The paper presents the results of hydraulic research of flow through bridge structure with free water surface and submerged inlet on a physical model. It compares current knowledge with measured data and discusses the differences.
Hydraulics, hydrology and hydrogeology
Simulation of the restoration of the meander Jordan of the Orlice River and its impact on the adjacent quaternary aquifer
An urgent issue of the water management institutions in the Czech Republic is enhancement of the water retention in the environment. One of the solutions presented by Elbe river basin authority is restoration of the meander Jordan of the Orlice River.
The article presents the results of the evaluation of the fishpond dams shape in the region of Kostelec and Kouřim in the Central Bohemian Region. The shape of the dams was assessed on the basis of a detailed digital terrain model derived from the data of Digital Relief Model of 5th Generation.
Growth and decline of fishery in Poděbrady and Nymburk Estates from the point of view of historical hydrology
This contribution presents a current occurrence of drought periods and declines of fishponds (including entire fishpond systems), in Poděbrady and Nymburk counties. Such relation is not straightforward, when we consider fishponds as reservoirs of water and energy.
The article focuses on the identification of fishponds dawn on the maps of the 1st Austrian Military Survey. The presented analyses are based mainly on manual work with old maps, because the maps used for the study lack the precision and detail needed for automated processing in the GIS environment.
Series of 16 fishponds was monitored as a part of a drainage basin of Hracholusky reservoir, which is subject of a recovery project. All the fishponds were eutrophic – hypertrophic due to wastewaters from villages and little cities (including overflows from sewers) and/or due to too intensive production of “hunters ducks” – the phenomenon that is rarely mentioned.
A rainfall simulator is a common laboratory tool for soil erosion research. Typical objective of the rainfall experiments is the evaluation of various factors on soil erosion processes, such as the effect of rainfall intensity, rainfall duration, soil characteristics, soil management, crop residues on the soil surface, plot’s slope and length.
The paper deals with the results of measurements of the weirs suitable for measuring small or minimal discharge. The research is focus on determination of the discharge coefficients for low weir heads. The results of measurements for triangular, rectangular and circular weir are present.
This contribution is a complication of the biggest floods in the Czech Republic that have occurred in the last hundred years and provides descriptions of these individual disasters.
Update of empirical relationships for calculation of free water surface evaporation based on observation at Hlasivo station
Evaporation from free water surface is one of the essential components of water circulation in nature and significantly affects the overall water balance of the catchment. Due to the complicated direct measurement, it is often calculated from formulas that require available meteorological variables as input data.
Evaporation from free water surface is one of the important factors affecting the total water balance of a catchment. Since direct measurement of evaporation is complicated, evaporation is in practice often calculated using formulas based on common meteorological variables.
The paper analyses effects of snowmaking on stream flows in the Giant Mountains, detailed analysis of runoff conditions and differences in amount of water contained in technical and natural snow. Attention is paid to possible interaction between water abstraction and water pollution.
The article deals with the hydraulic and structural assessment of a sector gate in Děčín and Český Krumlov based on the evaluation of experimental measurements performed on a physical hydraulic model In the Water Management Laboratory of the Faculty of Civil Engineering, CTU in Prague.
Evaporation from the free surface is one of the basic elements of the hydrological balance. Its average value has been changing over the years due to the progressive climate change, as is the case with other elements of the hydrological balance.
Topographic data play an important role in the hydrodynamic modelling of flood events. An accurate and precise digital elevation model (DEM) with a bathymetric description of the river channel is often required. DEMs can be derived from various data sources, e.g. ground surveying or remote sensing techniques.
Runoff generation monitoring on the hillslopes of Jizera and Šumava Mountains using tracing experiments for MIPs model
The contribution presents experiments with artificial rainfall and a tracer in the Jizera Mountains which are indispensable for hillslope modelling with MIPs (Multiple Interacting Pathways ). Experiments on 2 hillslopes in the Lužická Nisa catchment in the Jizera Mountains and on one hillslope in the Šumava Mountains are described in detail.
Determination of the extent of soil unprotected by vegetation in the period of rainstorms to assess erosion risk
The article describes the method, the source data, and the results of analyses of bare soil by remote sensing and its relation to soil erosion risk. The method was tested on the parcels of AGRA Řisuty, s. r. o. Data from the satellites Landsat 8 and Sentinel 2 were used for detecting the presence of vegetation cover on each parcel.
Assessment of changes of long-term flow characteristics for the period 2001–2015 over the reference period 1961–2000 in selected Slovak gauging stations
The period 2000 to 2015 is a period in which we have observed significant differences and extremes in the hydrological regime of Slovak flows. The Slovak Hydrometeorological Institute, in the framework of its tasks, processes a comprehensive assessment of hydrological characteristics focused on drought assessment.
In this article, water quality and the assessment of anthropogenic pollution in sediments of the middle course of the Elbe River oxbow lakes Kozelská and Vrť were studied. It is widely accepted that the oxbow lakes are extremely significant ecosystems. However, a large amount of contaminated material may deposit in these lakes. The research of lake Kozelská was chosen especially to its proximity to the chemical factory Spolana in Neratovice, which used to be the biggest source of pollution of the Elbe River.
