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2. Biohydrology 2009: a changing climate for biology and soil hydrology interactions
- Creator:
- Lichner, Ľubomír and Novák, Viliam
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Slovak
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
3. Comparison of daily potential evapotranspiration calculated by two procedures based on Penman-Monteith type equation
- Creator:
- Hlaváčiková, Hana and Novák, Viliam
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- potential evapotranspiration, reference crop, and Penman-Monteith equation
- Language:
- Slovak
- Description:
- Paper presents comparison of the daily reference crop (grass vegetation cover) potential evapotranspiration results calculated by the two modifications of the Penman-Monteith type equation. The first modification was published in FAO recommendation (Allen at al., 1998), PM-FAO, the second is modification according to Budagovskiy (1964) and Novák (1995), PM-BN. Both are used in soil water simulation models HYDRUS-1D and GLOBAL. Calculations were performed for frost-free seasons of the years 2000-2009, using the meteorological station Gabčíkovo (South Slovakia) meteorological data and canopy characteristics. The results indicate significant differences in daily and seasonal potential evapotranspiration. Reasons for those differences are discussed; they should be in different net radiation and aerodynamic resistance estimation methods.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4. In memoriam Prof. George J. Halasi-Kun
- Creator:
- Novák, Viliam
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Slovak
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5. Infiltration into a swelling, cracked clay soil
- Creator:
- Novák, Viliam, Šimunek, Jiří, and Van Genuchten, Martinus Th.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Swelling Soils, Soil Cracks, Water Infiltration, Mathematical Modeling, napuciavajúce pôdy, pôdne pukliny, infiltrácia vody, and matematické modelovanie
- Language:
- Slovak
- Description:
- Transient infiltration into a swelling, cracked fine-textured soil was calculated using the originally designed FRACTURE submodel (version B) of the HYDRUS-ET simulation model. The model permits changes in the dimensions of the cracks during the infiltration process. Modeling results obtained with the new model were compared with those from FRACTURE submodel (version A) assuming a stable crack system. It is shown that deforming cracks lead to higher rates of infiltration during precipitation events as compared with stable cracks. A difference of about 20 percent was estimated in our illustrative example. and Práca obsahuje výsledky matematického modelovania infiltrácie vody do pôdy s puklinami, meniacimi svoje rozmery pocas procesu, (verzia B) v závislosti na vlhkosti pôdy, ktoré sú porovnané s výsledkami, získanými pomocou modelu s konštantnými rozmermi puklín (verzia A) pocas infiltrácie zrážok. Submodel FRACTURE - verzia B, ktorá kvantifikuje infiltráciu vody do pôdy s deformujúcimi sa puklinami je súcastou modelu HYDRUS–ET. Porovnanie výsledkov modelovania pomocou oboch submodelov ukázalo, že pocas zrážkovej udalosti v tomto ilustratívnom príklade rýchlost infiltrácie do pôdy s deformujúcimi sa puklinami je asi o 20 % väcšia ako do pôdy so stabilnými puklinami. Treba poznamenat, že meranie charakteristík infiltrácie vody do pôdy s puklinami a súcasné meranie deformácií siete puklín nie je v prírode prakticky možné, preto matematické modely môžu byt použité aj ako nástroje vedeckého výskumu v numerických experimentoch.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
6. Ing. Josef Hladný, CSc, sedemdesiatrocný
- Creator:
- Novák, Viliam
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Slovak
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
7. Ing. Josef Hladný, CSc. sa dožíva 80 rokov
- Creator:
- Novák, Viliam and Šuvarinová, Olga
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Slovak
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
8. Július Šútor, Milan Gomboš, Rastislav Mati a Jozef Ivančo: Charakteristiky zóny aerácie ťažkých pôd Východoslovenskej nížiny
- Creator:
- Novák, Viliam
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Slovak
- Description:
- Autor recenze: Viliam Novák
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
9. Július Šútor, Vlasta Štekauerová: Hydrofyzikálne charakteristiky pôd Žitného ostrova
- Creator:
- Novák, Viliam
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Slovak
- Description:
- Autor recenze: Viliam Novák
