extreme value (GEV) distribution with time-varying parameters. In addition, spatial pooling of the maxima at various grid boxes is applied to reduce the uncertainty of the parameters of the GEV model. Relatively large positive biases in moderate quantiles of long-duration precipitation extremes have been found in autumn, winter and spring. The extreme quantiles are much better reproduced in these seasons. In summer, the ensemble mean bias in the quantiles is negative and decreases (in absolute value) with increasing duration. The ensemble mean changes in the quantiles are positive for all durations, return periods and seasons considered. Large quantiles of the distribution of summer precipitation extremes increase more than moderate quantiles and this increase is relatively large at short durations. The dependence of the changes on duration and return period is much weaker in the other seasons, in particular in winter and spring. Although the spread in the RCM ensemble is considerable, most of the RCM simulations agree on the sign of the changes. © 2011 Elsevier B.V.
Hrncir M.,Czech Technical University |
Sanda M.,Czech Technical University |
Kulasova A.,T. G. Masaryk Water Research Institute |
Cislerova M.,Czech Technical University
Hydrological Processes | Year: 2010
The study is focused on runoff formation processes at two scales: the scale of a small mountainous catchment at its outlet and the scale of an experimental plot located in a typical hillslope subregion. The heterogeneous soil profile of the catchments is formed by Cambisols developed on granite bedrocks. The surface runoff appears rarely, the subsurface flow forms a dominant part of the hydrograph. From the period 1998-2008, a set of 44 rainfall-runoff episodes was selected to analyse the rainfall-runoff relationship using multiple regression analysis. From a set of physical parameters, the initial soil water content came out as the statistically significant parameter that controls the runoff forming process at the catchment scale. The rainfall-runoff relationship at the experimental plot scale is more scattered. The dynamic thresholds of rainfall totals apparently control the ratio and the magnitude of stormflow at both scales. Up to the threshold value, the runoff strongly depends on the initial saturation conditions. Above the threshold value, the initial soil moisture conditions are less important. Copyright © 2010 John Wiley & Sons, Ltd.
Soldan P.,T. G. Masaryk Water Research Institute
Environmental Monitoring and Assessment | Year: 2011
Water ecosystems are threatened by accidental spills of pollution. Rapidity and trueness of information gathering the biological impact of accidental pollution is crucial for the efficiency of the minimisation of possible deterioration of ecosystems and for success in detecting the source of pollution. Due to the randomised occurrence of accidental spills the only way to quickly detect hazardous situations is to perform continuous monitoring of surface water quality. The current situation in the field of early warning in the International Odra (Oder) River basin is not satisfactory. The actual number of monitoring stations and list of routinely continuously monitored parameters are not able to meet the needs of sensitive and rapid detection of biological impact of accidental pollution spills. An effort to change this unfavourable situation was the reason for the offer survey, selection and a model operation of a commercially produced biological monitoring device. This apparatus was located on the border-line profile on the territory of the Czech Republic and represented the first and only one tool of continual biological monitoring of surface water quality in the International Odra (Oder) River Basin. The selected apparatus was the Daphnia Toximeter produced by the firm bbe Moldaenke (Kiel, Germany). This device exploited for rapid detection of changes of biological quality of surface water evaluation of behavioural response of monitoring organisms-daphnids. Five years of model operation proved its suitability for early warning purposes. The apparatus was reliable in function and sensitive enough to detect the deterioration of the biological quality of the river water. The given examples document its applicability not only for detection of accidental spills but also of illegal emissions of pollution, which are very often toxic. © 2010 Springer Science+Business Media B.V.
Soldan P.,T. G. Masaryk Water Research Institute |
Badurova J.,T. G. Masaryk Water Research Institute
Environmental Monitoring and Assessment | Year: 2013
The article describes a method for screening for the risk of chronic surface water pollution which was developed at the T. G. Masaryk Water Research Institute. The approach, which is based on exotoxicological analyses, can be classed as a rapid method of assessment. The degree of risk of chronic effects surface water pollution is determined from an evaluation of two major parameters - toxicity and genotoxicity. As the method utilizes relative simple procedures for sample collection, pretreatment of the sample, chemical analyses, bioassays and results assessment, this approach is suitable for widespread practical use. Extensive utilization of this approach for assessing river basins in the Czech Republic has proved its suitability for a more sophisticated detection of the biological impact of surface water pollution. This is documented in the article where the method is used in a study of the Bílina River, and in the overview of the results of the risk assessment of chronic effects of surface water pollution in selected sections of three international river basins in the Czech Republic. © 2012 Springer Science+Business Media B.V.