Search

Start Over Format svazek Language Slovak Rights http://creativecommons.org/licenses/by-nc-sa/4.0/

32. An automated microinfiltrometer to measure small-scale soil water infiltration properties

Creator:
Gordon, Dennis C. and Hallett, Paul D.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
tension infiltrometer, water sorptivity, automated measurements, and small-scale infiltration measurements
Language:
Slovak
Description:
We developed an automated miniature constant-head tension infiltrometer that measures very small infiltration rates at millimetre resolution with minimal demands on the operator. The infiltrometer is made of 2.9 mm internal radius glass tube, with an integrated bubbling tower to maintain constant negative head and a porous mesh tip to avoid air-entry. In the bubbling tower, bubble formation and release changes the electrical resistance between two electrodes at the air-inlet. Tests were conducted on repacked sieved sands, sandy loam soil and clay loam soil, packed to a soil bulk density ρd of 1200 kg m-3 or 1400 kg m-3 and tested either air-dried or at a water potential ψ of -50 kPa. The change in water volume in the infiltrometer had a linear relationship with the number of bubbles, allowing bubble rate to be converted to infiltration rate. Sorptivity measured with the infiltrometer was similar between replicates and showed expected differences from soil texture and ρd, varying from 0.15 ± 0.01 (s.e.) mm s-1/2 for 1400 kg m-3 clay loam at ψ = -50 kPa to 0.65 ± 0.06 mm s-1/2 for 1200 kg m-3 air dry sandy loam soil. An array of infiltrometers is currently being developed so many measurements can be taken simultaneously.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

33. An inferentialist account of fictional names

Creator:
Lee, Byeong D.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
fictional names, inferentialist semantics, the anaphoric theory of reference, Sellars, and Brandom
Language:
Slovak
Description:
The goal of this paper is to present and defend an inferentialist account of the meaning of fictional names on the basis of Sellars-Brandom’s inferentialist semantics and a Brandomian anaphoric theory of reference. On this inferentialist account, the meaning of a fictional name is constituted by the relevant language norms which provide the correctness conditions for its use. In addition, the Brandomian anaphoric theory of reference allows us to understand reference in terms of anaphoric word-word relations, rather than substantial word-world relations. In this paper I argue that this inferentialist account has many important merits over its rival theories. One important merit is that it explains why we can use fictional names to make true statements, even if they lack bearers. As a consequence, this theory allows us to use fictional names without committing ourselves to an implausible ontology of fictional entities. Another important merit is that it provides a uniform semantic account of fictional names across different types of statements in which fictional names are involved.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