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
10. Medzinárodná konferencia BIOHYDROLOGY 2006: vplyv biologických faktorov na hydrologické procesy v pôde
- Creator:
- Lichner, Ľubomír and Novák, Viliam
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Slovak
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
11. Metóda určenia režimu odberu vody z pôdy rastlinami pre potreby produkcie biomasy
- Creator:
- Havrila, Ján and Novák, Viliam
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- soil water regime, transpiration, biomass production, yield, mathematical modeling, vodný režim pôdy, transpirácia, produkcia biomasy, úroda, and matematické modelovanie
- Language:
- Slovak
- Description:
- The design and construction of amelioration systems (irrigation, drainage) should precede diagnosis of soil water regime (SWR), to estimate its need and design parameters. It means, it is needed to calculate cyclic course of so called soil water regime characteristics. As soil water regime characteristic can be used soil moisture of the soil root zone at some depth, soil water potential at certain depth, soil water content of the root zone, as they are affected by evapotranspiration and its components. Seasonal courses of soil water regime characteristics differ, therefore it is necessary to estimate statistical parameters of SWR characteristics during relatively long period of minimum twenty seasons. This paper presents method of plant transpiration regime assessment, based on seasonal canopy transpiration series, calculated retrospectively by mathematical model HYDRUS-ET. Novelty of this approach is using of the empirical relationship between the seasonal transpiration totals and biomass production (yield). Cumulative frequency distribution curve of seasonal transpiration was chosen as a basic characteristic. This approach allows to estimate cumulative frequency curves of yields and cumulative frequency of potential yields. The difference is cumulative frequency of yields optimized by irrigation system. This allows to transform expected yields increase to investment and operational price and to compare expenditure to profit. This approach is illustrated on loess soil with maize canopy during 31 seasons. and Predtým, ako sa vyprojektuje a vybuduje hydromelioračná stavba, je nevyhnutné diagnostikovať vodný režim pôdy (VRP), to znamená určiť vlastnosti cyklických chodov charakteristík VRP. Ako charakteristiky režimu vody v pôde môžu byť využité: vlhkosť koreňovej oblasti pôdy, vlhkostný potenciál vo vybraných hĺbkach pôdy, obsah vody v koreňovej oblasti pôdy, ktoré sú ovplyvnené evapotranspiráciou a jej zložkami - transpiráciou a výparom. Sezónne chody vybraných charakteristík VRP sa v jednotlivých rokoch výrazne líšia, preto je potrebné určiť štatistické vlastnosti charakteristík VRP za dostatočne dlhé obdobie, najmenej dvadsiatich rokov. Údaje pre analýzu boli získané matematickým modelovaním pohybu vody v pôde pomocou matematického modelu HYDRUS-ET. Ako základná charakteristika bola vybraná transpirácia porastu. Vlastnosti režimu odberu vody porastom určuje čiara prekročenia úhrnov transpirácie konkrétneho porastu za jeho vegetačné obdobie. Prínosom tejto práce je metóda kvantitatívneho hodnotenia vplyvu sezónnych úhrnov transpirácie na úrodu, prostredníctvom všeobecne akceptovanej empirickej závislosti medzi produkciou biomasy a úhrnom transpirácie za vegetačné obdobie. Prostredníctvom tejto závislosti boli určené čiary prekročenia úrod, potenciálnych úrod a rozdielov medzi nimi, čo reprezentuje možnosti zvýšenia produkcie biomasy hydromelioračným opatrením. Takto sa dali transformovať možné zmeny sezónnych úhrnov transpirácie na ekonomickú rovinu a porovnať ekonomický prínos zmeny VRP s nákladmi na jej uskutočnenie. Metodický postup je ilustrovaný analýzou VRP porastu kukurice počas 31 vegetačných období.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
12. Nutrients uptake by maize roots: vertical distribution of uptake rates during the vegetation period
- Creator:
- Novák, Viliam
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- plant nutrients, soil, uptake rate function, transpiration, water and solute distribution, živiny rastlín, pôda, funkcia odberu živín, transpirácia, and rozdelenie vody a rozpustených látok
- Language:
- Slovak
- Description:
