Hydraulics, hydrology and hydrogeology

Protected areas of natural water accumulation – their meaning in the current system of water environment protection

This article discusses the development, management, and use of the landscape in the form of a declaration of a Protected Area of Natural Water Accumulation (CHOPAV). It examines the importance of this method of protection in the water protection system under the requirements of the Water Framework Directive and other European directives which have been incorporated into the legislation of the Czech Republic. It looks at the possibilities of using this tool in water management to deal with problems caused by climate change. Based on the research and analysis carried out, the article recommends modifications to the CHOPAV regime and area modifications, as well as expansion to other sites.

Development of land use and impact on water resources of hydrogeological unit 4232 Ústecká syncline in the Svitava river basin

The research area of hydrogeological unit 4232 Ústecká Syncline in the Svitava river basin (Ústecká synklinála v povodí Svitavy) is an important area of underground drinking water sources. These resources are of the highest quality and among the most abundant resources in the entire Czech Republic. The development of land use is closely connected with the development of settlements and industry (textile) in the research area, which in their importance far exceeded the borders of the region. Gradual development created pressure on natural resources, especially water; the demands on the quantity of service and drinking water increased, while the quality of water was affected by industrial and agricultural pollution. Despite the observed decrease in population in the last twenty to thirty years, we can see the expansion of settlements, mainly due to new construction on agri-cultural land, which is slightly compensated by the expansion of permanent grasslands and forests. With regard to current and future climate change, this increase, together with a slight increase in water bodies, can be considered as a positive phenomenon.

Use of effect-based methods to assess surface water status

This article deals with the use of effect-based methods for the qualitative assessment of the state of surface waters in the context of Directive 2000/60/EC establishing the framework for Community activity in the field of water policy and the upcoming amendment to Directive 2008/105/EC on environmental quality standards. The implemented monitoring of priority substances and specific pollutants is not able to capture all sources of pollution that negatively affect surface water quality. Likewise, current practice does not allow a comprehensive assessment of mixtures, including emergent pollutants, metabolites, and transformation products of substances on water quality. Effect-based methods are a suitable tool for ecotoxi-cological evaluation of pollution, which considers all substances contained in the sample and possible effects of mixtures (synergistic effects). They thus provide important additional information for the results of the assessment of the state of surface water bodies.

Interview with prof. Ing. Pavel Pech, CSc., professor at the Czech University of Life Sciences Prague

the future be over water rather than oil and land? Why is he more afraid of genes than climate change? And is it better to build dams and large water reservoirs, or establish ponds, wetlands, and pools? What is his opinion on artificial intelligence? These are just some of the topics that I discussed with prof. Ing. Pavel Pech, CSc., long-time head of the Department of Water Resources and Environmental Modeling at the Czech University of Life Sciences (CULS). “I’m from Hnojárna,”* he says about himself with a smile, and it does not sound pejorative at all – after all, he is the founder of the Faculty of Environmental Sciences at CULS in Prague.

Looking back at the National Dialogue on Water 2023

After a four-year break caused by the covid pandemic, the National Dialogue on Water took place on 25–26th October 2023, this time in the Skalský Dvůr hotel in Vysočina. The event was organized by the T. G. Masaryk Water Research Institute, p. r. i. (hereinafter TGM WRI) in coop-eration with the Czech Scientific and Technological Water Management Company (Česká vědeckotechnická vodohospodářská společnost, z. s.) The main theme of the event was a comprehensive approach to the protection of drinking water sources. This topic was addressed by a large number of experts from the field of water management (118 participants), whether it was representatives of the Ministry of the Environment (MoE), Ministry of Agriculture (MoA), Ministry of Health, state-owned River Basin State Enterprises, the Czech Hydrometeorological Institute (CHMI), water authorities, operators of water supply and sewerage systems (VaK), mayors, private companies, hydrogeologists, and others.

Kozmice bird meadows and their importance for nature and landscape

Alluvial wetlands and alluvial meadows (often referred to as “wet” in the literature) are one of the types of habitats that, with the gradual develop-ment of the cultural landscape, suffered the greatest transformation and often complete disappearance; in the Czech Republic, the most significant transformation by the transfer to field crops together with land improvement peaked roughly in the 1970s. Discussions about the importance of wetlands have, however, been revived in different periods; the factors that trigger these discussions are mainly floods and drought, which is clearly indicated by the drought that started in 2015. In their name, alluvial wetlands and meadows indicate that they are situated in a river landscape and are in periodic or constant contact with the surface water of larger rivers and groundwater, including the hyporeal. It is therefore obvious that these landscape elements are at least locally important for the cycle of water and chemical substances in the river landscape.

