VTEI / List of articles

List of articles from – 4/2023

The influence of wastewater on microbial contamination of the Vltava below Prague

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In terms of public health protection, the most important indicator in surface water monitoring is microbial fecal contamination. Despite the introduc-tion of the best available technologies, their biggest source is treated and untreated municipal wastewater. Around 90 % of the Czech population use their local sewerage system, which is linked to a WWTP, treated, and discharged into recipient waters. Monitoring of microbial contamination of the Vltava below Prague CWWTP showed a level of fecal pollution in the 10 km section below the wastewater inflow in periods with different flow rates. Smaller tributaries of the Vltava, which bring treated wastewater from local WWTPs to the Vltava, were monitored as additional sources. From April 2022 to March 2023, the amount of Escherichia coli, enterococci, thermotolerant coliform bacteria, and Clostridium perfringens were monitored at ten sampling sites. The monitoring results showed relatively significant microbial pollution of the Vltava from Prague CWWTP dis-charge and, at the same time, the river’s substantial self-cleaning ability in the following section. This creates good potential for the river’s future utilization in the monitored area, with the exception of the section directly affected by the inflow of treated wastewater from Prague CWWTP. This study could be used to raise public awareness in order to minimize the health risk caused by the river’s inappropriate utilization (possible presence of pathogenic microorganisms, including carriers of antimicrobial resistance).

Application for the parametrization and automatic running of the HEC-HMS rainfall-runoff model

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This article presents an application developed in the Czech Hydrometeorological Institute (CHMI) to support hydrologic modelling using the HEC-HMS model as the primary used rainfall-runoff model. The application enables group editing of selected parameters of the model schematiza-tion, automatic running of simulations, display of selected simulation results, and communication of the HEC-HMS
model with GIS and other selected models, e.g., HEC-RAS or MIKE 11. The application is designed to use only freeware and open source libraries and is capable of operating under both Windows OS and UNIX/Linux OS. This article briefly describes the current state of the application devel-opment and its functionality, even for readers without major IT background. Further development is outlined in the last part of the article. Further development of the application is aimed at higher support for hydraulic modelling at the level of communication between the HEC-HMS and HEC-RAS models, as well as at the level of automatic parameterization and launching of the HEC-RAS model and its communication with other tools, e.g. hydraulic model MIKE 11 or GIS post-processing of the results.

Atmospheric deposition as a possible source of surface water pollution (Results of the project, part 2. – polycyclic aromatic hydrocarbons)

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From October 2020 to September 2021, in two forest micro-catchments in the Czech Republic, the quality of wet atmospheric deposition (bulk and throughfall) was monitored simultaneously with the surface water quality in the local watercourse, humus, and the moss species Pleurozium schreberi. An evaluation is presented of the 15 polycyclic aromatic hydrocarbons (PAHs) burden of the above-mentioned matrices. The first site was chosen in the Beskid Mountains in the Moravian-Silesian region, in the cadastre of the village of Bystřice in the upper basin of the Suchý stream (altitude 590 to 835 m a.s.l.). This area is affected by industrial activities. The second reference site was chosen in the Bohemian-Moravian Highlands near Košetice observatory (altitude 520 m a.s.l.).

Development of pond locations in the Polabí lowland since the mid-19th century – part 2 – Poděbrady region

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This article presents the results of research on landscape changes in the Poděbrady region as part of the Polabí lowland, where there have been significant changes in the location of ponds. The area of all types of ponds (according to stability) makes up 3.17 % of the Poděbrady region. Ac-cording to their occurrence in the area in 1836/1852–2022, the ponds (or their parts) were divided into disappeared, continuous, and new. Disap-peared ponds have the largest representation – about 60 % of the total pond area according to stability. They are followed by continuous ponds, with the minimum area represented by new ponds. The historical or (more precisely) disappeared ponds were more robust than the present ones, i.e., they had a larger average size. Analyses show that almost three-quarters of the disappeared ponds have been replaced by arable land.

Wastewater based epidemiology, determination of selected illicit drugs and Covid-19 pandemic

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The World Health Organization (WHO) declared an outbreak of a global health emergency on 30th January 2020 and a pandemic caused by Covid-19 in March of the same year. In our paper, we tried to find out if and how this situation affected drug consumption from the perspective of wastewater analysis. We compared the results of weekly sampling events from 2019, 2020, 2021 and 2022, which took place at approximately the same period of the year, but in 2020, 2021, and 2022 were affected by the state of emergency and other pandemic-related measures. We monitored the concentration of selected drugs – THC, methamphetamine, MDMA, cocaine, and some of their metabolites (amphetamine and benzoylecgonine) in wastewater samples taken at the inflow to wastewater treatment plants. According to our measurements, virtually all monitored drugs experienced changes in their consumption.

Fundamental revision of the Urban Waste Water Treatment Directive provokes conflicting reactions from European Union member states

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Council Directive 91/271/EEC of 21st May 1991, the Urban Waste Water Treatment Directive (UWWTD), entered into force 32 years ago, which is a respectable age for a legal regulation. Since then, through the consistent implementation of its requirements, good results in water protection have been achieved in practice. Between 1990 and 2014, there was a reduction in the amount of pollutants in treated and discharged urban waste water for organic pollution expressed as BOD5 by 61 %, for total nitrogen by 32 %, and for total phosphorus by 44 %. The extensive support pro-vided to cities and municipalities from EU financial instruments as well as from national sources and the relatively strict application of sanctions have led, according to data published by the European Commission (EC), to the fact that currently 98 % of waste water in the EU is effectively collected and removed of and 92 % properly treated. Until now, the Directive’s requirements have primarily focused on centralized systems for the collection, removal, and treatment of waste water in agglomerations producing loads at the level of 2,000 population equivalent (PE) and more.

Graphical use of AI

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In the June VTEI issue, we got familiar with the AI tool ChatGPT in the form of an “interview”. We continue with the topic of artificial intelligence and this time we present experiences with a more “visual” tool. Our intention was to create different visualizations of the situation using text input, the so-called “prompt”, or from a master photo, for example a watercourse restoration or the idea of building a water tower in the country-side. But before we get to the visualizations themselves, let us say a few words about this topic.

Native versus invasive crayfish in the Czech Republic

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A decrease in species diversity is a negative consequence of many human activities. The number of native animal and plant species is decreas-ing, their populations are shrinking or completely disappearing, the number of endangered species is increasing, and non-native species are spreading. Global problems are perhaps most evident in the example of freshwater ecosystems.
Invasions of non-native species, associated with high cultural-sociological and economic losses, are currently considered one of the most sig-nificant factors in the decline of species diversity. For these reasons, the issue of non-native species is receiving considerable attention world-wide.
There are currently six species of crayfish living in the wild in the Czech Republic, of which only two are native: noble crayfish (Astacus asta-cus) and stone crayfish (Austropotamobius torrentium). Narrow-clawed crayfish (Astacus leptodactylus) is a European species but not native to the Czech Republic. Other species – signal crayfish (Pacifastacus leniusculus), spiny-cheek crayfish (Orconectes limosus), and marbled crayfish (Procambarus fallax) come from North America and are invasive species [1, 3].