Determination of soil loss from erosion rills by method of digital photogrammetry and method of volumetric quantification
This article presents the first results of the research focused on the recording of rill erosion, and its evaluation using the outputs of the two methods that can be used to determine the soil yield. The consequences of erosion have been documented on a selected pilot site, both as a direct method of volume quantification (using an profile meter – so called soil erosion bridge) and with the use of unmanned aircraft in close-up photogrammetry (UAV).
Increasing occurrence of drought periods in the Czech Republic has highlighted a necessity of legislation modification. At the same time, a need has emerged for tools supporting decision making and water resources management at various levels during the drought periods.
Catalogue of green water retention measures in the landscape and its application in the web map application
A catalogue of green water retention measures in landscape represents one of the results of long term project financed by the Ministry of Environment. The main goal of the catalogue was to summarize a set of measures with positive effects on water retention of landscape, with low impact on ecological status of water bodies.
Study on the assessment of the effect of nature-friendly measures in the Olešná in Pelhřimov catchment area using the BILAN, HEC-HMS and HYPE models
A catalogue of natural restoration measures was created within several research programs under Ministry of the Environment of the Czech Republic, especially in the program for hydrological draught mitigation. As a next step suitable catchments for their application were identified. With use of hydrological models, the effect of designed restoration measures on three aspects of hydrological regime was assessed.
Determining of effectiveness of the action program according to the nitrate directive in a period of climate change
The Nitrate Directive defines rules for a delimitation of vulnerable zones and sets out tools to reduce nitrate pollution. The fundamental instrument is the Action Program and the Good Agricultural Practices .
The paper presents the draft of the plan for drought and water scarcity in the Czech Republic. The plan is a basic document of drought protection. It serves to coordinate activities in a given area during drought and water shortages.
As part of the Drought project, a comprehensive monitoring of watercourses and land in their catchment areas was launched in the Czech Republic to assess the impact of the implementation of revitalization actions to protect against the effects of drought.
Past tests of nuclear weapons in the atmosphere, nuclear energy facilities and tritium of natural origin are main sources of tritium in the environment. Thanks to its presence in environment and its favourable properties, tritium is used as a radiotracer.
Mathematical models have been used in hydrology for decision making support for many years. They allow the realization of virtual experiments that can be done empirically either very difficult or not at all. The SWAT model, developed in the US, has gained world wide popularity but its application in the Czech Republic is quite rare yet.
The use of automatic samplers for detailed monitoring of substance concentrations and balance is nowadays an important part of special monitoring of surface waters. The average results of routine monitoring (consisting of point samples) are often underestimated over the real situation.
This article describes part of results of the project “QJ1520268 The new procedures of optimization systems integrated protection area in the context of their economic sustainability“. The aim is effectiveness assessment of the designed measures in the Litava basin in hydrological model created in software HEC-HMS (Hydrology Engineering center – Hydrologic modeling system).
Course of the weather in the last years shows that variability of the weather increases and this also leads to a higher frequency of floods, as well as drought. Drought, regardless of its type, means that there is a lack of water in landscape.
The Czech Republic does not sufficiently create the necessary conditions for the conceptual approach to urban drainage based on the principles of a sustainable development. The Ministry of Agriculture of the Czech Republic, responsible for the water management, ignores how much a strict implementation of a sustainable drainage system, especially the blue-green infrastructure, could positively impact urbanized areas’ adaptation to climate change.
The aim of the research is to examine attitudes and preferences of the Czechs for adaptation measures reducing impacts of floods and droughts. In spring 2016, we conducted a survey on a representative sample of the Czech population (3,666 respondents).
Based on existing phosphorus data series in the Slapy and Orlík reservoirs and their main tributaries, we reconstructed P inputs to the reservoirs from the catchment during 1961–2016 and compiled empirical models of P retention.
Odra River Alarm Modul (ORAM) will be part of the NAVAROSO project. There are no results of tracer studies of the Czech part of the Odra River in the last twenty years. That´s the reason, why tracer experiment data of the Svitava River were used for analysis.
Article is based on the amendment to Act no. 254/2001 Coll. pursuant to the wording of Act no. 150/2010 Coll., the Ministry of Environment has been charged with the task of drafting a Government regulation on the method and criteria for determining the minimum residual discharge values.
The aim of this paper is to present results of study, which was aimed to evaluate the efficiency of reservoir capacities for updated input data. The study has focused on review of storage capacity, reliability of total reservoir outflow and analysis of flood protection capacity.
Response variability of selected hydrological models to typical temporal distributions of short-term precipitation
The article presents a selection of outcomes of a three-years’ project named “Variability of Short-term Precipitation and Runoff in Small Catchments and its Influence on Water Resources Management“. Its aim was to provide to the public the newly derived typical temporal distributions of subdaily precipitation, also known as design rainfalls.
This article introduces a classification of small watersheds in the Czech Republic in terms of potential hydrological response to a set of design precipitation time series. Watershed classes as well as precipitation time series were derived as a partial result of a three-year project aimed at the design of typical soil conservation measures and small water management structures
In the field of GIS support for hydrological modelling there has been distinct evolution towards so called web services, which enable the users to obtain necessary input data for modelling in a fast and effective way. With respect to design rainfall data – one of the key component – the deficit has been considerable.