Direct monitoring of water vapor from the free water level of the Vavřinecký pond and its influence on the hydrological balance

With increased average air temperature, there is an increase in water vapour from a water surface. Between 2020 and 2022, evaporation from the water surface was observed with a floating evaporimeter at Vavřinecký pond in the Central Bohemian region. A floating evaporimeter monitors evaporation from the water surface along with basic meteorological quantities directly on the surface of the water reservoir, so its results should be more accurate than calculations based on data from nearby meteorological stations. The results show that in all three years evaporation exceeded precipitation by more than 100 mm between April and September. However, the issue of the influence of small water reservoirs on the hydrological balance is a very complex topic, where the assessment of negative and positive effects is not always black and white and requires detailed investiga-tion.

Drought warning system and local threshold limits

Droughts and floods are extreme hydrological phenomena that are currently increasing in frequency due to the growing impact of climate change, and can have significant effects on our lives. Within the “PERUN” research project, an assessment of drought conditions and their development in the Czech Republic is being developed, along with the innovation of the warning system by the Czech Hydrometeorological Institute (CHMI). Drought is a natural phenomenon characterized by a gradual onset, long duration, and low dynamics, which requires a specific approach. The amendment to the Water Act introduces the obligation of regular reporting on drought and the establishment of a predictive service to be conducted by CHMI. Tools are being developed for long-term prediction of water resource conditions and a methodology for drought and water scarcity management plans. These plans aim to ensure water supply, protect the environment, and minimize the economic impacts. The decision-making body for issuing measures based on the drought plans is the Drought Commission, which operates at the regional level. The warning information is available on the HAMR web portal, which also displays local threshold limits for individual water resources.

Protected areas for surface water accumulation from a hydrogeologist’s the point of view – the effect of possible realization of surface water accumulation on hydrogeological conditions

Suitable areas for the accumulation of surface water have been defined in the Czech Republic, potentially serving mainly for the supply of potable water and for mitigating the adverse effects of floods and drought. The sites are listed in the General Scheme on the Accumulation of Surface Water, which was obtained by the Ministries of Agriculture and the Environment following the previous long-term territorial protection of prospective water reservoirs. Before any decision to build these reservoirs, it is necessary to assess the project from various points of view. This article presents an evaluation of selected sites from a hydrogeological point of view. Among other things, it deals with the analysis of the location of potential res-ervoirs in the hydrogeological environment, the effect on the quantity and quality of groundwater, and the potential impact on the used groundwater resources. After the construction of the reservoirs, the groundwater level of the shallow aquifer will rise, and consequently, groundwater storage will also increase. However, it is necessary to assess the sites individually; there are often potentially negative effects of future reservoirs on groundwater.

Study of stream morphological changes and its application in the design of environmentally acceptable channels

Climatic change is manifested in a number of places by significantly spatially localized torrential rainfall with a short duration, but with great inten-sity. One of the expected consequences of this type of precipitation is the occurrence of flash floods, characterized by a sharp rise from the value of the normal flow to the value of the peak flow and a rapid decrease again. The consequence of this type of short episodic floods is the initiation of morphological transformations in the beds of smaller and medium upland streams, often with devastating effects for the section of the watercourse channel. The article summarizes research on the formation and development of a scour hole in the section at the transition from a lined riverbed with fixed bed and banks to the riverbed with loose channel boundry which can be transformed morphologically in an uncontrolled manner. In this re-search, the main attention was paid to the formulation of a parametric model of the scour hole morphological development at the transition between a lined and an unlined channel. The results of this model can be used both to understand the hydraulic-morphological processes that occur at the site of a sudden river bed change, and for the practical design of restoration modifications to the river bed at the transition from a fully lined to an un-lined river bed without any protective measures, approaching the original pristine conditions.

Will summer flows in watercourses be a half lower by 2060?

The increase in potential evapotranspiration due to warming is quite often used as an indicator of ongoing and predicted changes in the hydrological balance. However, without assessing its effect in basins with different precipitation regimes, it is not correct to consider a change in potential evapo-transpiration as an increase in actual evapotranspiration or a decrease in runoff.