34. An influence of changing the humic acids content on soil water repellency and saturated hydraulic conductivity

Creator:
Babejová, Natália
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
water repellency, saturated hydraulic conductivity, humic acids, vodoodpudivosť, nasýtená hydraulická vodivosť, and humínové kyseliny
Language:
Slovak
Description:
An influence of changing the humic acids content on soil water repellency and saturated hydraulic conductivity was studied on soil samples of Mollic Gleysol from Cilizska Radvan in the Danubian Lowland. Water repellency was measured with the water drop penetration time (WDPT) test on original soil samples and on soil samples with increased humic acids content. Saturated hydraulic conductivity coefficient was measured on the above-mentioned samples with falling head permeameter. From the results of measuring it follows that an increasing of humic acids content in soil resulted in an decreasing of the coefficient of saturated hydraulic conductivity of the soil under study. Original soil was non-water reppelent soil. Already a small increasing of humic acids content in soil (in 17.9 % at original amount) caused that the soil became slightly or strongly water repellent in the average of soil moisture 15-30 %. At soil moisture less than 15 % time of penetration decreased probably as a result of shrinking and cracking of the soil. Water repellency of soil samples from horizon 0 - 5 cm was usually higher than water repellency of soil samples from horizon 5 - 10 cm both in case of humic acids extracted from peat and in case of humic acids extracted from the same soil from Cilizska Radvan. and Na pôdnej vzorke čiernice glejovej (ČA G) (MKSP, 2000) z lokality Čiližská Radvaň v Podunajskej nížině bol skúmaný pomocou testu času vsaku kvapky vody (WDPT test) vplyv zmeny obsahu humínových kyselin na vodoodpudivosť a nasýtenú hydraulickú vodivosť pôdy. Vodoodpudivosť bola meraná na pôvodných pôdnych vzorkách a vzorkách zo zvýšeným obsahom humínových kyselín. Koeficient nasýtenej hydraulickej vodivosti bol meraný na týchto pôdnych vzorkách metódou premenlivého hydraulického sklonu. Z nameraných výsledkov vyplýva, že nárast obsahu humínových kyselín v pôde mal za následok pokles koeficientu nasýtenej hydraulickej vodivosti študovanej pôdy. Už malé zvýšenie obsahu humínových kyselín v pôde (o 17,9 % pôvodnej hodnoty ) spôsobilo, že pôda sa stala slabo až silne vodoodpudivou vo vlhkostnom rozsahu 15-30 %. Pri pôdnej vlhkosti nižšej ako 15 % sa čas vsakovania zmenšil pravdepodobne v dôsledku zmršťovania pôdy a vzniku puklín. Vodoodpudivosť pôdnych vzoriek z horizontu 0 - 5 cm vo väčšine prípadov bola vyššia než vodoodpudivosť pôdnych vzoriek z horizontu 5 - 10 cm aj v prípade pridania humínových kyselín, extrahovaných z rašeliny, aj v prípade pridania humínových kyselín, extrahovaných z tej istej pôdy.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

35. An object-oriented overland flow solver for watershed flood inundation predictions: case study of Ulus basin, Turkey

Creator:
Turan, Burak and Wang, Keh-Han
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
flood inundation, dam break, finite volume, wet/dry, hydrograph, and object oriented programming
Language:
Slovak
Description:
This paper presents an object-oriented two-dimensional (2-D) overland flow model and its application in simulating flood flows over Ulus basin, located in the north of Turkey adjacent to the Black Sea. A new coding implementation according to the class environment created in object oriented C++ programming language is carried out in structuring and building the solver. The model is based on the Godunov type finite volume scheme on unstructured triangular meshes. A mass balance preserving wet/dry boundary solution algorithm is integrated in the numerical scheme to satisfy the positive-depth condition and minimize the numerical instability when treating the propagation of wave front in regions of dry bed. The balance between bed slope and flux terms is also preserved for still water conditions on irregular topography. The 2-D solver is verified by simulating selected dam break cases, where good agreement with measured data is achieved. For the simulation of flood flows in the Ulus basin, in general, the simulated outflow hydrograph is found to compare well with the recorded data. A selected inundation map that is extracted from the model results is also presented to show the water surface level in the Floodplain.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

36. Analysis of efficiency of pollution reduction measures in rural basin using MIKE Basin model. Case study: Olšava River Basin

Creator:
Kaiglová, Jana and Langhammer, Jakub
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
water quality, modelling, rural basins, MIKE basin, non-point pollution, and land use
Language:
Slovak
Description:
This paper presents the results of testing the applicability of the MIKE Basin model for simulating the efficiency of scenarios for reducing water pollution. The model has been tested on the Olšava River Basin (520 km2 ) which is a typical rural region with a heterogeneous mix of pollution sources with variable topography and land use. The study proved that the model can be calibrated successfully using even the limited amount of data typically available in rural basins. The scenarios of pollution reduction were based on implementation and intensification of municipal wastewater treatment and conversion of arable land on fields under the risk of soil erosion to permanent grassland. The application of simulation results of these scenarios with proposed measures proved decreasing concentrations in downstream monitoring stations. Due to the practical applicability of proposed measures, these could lead to fulfilment of the water pollution limits required by the Czech and EU legislation. However, there are factors of uncertainty that are discussed that may delay or limit the effect of adopted measures in small rural basins.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