- This contribution presents a proposal of semiempirical method to estimate vertical profiles of nutrients uptake rate by plant roots, based on results of field measurements of soil - plant - atmosphere continuum (SPAC). The transport of chemicals in porous media can be described by convection-dispersion equation, containing sink term, characterising the solute (nutrients) uptake by roots. To determine this sink term was the aim of presented study. The data - necessary for determination of nutrients uptake rate profiles - during plants ontogenesis were acquired by measurement in the field site with maize canopy, near Trnava locality, South Slovakia. The proposed method of vertical profiles of nutrients uptake calculation is based on the estimated direct proportionality between nutrients uptake rate (nitrogen, phosphorus and potassium) and transpiration intensity during ten days time intervals. Shorter time interval is not recommended to be utilised, because estimation errors are comparable to the changes of estimated values of nutrients concentration in plants. A nutrient uptake rates profiles can be determined using the Eq. (9), knowing water uptake rate profiles and the ratio of transpiration flux and particular nutrient uptake rate. The nutrient uptake rate profile calculated by the proposed method can be incorporated into the convection-dispersion equation and is used to model nutrient transport in the soil, taking into account uptake of particular nutrients by plants, during the vegetation period. Comparison of nitrogen uptake rates estimated from field measurements and those, calculated by the presented method shows significant differences in some cases, but seems to be applicable for mathematical modelling of nutrients uptake by plants. and Príspevok obsahuje návrh poloempirickj metódy výpočtu vertikálneho rozdelenia intenzít odberu rozpustených látok (najdôležitejších živín) porastom poľnohospodárskych plodín. Súbor údajov (chodov intenzít transpirácie počas ontogenézy rastlín a sezónnych chodov obsahu vybraných živín v pôde a v rastlinách), umožňujúcich výpočet, bol získaný z výsledkov komplexných meraní charakteristík systému pôda - rastlina - atmosféra (SPAC) v pôde s porastom kukurice v objekte bývalého Výskumného ústavu kukurice v Trnave. Predpokladajúc platnosť zistenej priamej úmernosti medzi intenzitami odberu živín (dusík, fosfor, draslík) rastlinami z pôdy a intenzitou transpirácie porastu, navrhnutá bola metóda výpočtu vertikálneho rozdelenia intenzít odberu rozpustených látok (najdôležitejších živín) porastom poľnohospodárskych plodín. Jej aplikácia umožňuje určenie odberového člena v rov. (1) a riešením tejto rovnice môžeme vypočítať zmeny koncentrácie vybraných živín v pôde, berúc do úvahy ich odber koreňmi rastlín. Odberový člen možno vypočítať pomocou rov. (9), ak poznáme vertikálne rozdelenie intenzít odberu vody koreňmi rastlín a pomer medzi transpiračným tokom a celkovou intenzitou odberu príslušného iónu porastom v danom časovom intervale. Porovnanie celkových intenzít odberu dusíka porastom kukurice, ktoré bolo určené z výsledkov poľných meraní a intenzít, vypočítaných predloženou metódou síce v niektorých prípadoch ukazuje na značné rozdiely (obr. 4), avšak v prvom priblížení je metóda vhodná na modelovanie pohybu žívín v pôde.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
13. On the role of rock fragments and initial soil water content in the potential subsurface runoff formation
- Creator:
- Hlaváčiková, Hana, Novák, Viliam, and Holko, Ladislav
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- stony soils, infiltration, stoniness, initial soil water content, and mathematical modeling
- Language:
- Slovak
- Description:
- Stony soils are composed of fractions (rock fragments and fine soil) with different hydrophysical characteristics. Although they are abundant in many catchments, their properties are still not well understood. This article presents basic characteristics (texture, stoniness, saturated hydraulic conductivity, and soil water retention) of stony soils from a mountain catchment located in the highest part of the Carpathian Mountains and summarizes results of water flow modeling through a hypothetical stony soil profile. Numerical simulations indicate the highest vertical outflow from the bottom of the profile in soils without rock fragments under ponding infiltration condition. Simulation of a more realistic case in a mountain catchment, i.e. infiltration of intensive rainfall, shows that when rainfall intensity is lower than the saturated hydraulic conductivity of the stony soil, the highest outflow is predicted in a soil with the highest stoniness and high initial water content of soil matrix. Relatively low available retention capacity in a stony soil profile and consequently higher unsaturated hydraulic conductivity leads to faster movement of the infiltration front during rainfall.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