„Water Centre“

The research project of the Technology Agency of the Czech Republic SS02030027 „Water systems and water management in the Czech Republic in conditions of climate change“, whose guarantor is the Ministry of the Environment, tries to answer the question of whether we will continue to have enough quality water. Climate change and the associated drought, as well as human behaviour and demands threaten water, and solutions must be sought for the immediate future.

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

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)

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

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.

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

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.

Juvenile fish assemblages – appropriate tool for monitoring of the ecological status

Aquatic organisms have a very good ability to reflect the conditions of the environment they live in and, therefore, they are often used to assess the ecological status of that particular environment. of juvenile fish assemblages (0+) represent an appropriate tool for monitoring the ecological status of watercourses as they show a very rapid response to changes in environmental conditions. The goal of this study was to assess assemblages of juvenile fish (0+) at 22 sites across the Czech Republic between 2019 and 2021.

Development of pond locations in the Polabí lowland since the mid-19th century – part 1 – Pardubice region

This article focuses on mapping the development of the lowland landscape over the last 180 years, related to pressures to use lowland areas for economic purposes, including transformation of wetland habitats (specifically ponds) into arable land.  The Polabí lowland was chosen as the study area because it is currently affected by a lack of water and there is an occurrence of seasonal drying up of small watercourses. This issue will probably be of greater significance in the future, particularly in the context of the expected continued extreme climatic phenomena. Within the Polabí lowland, the results from the Pardubice region (where the biggest change in pond locations occur) are presented here. The area of all types of ponds (according to their stability) makes up 6.83 % of the study area. According to their occurrence from the Second Military Mapping (1836–1852) up to 2022, the ponds were divided into disappeared, continuous, and new. Disappeared ponds have the largest representation – about two-thirds of the total pond area according to stability. They are followed by continuous ponds, and the smallest area is 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 half of the disappeared ponds have been replaced by arable land.

Optimization network model of water management systems

The paper describes software aimed at analysing water management infrastructure and identifying critical points for water supply and assessing possible measures aimed at optimising the water supply function of the water management system. The computational procedures integrate the evaluation of the hydrological characteristics of the area, the parameters of the water management and water supply systems and the water supply requirements. The solution uses graph theory and network flow optimization (out-of-kilter algorithm is applied). The program is implemented as a PC application and equipped with a user interface.

Technical Heritage of the Elbe-Vltava Waterway

From 8th November 2022 to 31st January 2023, an exhibition entitled “Technical Heritage of the Elbe-Vltava Waterway” took place in the atrium of the Faculty of Civil Engineering of the Czech Technical University in Prague (CTU). The exhibition included exhibition panels, an interactive model of a weir lock, a video projection screen, and a stand with a web application www.lvvc.cz. The exhibition mapped the history and development of this 324 km waterway since the beginning of the 19th century, and it is expected to continue as a travelling exhibition.

Landscape changes in selected locations of the Polabí lowlands with a focus on wetlands

This article presents three typologically different sites from Polabí where large-scale wetland sites were located in the past, including ponds. These sites were chosen in order to present disappeared floodplain meadows, disappeared “field” wetlands, disappeared ponds or pond systems, and, simultaneously, to present sites where wetland habitats have been at least partially restored. The main aim was to present easily accessible archival maps, on the basis of which it is possible to assess the spatio-temporal dynamics of wetland habitats in the places of disappeared wetlands with regard to their possible restoration.

Multi-Criteria Analysis of the Dyje basin

This article deals with applications of the specific method of multicriteria analysis (MCA) and its use in the identification of areas within the Czech Republic where adaptation measures to the consequences of climate change would be most effective. MCA was chosen due to its comprehensive approach and the simplicity of working with available data in the Czech Republic. The first MCA have already been applied in the Pilsen and Pardubice Regions within the framework of the creation of the strategic document Regional Strategy of Adaptation Measures (Regionální strategie adaptačních opatření, ReSAO), whose aim was to assess the vulnerability of the entire area of these regions. The results from both strategies are expedient from the point of view of drafting adaptation measures, and it was therefore decided to use MCA as part of a larger project in the Dyje basin. In the first phase, the implemented analyses were evaluated to improve MCA for the studied area. In the second phase, MCA was applied to the area of agricultural land. Several thematic indicators were evaluated, namely surface drainage, land use, erosion risk, and occurrence of erosion events. The aim was to focus on IV order basins, in which the priority of implementing measures on agricultural land is the highest. The result was a list of IV order basins with a partial and summary assessment of problems within the total studied area of the Dyje basin.