37. Analysis of extreme hydrological events on the danube using the peak over threshold method

Creator:
Bačová-Mitková, Veronika and Onderka, Milan
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Danube River, extreme hydrological events, flood frequency analysis, peaks over threshold (POT) method, daily runoff, return period, tok Dunaja, extrémne hydrologické udalosti, frekvencia výskytu povodní, metóda POT, denný prietok, and doba opakovania prietokov
Language:
Slovak
Description:
The Peak Over Threshold Method (POT) was used as an alternative technique to the traditional analysis of annual discharge maxima of the Danube River. The POT method was applied to a time-series of daily discharge values covering a period of 60 years (1931-1990) at the following gauge stations: Achleiten, Kienstock, Wien, Bratislava and Nagymaros. The first part of the paper presents the use of the POT method and how it was applied to daily discharges. All mean daily discharges exceeding a defined threshold were considered in the POT analysis. Based on the POT waves independence criteria the maximum daily discharge data were selected. Two theoretical log-normal (LN) and Log-Pearson III (LP3) distributions were used to calculate the probability of exceeding annual maximum discharges. Performance of the POT method was compared to the theoretical distributions (LN, LP3). The influence of the data series length on the estimation of the N-year discharges by POT method was carried out too. Therefore, with regard to later regulations along the Danube channel bank the 40, 20 and 10-year time data series were chosen in early of the 60-year period and second analysed time data series were selected from the end of the 60-year period. Our results suggest that the POT method can provide adequate and comparable estimates of N-year discharges for more stations with short temporal coverage. and Príspevok sa zaoberá analýzou extrémnych hydrologických udalostí na Dunaji metódou Peak Over Threshold (POT). Metóda POT sa používa ako alternatíva určovania N-ročných prietokov k metóde ročných maxím pri analýzach extrémnych hydrologických udalostí. Pre výskyt vrcholových prietokov sa zvyčajne predpokladá Poissonova distribúcia. Základnými vstupnými údajmi pre štatistickú analýzu sú 60-ročné časové rady priemerných denných prietokov a 60-ročné rady maximálnych ročných prietokov v nami zvolených staniciach: Achleiten, Kienstock, Viedeň, Bratislava a Nagymaros - za obdobie 1931-1990. Extrémne hydrologické udalosti na Dunaji boli analyzované metódou POT, ktorá zahŕňa všetky maximálne denné prietoky povodní za dané obdobie, presahujúce zvolenú prahovú hodnotu. Na zostavenie teoretickej čiary prekročenia boli vybrané dve teoretické rozdelenia pravdepodobnosti: logaritmicko-normálne rozdelenie (LN) a Pearsonovo rozdelenie III. typu (LP III). Druhým cieľom príspevku bolo analyzovať vplyv zmeny dĺžky časového radu na odhad N-ročných prietokov. V práci boli 60-ročné časové rady údajov skrátené na 40, 20 a 10-ročné rady. V závere sme porovnali a zhodnotili získané výsledky štatistických odhadov N-ročných prietokov vo zvolených staniciach. Z výsledkov analýzy vyplýva, že metóda POT dáva pomerne dobré odhady N-ročných prietokov aj pre krátke časové rady údajov.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