14. Pro memoria Professor Ryszard Tadeusz Walczak (1943 - 2006)
- Creator:
- Novák, Viliam
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Slovak
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
15. Prof. Ing. Ján Benetin, DrSc. osemdesiatročný
- Creator:
- Novák, Viliam
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Slovak
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
16. Prof. Ing. Ján Benetin, DrSc.: 18. 6. 1924 - 17. 5. 2007
- Creator:
- Novák, Viliam
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Slovak
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
17. Prof. Ing. Miroslav Kutílek, DrSc. (znova) jubiluje
- Creator:
- Novák, Viliam
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Slovak
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
18. RNDr. Július Šútor, DrSc. sedemdesiatnikom
- Creator:
- Novák, Viliam
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Slovak
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
19. RNDr. Juraj Pacl, CSc. Jubiluje
- Creator:
- Novák, Viliam
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Slovak
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
20. Sensitivity of soil water content profiles in the root zone to extraction functions based on different root morphological parameters
- Creator:
- Himmelbauer, Margarita L., Novák, Viliam, and Majerčák, Juraj
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- soil, crops, water uptake, root extraction function, simulation model, and model sensitivity
- Language:
- Slovak
- Description:
- Presented are results of simulations of root water uptake applying a macroscopic model of water transport in Soil - Plant - Atmosphere - Continuum. As a simulation tool is used the software package GLOBAL, based on the solution of the one-dimensional Richards equation. The main objective is to examine the contribution of root extraction functions (sink terms) based on different root morphological parameters to the changes in the soil water content profiles during the vegetation period of three crops. The root extraction functions are estimated using dry mass, length and surface area density distributions of all (total) and the fine roots (< 0.5 mm) of spring barley, winter rye and maize. It was observed that the ''root mass'' extraction curves slightly deviate from the ''length'' and ''surface area'' ones, especially in the topsoil and for the crops with a longer vegetation period. Nevertheless, the resulted differences in the soil water content distributions were small. The role of ''fine roots'' distribution was also examined. Calculating the water storage, it was found that the deviations were within the error of direct measurements. The sensitivity of the models based on the Richard´s equation to the different root extraction functions was found to be low, which reflected in small differences in soil water content distributions. Hence, any of the studied root morphological parameters can be successfully applied for simulations of root uptake at macro scale. and Práca obsahuje výsledky simulácie odberu vody koreňmi rastlín makroskopickým modelom pohybu vody v systéme pôda - rastlina - atmosféra, ak boli funkcie odberu vody koreňovým systémom určené z rozdelení rôznych charakteristík koreňového systému. Použili sme simulačný model GLOBAL, založený na riešení jednorozmerného tvaru rovnice Richardsa. Cieľom práce bolo určiť funkcie odberu vody koreňovým systémom rastlín, s využitím rozdelenia rôznych charakteristík koreňového systému tej istej rastliny a ich vplyv na vlhkostné profily v pôde počas ontogenézy rastlín. Simulácia bola vykonaná pre tri porasty - jarný jačmeň, ozimnú raž a kukuricu. Funkcie odberu vody boli vypočítané z údajov o rozdelení hmotnosti suchých koreňov, ich mernej dĺžky a merného povrchu pre všetky korene a pre ''jemné'' korene (< 0,5 mm v priemere). Ukázalo sa, že funkcie odberu založené na rozdelení hmotnosti koreňov sa nevýrazne odlišovali od tých, ktoré boli vypočítané s použitím ''dĺžky'' a ''povrchu'' koreňov v orničnej vrstve pôdy a pre porasty s dlhším vegeračným obdobím. Aj rozdiely medzi funkciami odberu s využitím rozdelenia rôznych vlastností ''jemných'' a všetkých koreňov boli v medziach presnosti merania. Z toho vyplýva, že ľubovoľný z použitých rozdelení parametrov koreňov (hmotnosť, dĺžka, povrch) môže byť použitý na výpočet odberových funkcií pre simuláciu pohybu vody v systéme PRAT a následnú simuláciu makroskopickými modelmi, založenými na riešení rovnice Richardsa.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public