Agroforestry and its effect on the complex of hydropedological properties of the soil

The aim of this article is to evaluate landscape retention capacity based on the use of soil protection technology at the chosen site and to compare selected hydropedological characteristics in the context of land management. Therefore, broken and intact soil samples are taken regularly and laboratory analyses are carried out. The chosen site is located in the Šardice cadastral area, Hodonín district, South Moravian region. At the chosen site it is possible to consider grass strips with one or more rows of trees as a possible agroforestry system, where temperature and humidity are measured continuously by TOMST TMS-4 moisture sensors. The results show that the way land is used and cultivated has an impact on hydropedological properties of the land. We can influence them both positively and negatively.

Planned restoration of aquatic ecosystems in Prague 4

Prague 4 district in accordance with the National Action Plan for Adaptation to Climate Change [1], Concept for Protection from the Effects of Drought of the Czech Republic [2], Strategy for Adaptation of the Capital City of Prague to Climate Change [3] and Methodology for Rainwater Management in the City [4, 5], similarly to other progressive-minded parts of Prague, is preparing investment actions to support and strengthen green-blue infrastructure in the city. One of the most visible measures with truly demonstrable effects on the support of biodiversity and water retention in the landscape is the restoration of aquatic ecosystems. In the case of the capital city of Prague and its most populous district of Prague 4, these are mainly the restoration of canalized (straightened or piped) streams, or desilting, strengthening or comprehensive restoration of ponds and small water reservoirs in a highly urbanized landscape. A specific area is newly emerging bodies of water in places where water naturally tends to be retained after longer periods of rainfall and the area thus cannot be used for any other purpose, or even in places where there was no body of water before (although here in the narrower sense of the word it is not restoration). For such areas created by human intervention in order to strengthen the diversity of aquatic and wetland vegetation, the name artificial aquatic biotope has been adopted. Let us have a look at the differences and specific pitfalls of individual restoration using three specific examples.

Historic floods on Rakovnický stream

This year, TGM WRI is planning to publish a book by Kašpárek, Elleder, Šírová, Dragoun, and Kašpárek Jr., dedicated to floods in the Rakovnický stream basin. It is primarily focused on the occurrence of floods before the start of instrumental observation, that is before 1898. Its purpose is to maximally expand knowledge about the frequency, seasonality, and most significant flood cases, their causes, extent, impact, and damage over the last 500 years.

Radioactive indicators in surface waters of the Ploučnice river basin

The Czech Hydrometeorological Institute (CHMI) is engaged in systematic monitoring and evaluation of radiological indicators in surface waters. The article describes changes in the values of radiological indicators in surface waters in the time series from 1967 to the present. The evolution of total volume alpha and beta activity, uranium concentration, and radium activity (226Ra) is described on characteristic profiles in the area of uranium-containing raw materials mining, in the vicinity of Stráž pod Ralskem, where the mining of radioactive raw materials has already been suppressed. The Ploučnice river flows through this mining area and flows into the Elbe river in Děčín near the Hřensko border crossing, where activities of radiological indicators are also monitored and documented. Following the cessation of uranium mining at the Stráž pod Ralskem deposit, uranium concentrations dropped by two orders of magnitude, and surface waters on the Ploučnice – Mimoň profile have been classified as Class I – unpolluted water for the last five years. The values of Kendall’s correlation coefficient τ for the profiles evaluated on the selected profiles during the mining period are characterized by an increasing trend (+0.7) for the indicator of total volume beta activity; after the end of mining, a decreasing trend is indicated (-0.5).

Impact of weir construction at locality Abovce (Slovakia) on groundwater levels – a case study from Slaná river basin

The construction of weirs on rivers affects the dynamics of groundwater levels. The weir built on the river Slaná in the year 2010 between the village of Abovce and Chanava brought the opportunity to study such impact due to preexisting groundwater monitoring wells of the Slovak Hydrometeorological Institute. to verify the impact of the constructed weir on groundwater dynamics in the area, records of weekly data were used ranging from 1986 to 2018. In addition, the spatial range of influenced areas was carried out using geographical information systems, and spatial interpolation techniques were used. The results showed that immediately after the construction of the weir, the groundwater level rose significantly.