38. Analysis of field-scale salinization: a comparison of different modeling approaches

Creator:
Vaughan, P.J., Shouse, P.J., Suarez, D.L., van Genuchten, M.Th., and Ayars, J.E.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
solute transport, field simulation, chloride, Unsatchem, transport rozpustených látok, simulácia v poľných podmienkach, and chloridy
Language:
Slovak
Description:
Soil and groundwater salinization are major problems for irrigated agriculture in many arid and semiarid areas of the world. Studies addressing such problems require accurate estimation of salt loadings from irrigated areas through the vadose zone to underlying groundwater. We studied Cl- transport in the vadose zone at 45 locations in a field in the San Joaquin Valley, California, through a combination of soil sampling at six depths (0-1.8 m) and numerical modeling using a coupled water flow and solute transport code (Unsatchem). Our purpose was to assess water and salt loadings from the heterogeneous field to groundwater over a two-year period, and to test applicability of the code to the data. Soil sampling in November, 1995, defined the initial water content and the Cl- concentration, and the soil hydraulic properties. Four more sampling periods, ending in November 1997, provided data for evaluating model performance. Cl- distributions in 1997 exhibited a variety of shapes including monotonically increasing or decreasing distributions versus depth, and profiles with maxima or and sigmoidal shapes. The standard modeling approach, based on the Richards equation and the convection-dispersion equation, predicted more Cl- leaching than was observed in the field. Somewhat improved predictions were obtained when the potential transpiration rate was increased by a factor of 1.5. Better leaching predictions were also obtained when the model included separate mobile and immobile water fractions, mostly by improving the profile shapes. Our study shows the importance of accurate descriptions of the lower boundary conditions, spatial variability in the water infiltration rate, and estimation of soil surface evaporation and transpiration rates. and Zasoľovanie pôdy a podzemných vôd sú hlavnými problémami pôdohospodárstva v závlahových podmienkach v mnohých arídnych a semiarídnych oblastiach sveta. Štúdie, ktoré riešia podobné problémy, vyžadujú si presné určenie zaťaženia soľami zo závlah, ktoré prechádzajú nenasýtenou oblasťou pôdy do podzemných vôd. V tejto štúdii sa zaoberáme transportom Cl- v nenasýtenej oblasti pôdy v 45 lokalitách v San Joaquin Valley, California, využívajúc kombináciu odberu vzoriek pôdy v šiestich hĺbkach (0–1.8 m) a numericakým modelovaním s využitím simulačného modelu kombinovaného transportu vody a rozpustených látok (solí) (Unsatchem). Cieľom je určenie priesaku vody a rozpustených látok z heterogénneho poľa do podzemných vôd počas dvojročného obdobia a testovanie použiteľnosti uvedeného modelu vzhľadom k vstupným hodnotám. Zo vzoriek pôdy, odobratých v novembri 1995 bolo určené počiatočné rozdelenie vlhkosti pôdy a koncentrácia Cl- , ako aj hydraulické vlastnosti pôdy. Štyri ďalšie termíny odberov, končiac v novembri 1997, poskytli údaje pre overenie modelu. Rozdelenie Cl- v roku 1997 sa vyznačovalo rozdieľnosťou tvarov, vrátane monotónne klesajúceho alebo stúpajúceho rozdelenia koncentrácií v závislosti na hĺbke, ako aj profilmi s maximom, alebo aj sigmoidálneho tvaru. Štandardný modelový prístup, založený na Richardsovej rovnici a konvektívno-disperznej rovnici, predpovedal viac vyplaveného Clako bolo pozorované v poli. O niečo lepšie výsledky boli dosiahnuté, ak sa potenciálna transpirácia zvýšila 1,5-násobne. Lepšie výsledky v prognóze vyplavovania solí boli dosiahnuté, ak model obsahoval separátne mobilnú a imobilnú vodu, predpovšetkým zlepšením tvarov vertikálnych rozdelení koncentrácií chlóru. V tejto štúdii bolo ukázané, aké je dôležité presné určenie dolných okrajových podmienok, priestorovej variability rýchlosti infiltrácie, ako aj určenie výparu z povrchu pôdy a transpirácie.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

39. Analysis of flood events in Slovenian streams

Creator:
Bezak, Nejc, Horvat, Alja, and Šraj, Mojca
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
baseflow separation, catchment characteristics, flood event, and comparative hydrology
Language:
Slovak
Description:
The detailed analysis of individual flood event elements, including peak discharge (Q), flood event volume (V), and flood event duration (D), is an important step for improving our understanding of complex hydrological processes. More than 2,500 flood events were defined based on the annual maximum (AM) peak discharge from 50 Slovenian gauging stations with catchment areas of between 10 and 10,000 km2 . After baseflow separation, the stations were clustered into homogeneous groups and the relationships between the flood event elements and several catchment characteristics were assessed. Different types of flood events were characteristic of different groups. The flashiness of the stream is significantly connected with mean annual precipitation and location of the station. The results indicate that some climatic factors like mean annual precipitation and catchment related attributes as for example catchment area have notable influence on the flood event elements. When assessing the dependency between the pairs of flood event elements (Q, V, D), the highest correlation coefficients were obtained for the Q-V pair. The smallest correlations or no correlations were observed between the Q and D variables.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

