Comparison of the MODFLOW modules for the simulation of the river type boundary condition

The aim of this article is the comparison of input options of river boundary condition of MODFLOW - three-dimensional numerical simulation model of groundwater flow. The water level in stream flowing through territory of hydrogeological layer can be computed via three built-in modules: River, Stream and Streamflow-Routing. In this study the code MODFLOW is used to simulate idealized aquifer and stream. The differences between computed groundwater table showed to be minimal, thus in case of modules Stream and Streamflow- Routing they are equally usable as using module River with external one or two-dimensional simulation of surface water flow, which is more time-consuming process. However, this applies only to idealized, simplified conditions of the modeled environment. For more complex simulation of flow in streams with irregular structure of the streambed is necessary to use either an external simulation or use the Streamflow-Routing module, which includes the possibility to enter more complex hydraulic flow parameters in the model

Application of asymmetrical statistical distributions for 1D simulation of solute transport in streams

Analytical solutions of the one-dimensional (1D) advection–dispersion equations, describing the substance transport in streams, are often used because of their simplicity and computational speed. Practical computations, however, clearly show the limits and the inaccuracies of this approach. These are especially visible in cases where the streams deform concentration distribution of the transported substance due to hydraulic and morphological conditions, e.g., by transient storage zones (dead zones), vegetation, and irregularities in the stream hydromorphology. In this paper, a new approach to the simulation of 1D substance transport is presented, adapted, and tested on tracer experiments available in the published research, and carried out in three small streams in Slovakia with dead zones. Evaluation of the proposed methods, based on different probability distributions, confirmed that they approximate the measured concentrations significantly better than those based upon the commonly used Gaussian distribution. Finally, an example of the application of the proposed methods to an iterative (inverse) task is presented

Water regime simulation along Gabčíkovo – Topoľníky chanel (Vrakúň junction) case study

Gabčíkovo – Topoľníky channel is one of three main channels in the irrigation and drainage channel network of Žitný ostrov. Žitný ostrov is a lowland area in south – western Slovakia with high degree of agricultural use and thanks to its bed composed mainly of fluvial gravel sediments it is a significant storage of high quality groundwater. The Vrakúň junction location was chosen due to the presence of regulation measures (floodgates)along the boundary of the area of interest and also due to the occurrence of both agricultural and urban areas. The aim of this paper is to evaluate surface water – groundwater interactions between the channel and its surroundings considering the significant increase in volume of silts in the channel over the past years and comparison of the interaction between the current state and state with no aggradation in the channel. The simulation was done using finite – difference groundwater (MODFLOW) (Harbaugh et al., 2000) model in the Aquaveo GMS interface

Assessment of dynamic effects on spine due to different dynamic loading or various seating position in a car

The main goal of this paper is to find stress after the dynamic loading in the spine. At the beginning, it is necessary to obtain a finite element model of the spine where the stress analysis is performed. Two geometries of pathological curvature of spine are analyzed for better understanding of stress distribution in the spine. The next step is to calculate the dynamic coefficient in analyzing the dynamic effects on the spine. Measurements of dynamic effects are done with two types of trainers. In the end the different inclinations of spine in sitting position are compared

Air-conditioning of supermarket

Tématem pro bakalářskou práci je návrh vzduchotechnických zařízení pro supermarket. Teoretic-ká část práce se zabývá tématem Klimatizační systémy (vodní, vzduchové, kombinované) Praktic-ká část práce se zabývá návrhem vzduchotechnických zařízení pro obchodní prostory supermar-ketu a zázemí pro zaměstnance. Zařízení jsou navržena, aby odpovídali hygienickým, provozním a bezpečnostním požadavkůmThe topic of this bachelor's thesis is the design of air conditioning equipment for a supermarket. The theoretical part of the thesis deals with the topic of air conditioning systems (water, air or the combination). The practical part of the thesis deals with the design of air conditioning equip-ment for supermarket stores and facilities for employees. The devices are designed to meet hy-giene, operational and safety requirements.

Assessment of the Impact of Thermal Insulation Performance of a Detached House in the Zlín Disctrict on Running Expenses of this Property

¨Diplomová práce se zabývá posouzením návratnosti investic do úsporných opatření. Problematika je aplikována na běžném rodinném domě, samostatně stojícím. Posouzení je provedeno ve více variantách, aby bylo dosaženo objektivního porovnání nejvýhodnějších investic. V první části je obsáhlá teorie vysvětlující souvislosti postupů a algoritmy výpočtů. Druhá část je výpočtová, především z oblasti tepelné techniky, energetického hodnocení budov a ekonomické návratnosti investic. Třetí část je zhodnocení, které na základě nabitých zkušeností a zjištěných výsledků z práce nabízí postup, jak uvažovat v případě plánované rekonstrukce a jak zhodnotit efektivnost investic do úsporných opatření.Master´s thesis deals with an assessment of investment return in saving precurations. The issue is used on an ordinary detached family house. The assessment is done in more variants to reach an objective comparison of the most advantageous investments. In the first part there is a comprehensive theory explaining the connections of the procedures and the algorithms of the calculations. The second part is calculation, especially from the thermal engineering, energy rating of buildings and the economic return on investment. The third part is an evaluation which, on the basis of the experiences and the results from the thesis, offers a proces show to think in case of intended reconstruction and how to evaluate the efficiency of the investments in the saving precurations.

