Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 6

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1

Numerical simulations in the mala nitra stream by 1D model

100%
Szomorova L., Halaj P.
Acta Scientiarum Polonorum. Formatio Circumiectus
|
2015
|
tom 14
|
nr 2
The development of the computer technologies enables us to solve the ecological problems in water management practice very efficiently. Hydrodynamical models which simulating transport of pollution in surface water are very demanding on input data and calculation time, but on the other side, they are able to simulate detailed effect of dispersion in surface waters. The paper deals with 1-dimensional numerical model HEC-RAS and its response on various values of dispersion coefficient. This parameter is one of the most important input data for simulation of pollution spreading in streams. Getting fair value, however, is in practice very difficult. One option is the most accurate simulation of tracer experiments carried out on the ground on the natural surface flow. For the pilot application was selected flow Small Nitra. Of longitudinal dispersion coefficient in the flow, or the flow of a similar nature (with and limit the rate of flow), were in the range 0.05 to 2.5 m2 · s–1. The next task was carrying out the model sensitivity analysis, which means to evaluate input data influences, especially longitudinal dispersion coefficient, on outputs computed by 1-dimensional simulation model HEC-RAS. Sensitivity analysis model HEC-RAS also showed its adequate response to changes of the input parameter. Given the present results it can be stated that the HEC-RAS model responds to changes in the values of the longitudinal dispersion coefficient appropriately. HEC-RAS model has demonstrated its applicability to simulation of pollution in streams, and therefore is an appropriate tool for decision making related to the quality of water resources.
2

Effect of the two soil tillage systems on infiltration characteristics

100%
Nozdrovicky L., Halaj P.
Bibliotheca Fragmenta Agronomica
|
1997
|
tom 2B
3

Modelling seasonal changes of longitudinal dispersion at the Okna River

81%
Manina M., Halaj P., Jurik L., Kaletova T.
Acta Scientiarum Polonorum. Formatio Circumiectus
|
2020
|
tom 19
|
nr 1
Aim of study The problem of investigation of pollution transport along watercourses is not new, but since it is so complex there is still space for fine-tuning in order to apply it to individual watercourses. This study presents an opportunity to determine a value of longitudinal dispersion and is focused on comparing seasonal variation of the longitudinal dispersion predetermined by natural conditions of the river aquatic zone. Material and methods The dispersion of a pollutant tracer was simulated by HEC-RAS model and by one-dimensional advection-diffusion equation. Longitudinal dispersion coefficient was determined based on of tracer experiments (2 kg NaCl in 10 l H₂O) carried out in March, August, and October 2019. Both methods were applied to the Okna River in the Eastern Slovak Lowland. Result and conclusions Result showed that HEC-RAS modelling correlated to changes of dispersion and vegetation in the river. During the year, the longitudinal dispersion coefficient for Okna river estimated by the equation remained in a range from 0.093 to 1.08 m² ·s⁻¹, and when estimated using the HEC-RAS, from 0.220 to 1.850 m² ·s⁻¹. Results could represent different values of longitudinal dispersion simulated by the model or the equation. The obtained coefficients have a broad range of applications. The main use of these is as input data in the simulation of the spread of accidental pollution in rivers. Also, they can be applied to streams with similar characteristics. Results demonstrated an important role of seasonal variation of longitudinal dispersion coefficient that must be taken into account in the simulation of pollution spreading in rivers.
4

Reed beds in the wetland region in Slovakia

81%
Jurik L., Kaluz K., Halaj P.
Zeszyty Naukowe Akademii Rolniczej w Krakowie. Inżynieria Środowiska
|
2003
|
tom 24
5

Evaluation of surface water in Zitava catchment under aspect of anthropogenic impact

81%
Huska D., Krupova K., Halaj P., Mandalova K.
Acta Scientiarum Polonorum. Formatio Circumiectus
|
2013
|
tom 12
|
nr 3
Water quality in streams primarily affects human. A recent assessment of the characteristics of environmental indicators in the three sub-catchments basins Drevenica, Čerešňový Creek and Žitava (District Zlaté Moravce), we showed this effect. The sixteen villages in the sub catchments do not expect an increase in demographic trends, even a decrease in population compared to year 2000 to 228 people. In terms of water consumption in the villages we have seen that the consumption is even smaller than the specified minimum hygiene. Four municipalities haven’t own public water, are connected to group water conduit Zlaté Moravce. Average water consumption in 2010 was 68.84 liters · s–1 · day–1. The removal and treatment of waste water situation is different in each sub catchments. In the sub catchments Drevenica one of four communities has built a wastewater treatment plant, the Čerešňový Creek from four municipalities, three with treatment plant. In Žitava basins of the seven municipalities have three community wastewater treatment plants, one is under construction and one is connected to the existing sewerage treatment plant. Status of water quality in river basins also affects non-point sources of pollution. The largest percentage of acreage in the villages is currently agricultural land. In the Drevenica basin is agricultural land 51.12%, in the Čerešňový Creek basin 53.09% and 46.38% Žitava basins.
6
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Environmental effects of temperature rise and long periods without precipitation on soil processes – case study for southern Slovakia

71%
Jurik L., Halaj P., Mosiej J., Pokryvkova J., Sedmakova M.
Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation
|
2018
|
tom 50
|
nr 3
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.