40. Analysis of flood events on small river catchments using the KINFIL model

Creator:
Kovář, P., Cudlín, P., Heřman, M., Zemek, F., and Korytář, M.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
infiltration approach, kinematic wave, GIS, rainfall-runoff models, water balance models, infiltracní prístup, kinematická vlna, and modely hydrologické bilance
Language:
Slovak
Description:
This paper deals with some ways of carrying out an analysis of a flood event using the KINFIL hydrological model on small catchments where both land use and management play a significant role, and where these human activities can influence design discharges. The combination of GIS techniques with the KINFIL model, which is conceived on physically based infiltration approach and on a kinematic wave transformation of direct runoff, provides a tool for analysing historical rainfall-runoff events, for assessing design discharges, and for simulating some hypothetical flood scenarios. KINFIL is a complex model using the correspondence of Curve Number (CN) with soil parameters and the correspondence of kinematic wave transformation with the physiographical parameters of the Všeminka catchment in Eastern Moravia (Czech Republic), which was used in the tests. Two versions of the KINFIL model (KINFIL1, KINFIL2) were implemented. The infiltration part of the model is the same in both versions. KINFIL 1 assumes a more schematic geometrization of the catchment topography, distributing the catchment area to a V-shaped form in which a main channel collects direct runoff from both side planes or segments. This is not fully in accord with the topography of the sub-catchment. KINFIL 2 is a more sophisticated version, where the topography is GIS-organized, taking fully into account the river network and its corresponding sub-catchment division. The latter version is geographically (and also physically) better based, and the results of the simulation of the July 1997 flood waves in the Vseminka experimental catchment fit better with the observed waves. All the topographical and morphological data were analysed and prepared for the KINFIL model (particularly for the KINFIL 2 version), using GIS facilities. Thus the KINFIL 2 version can be applied in future for design discharge assessment when simulating scenarios of various land uses expressing the model parameters. and Příspěvek analyzuje povodňové případy implementace hydrologického modelu KINFIL, používaného na malých povodích, kde hospodárské využití pozemku a antropogenní vlivy hrají podstatnou roli. Záměrem příspevku je informovat o možnostech využití GIS při fragmentaci malých povodí za účelem zpřesnění vstupních dat pro hydrologický model KINFIL. Kombinace GIS a KINFIL, který je fyzikálně založen na teorii infiltrace a transformace přímého odtoku kinematickou vlnou, poskytuje nástroj pro analýzu jak historických srážko-odtokových případů, tak hypotetických scénářových simulací. Model KINFIL využívá dříve odvozených vztahů mezi hodnotami čísel odtokových křivek CN a „koncepčních“ půdních parametrů (nasycené hydraulické vodivosti a sorptivity) spolu s parametry transformace na testovaném povodí Všeminky na východní Morave. Byly testovány dvě modelové verze: KINFIL 1 a KINFIL 2. Infiltrační část modelu je v obou verzích stejná. Verze KINFIL 1 je založena na schematické geometrizaci, kde povodí je V-tvaru a do hlavního toku je sváděn přímý odtok zobou stran z paralelně uspořádaných desek a každá z těchto desek je sériově (kaskádově) členěna podle sklonu svahů. Takto definované desky ale nemusí plně respektovat členění na subpovodí. Naproti tomu nový přístup KINFIL 2, který za účelem fragmentace povodí využívá prostředků GIS, plně respektuje průběh říční sítě povodí a její členění na subpovodí. Základem pro získání požadovaných parametrů modelu KINFIL 2 je digitální model reliéfu terénu (DEM). Tato verze je geograficky lépe založená a výsledky simulovaných průtoků povodně z července 1997 na experimentálním povodí Všeminky se lépe shodují s průtoky měřenými.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public