Consumption of fertilizers in districts of Slovakia in the period 2006–2015

Consumption of fertilizers in districts of Slovakia in the period 2006–2015 Water quality in the surface streams is influenced by several factors. One of important information which can help us to solve problems with quality of water in water body is a distribution of point and non-point pollution sources in a river basin and also amount of pollutants released from them to surface streams. An example of a point source of pollution is the outlet from wastewater treatment plants (industry, urban areas, farms, etc.). On the other hand the most significant non-point source of pollution is considered the application of fertilizers in agriculture. In this paper we have evaluated consumption of organic and industrial fertilizers in Slovakia in the period 2006–2015. Total (in tonnes) and average (in kg ha-1) consumption of industrial and organic fertilizers was analyzed. In monitored period, the amount of applied organic fertilizers was much higher than the amount of applied industrial fertilizers and in addition a significant part of total fertilizers consumption had nitrogenous fertilizers in a group of industrial fertilizers. In a group of industrial fertilizers during the period 2006–2015 we observed just moderately increasing in their consumption, while in the period 2010–2015 the average amount of applied industrial fertilizers per hectare of agricultural land increased by about 20 kg ha-1. On the other hand, in a group of organic fertilizers we observed a decreasing in consumption of fertilizers

An approximate method for 1-D simulation of pollution transport in streams with dead zones

Analytical solutions describing the 1D substance transport in streams have many limitations and factors, which determine their accuracy. One of the very important factors is the presence of the transient storage (dead zones), that deform the concentration distribution of the transported substance. For better adaptation to such real conditions, a simple 1D approximation method is presented in this paper. The proposed approximate method is based on the asymmetric probability distribution (Gumbel’s distribution) and was verified on three streams in southern Slovakia. Tracer experiments on these streams confirmed the presence of dead zones to various extents, depending mainly on the vegetation extent in each stream. Statistical evaluation confirms that the proposed method approximates the measured concentrations significantly better than methods based upon the Gaussian distribution. The results achieved by this novel method are also comparable with the solution of the 1D advection-diffusion equation (ADE), whereas the proposed method is faster and easier to apply and thus suitable for iterative (inverse) tasks

Sedimentace v malých vodních nádržích

V současné době roste počet malých vodních nádrží v Česku i na Slovensku, které mají dva hlavní úkoly – protipovodňová ochrana a zásoba vody pro období sucha. Tyto malé vodní nádrže se často objevují v zemědělských oblastech, kde je velký potenciál jejich využití. Problém těchto oblastí je silná eroze půdy, která vede k odnosu a následnému uložení erodovaného materiálu v nádržích či nad jinými překážkami. Takto uložené sedimenty snižují retenční kapacitu nádrže, zvyšují koncentraci chemických látek, což vše může vést ke zhoršení kvality vody v nádrži i pod ní. Tento příspěvek se zaměřuje na dvě malé nádrže vybudované v roce 2011, u kterých se od uvedení do provozu sleduje množství uložených sedimentů. Jsou zde představeny dvě různé metody, jak odvodit množství sedimentů z měření vývoje dna nádrže, včetně možné aplikace empirických erozních modelů pro stanovení potenciálního množství erodovaného materiálu. Důraz je také kladen na terénní průzkum pro odběr vzorků půdy a jejich následnou laboratorní analýzu. Takto získané informace mohou pomoci k pochopení transportních i depozičních procesů v nádrži a odpovídající přispívající ploše (povodí). Výsledky poukazují na relativně rychlé zanášení malých vodních nádrží v zemědělské krajině zejména díky intenzivním srážkovým událostem. Množství sedimentů nezávisí na typu nádrže (suchá nebo se stálou hladinou), ale na charakteru povodí (fyzicko-geografické vlastnosti území), využití území a pěstovaných plodinách.The uncontrolled reservoir siltation presents a hazard together with the rising number of reservoirs and current climate change. This paper presents the possible methodologies to measure siltation in small reservoir and how to calculate the potential soil water erosion and deposition of the contributing area. The results show that the USLE-based erosion models are suitable for estimation of erosion processes, especially USPED model, which is capable to model erosion and deposition of the material in the same time. Also, both approaches to investigate the development of the reservoir bottom were verified. The use of AUV EcoMapper is appropriate for reservoirs with stable water level between 1 and 100 meters, however the second approach is more suitable for shallow reservoirs. According to observed and modelled sediment budget of reservoirs the supposed reservoir lifetime was determined from 100 to 400 years. The siltation is much higher in the Svacenický reservoir in contrast to Němčický reservoir (Suchý creek catchment), which corresponds to bigger catchment area, higher percentage of arable land and more variable relief

Assessment of potential soil water erosion based on empirical and physicall models: the case study in the Myjava Hill Land, Slovakia

The results confirmed our opinion that the extreme rainfall events cause hazardous erosion processes, especially in the agricultural areas of the Myjava Hills. The modelled sediment yields were compared with the measured data obtained by the bathymetry measurement in the Svacenický polder located in the bottom of the Svacenický catchment. The AUV (Autonomous Underwater Vehicle) device EcoMapper was used for the mapping of bed sediments of the polder. This device is an effective tool of hydrographical survey, which investigates bathymetry of a reservoir with a high-resolution