Potential of areas protected for surface water storage to mitigate the impacts of climate change on drinking water supply

In the Czech Republic, areas morphologically, geologically and hydrologically suitable for surface water storage to mitigate the adverse effects of floods and droughts are defined through the General Plan for Surface Water Accu-mulation Areas. In the context of climate change, these locations create potential for possible adaptation measures. This article describes the assessment of the potential of selected sites for water supply under climate change condi-tions by means of hydrological and water balance modelling.

Small headwater catchments – spatial delimitation and their classification in terms of runoff risks

This article presents an aerial delineation of small headwater catchments up to 5 km2 in the Czech Republic. The aim was not only to present the delineation of these catchments, but also their categorization in terms of the characteristics affecting the formation of direct runoff. Direct runoff caused by torrential rainfall is a very dynamic process of episodic nature and has a major impact specifically in small catchments. The delineation of small headwater catchments, where the aforementioned processes take place, can complement the standard hierarchical classification of basins in the Czech Republic. These basins make up 80 % of the Czech Republic.

Modelling flow distribution in inlet galleries

The main objective of the article was to optimize the facilities used to distribute flows in inlet galleries, which are used not only in water treatment plants, but also in wastewater treatment plants (WWTP). While working in the field of WWTP, it was found that there are no optimized facilities in the Czech Republic or globally for uniform distribution of flows to any number of inlet branches into reservoirs of the same flow rate.  Currently, in most unregulated facilities, there are significant differences between the various inlet branches to the reservoirs. In regulated facilities, the outlets must be regulated at each change in flow rate and, for changes in the number of inlets to the reservoir (e.g., due to reservoir shutdown), each outlet must be manually adjusted (e.g., using a sluice gate) so that all inlets to reservoirs have the same flow rate. In more modern cases, the sluice is equipped with an electric motor for changing the position and a probe sensing the level. The central unit then calculates the flow rate in the individual reservoir inlets and adjusts the position of the sluice gates so that the same flow rate is achieved everywhere. The objective of the research was to optimize the distribution facility so that the inlets to the reservoirs reach similar values for the flow rate when both the inflow to the distribution facility and the number of inlet branches to the reservoirs are changed, without significant regulation at the distribution facility. In order to make the research easily applicable to as many distribution facility as possible, the most commonly used flow distribution facilities (fountain spillway, flume with outlets fitted with a sluice gate and probe for level monitoring, etc.) were selected to address the issue. Different flow conditions were simulated on the selected facilities (in different variants and shapes); after their analysis the facilities were optimized in order to achieve the most similar flows at the inlets to the individual reservoirs.

Interview with Jaroslav Pollert, professor at the Faculty of Civil Engineering at CTU and a successful Czechoslovak representative in canoeing

An interview with Jaroslav Pollert, professor of the Faculty of Civil Engineering at CTU and a successful Czechoslovak representative in canoeing, about his work as part of the Executive Committee of the International Canoeing Federation (ICF), the Czechoslovak and later the Czech Olympic Committee, about his professional career focused on the hydrodynamics of dispersion systems including, among other things, designing channels for water slalom and about his view on water management studies at Czech universities.

Irrigation – rediscovered heritage, its documentation, popularisation and protection based on the example of historical meadow irrigation systems

Objekty závlah byly budovány a fungují převážně jako součást většího nebo menšího funkčního celku. Jejich význam i z pohledu potenciální pa-mátkové ochrany tak roste s identifikací a dokumentací nejen solitérních staveb, ale zejména celých soustav/funkčních celků a popisem vazeb mezi nimi. Samostatný objekt či stavba nemusejí být nijak výjimečné, avšak jejich zapojení do většího funkčního celku může vytvářet unikátně pojaté řešení. V oboru vodního hospodářství se obzvlášť projevuje důležitost a význam kritérií, jako je hodnota typologická, hodnota technologického toku, autenticita formy a funkce, hodnota technologických a systémových vazeb s přesahem do zemědělství či průmyslu. Článek přináší informace o možnostech využití tradičních metod historického a archivního výzkumu a dokumentace lokalit, jakož i o využití moderních nástrojů pro plošně rozsáhlejší systémy, včetně metod digitalizace a digitálního zpracování podkladů.

The construction of large hydraulic structures in the context of ideas and ideologies

This paper deals with some aspects of the relationship between man and water demonstrated via the example of large hydraulic structures constructed in the Czech lands. Based on this relationship, principles of the practical functioning of ideas and ideologies, including religion, can be presented. It is not just about “pagan” cults, aiming directly at worshipping water as a living being. Christianity also significantly influenced the framework in which water management operated across the centuries and, at the same time, new ideas associated with the Enlightenment and the Industrial Revolution during the 18th and 19th centuries. A key part of the paper is focused on the topic of the construction of large hydraulic structures in the 20th century, which was particularly intensive in its second half. It also mentions political, ideological, and natural changes which were, at the beginning of the 21st century, reflected in man’s relationship with water resources and the possibilities of influencing them.

Banská Štiavnica water management system – an important UNESCO technical monument

From the 16th to the 19th century, a unique water management system was created in Banská Štiavnica and its vicinity, which served the local mines. The water management system consisted of water channels – collecting ditches, which concentrated surface water from Štiavnické vrchy (Štiavnica mountains) and brought it to the mining water reservoirs (tajchy). Tajchy are water reservoirs that were built to accumulate surface water from the collecting ditches. Water from the tajchy was discharged into water canals – transporting ditches that brought water to the shafts. Here, the water was piped into the depths of the mine, where the obtained water energy powered pumping machines that pumped groundwater out of the flooded mines. Once the groundwater was drained, the miners could continue extracting gold and silver. Water-powered processing facilities also operated in Banská Štiavnica and its vicinity, which processed the extracted
ore from the mines. For centuries, the Banská Štiavnica water management system set in motion more than a hundred water-powered devices. The system consisted of about 60 tajchy, 170 km of ditches, and 15 water tunnels.

Estimation of natural groundwater resources in hydrogeological zones in the Czech Republic under changing climatic conditions 1981–2019

In the Czech Republic, hydrogeological zones were defined as early as 1965 as a part of the regional hydrogeological survey. A hydrogeological zone (HGZ) is defined as a unit with similar hydrogeological conditions, defined tectonically and geologically, in whose territory a certain type of aquifer and groundwater circulation prevails. The boundaries of HGZs have been modified over time and their numerical hydrogeological characteristics have been determined by various methods; one of the basic characteristics is the amount of natural groundwater resources. Natural resources are the dynamic component of groundwater and are expressed in m3.s-1. They are determined by the recharge of water to the aquifer system (precipitation, groundwater overflows from other aquifers, natural infiltration of surface water, etc.). If the HGZ is hydrogeologically closed, the long-term average of its recharge from precipitation and the long-term average of baseflow can be used as an estimate of the natural groundwater resource. In the “Groundwater Rebalance Project”, estimates of natural groundwater resources in 152 hydrogeological zones in the Czech Republic were processed and are presented in the report [1]. The natural resources were determined by several different methods using data from 1971–2010 and 2000–2010. 

Impact of Teplice restoration on river basin runoff – preliminary results

As part of the project for the Ministry of the Environment of the Czech Republic dealing with the monitoring of the impact of nature­‑friendly measures on improving the hydrological regime of small river basins, the Teplice river basin in the White Carpathians has been observed. Monitoring has been taking place since 2018, the measures were implemented in 2020. Data are available for the time period before the measures were implemented and for the year 2021, on which it is possible to observe the impact of the implemented revitalization. The data show the fluctuation of the daily runoff from the river basin and its overall reduction, which is probably caused by increased evaporation from the newly formed water bodies and increased water infiltration into the underground zone. After evaluating the observed data, there was a visible reduction in the surface runoff from the basin, which may nevertheless also be caused by the low rainfall totals in 2021.

Measuring annual precipitation with a radar rain gauge in severe mountain conditions

The aim of this article is to describe the experience gained while using alternative technology for measuring annual precipitation in severe mountain conditions without a source of electrical energy. For this purpose, a Lufft WS100 radar precipitation sensor was installed in Šumava in 2020 at an altitude of 1270 m above sea level. The measurements so far have shown evident advantages; for example, maintenance free sensor, detailed measurement step, and distinction of the type of precipitation. The question remains how accurate the measurement is, when during some precipitation episodes the radar precipitation sensor probably overestimates its measurements. Accurate comparison with other measurements is difficult in these mountain ridge conditions. On the other hand, the radar sensor also gives accurate measurements during some precipitation episodes, which we verify by a non-heated tipping bucket rain gauge located within the station and also by measuring the height of the snow. Using these proxy data, systematic error was excluded. Measurements will continue for a more detailed evaluation. The radar sensor is, among other things, part of the monitoring of Kaplický potok in Boubín National Nature Reserve, where runoff is also monitored. From this point of view, information about precipitation and its type is important for the evaluation of the hydrological properties of the basin.