Number of results to display per page
Search Results
1332. Lesnicko-hydrologický výzkum v beskydských experimentálních povodích
- Creator:
- Bíba, Milan, Oceánská, Zuzana, Vícha, Zdeněk, and Jařabáč, Milan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- precipitations and outflows in the Beskydy Mts., two experimental basins, 52-year long time series of measurement, forest renewal, air pollution, srážky a odtoky v Beskydech, dvě experimentální povodí, 52-leté řady měření, obnovy porostů, and znečišťování ovzduší
- Language:
- Slovak
- Description:
- Forests are an important factor to control outflows of water and also partly prevent dangerous floods. In November 1927 two small representative basins with a great difference of percentages of forest cover were set up in the Czechoslovakia to measure precipitations and ouflows during 30 years with the following forest renewal. In 1953 two small fully forested experimental basins were set up with the concept to prove the increase of water resources by forest management. After a 12 year-long calibration period the accelerated forest renewal started. Both experimental basins were better accessed by forest roads. Analyses of data fluently recorded till now show that the relationship of precipitations and runoffs depends more on natural impulses than on management methods of forests. The great scatter of climatic impulses overwhelms the consequences of methods of forest management in both basins. An important factor of outflows of water is the capacity of water retention in forest soils (around 50 mm in this area). Flood and erosion control functions of the forests become to be evident but only in a limited way. The intensity of erosion in experimental basins is effectively dampened by woods and plants. and Lesy jsou důležitým faktorem při sledování odtoků vody a částečnou prevencí proti nebezpečným povodním. V listopadu 1927 byla započata třicetiletá měření srážek a odtoků ve dvou representativních povodích s velkým rozdílem v pokrytí lesem, s následujícími lesnickými obnovami. V roce 1953 se započalo měřit ve dvou malých, plně lesnatých experimentálních povodích s důvodem ověřit přibývání vody při lesnickém hospodaření. Po dvanáctileté kalibrační době začala zrychlená lesnická obnova. Obě experimentální povodí byla lépe zpřístupněna lesními cestami. Rozbor plynule zaznamenaných dat až do teď ukazuje, že vztah srážek a odtoků je více závislý na přírodních podnětech než na metodách hospodaření. Velký rozptyl klimatických prvků překonává důsledek hospodaření v obou povodích. Důležitým faktorem odtoků vody je kapacita vodní retence lesních půd (v těchto podmínkách asi 50 mm). Protipovodňové a protierozní funkce lesů jsou evidentní, ale omezené. Intenzita eroze v experimentálních povodích je efektivně tlumena stromy a rostlinami.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1333. Lewisian-style counterfactual analysis of causation: a new solution to the overdetermination problem
- Creator:
- Goswick, Dana
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- events, causation, overdetermination, counterfactual analysis, and David Lewis
- Language:
- Slovak
- Description:
- Causal overdetermination - i.e. instances in which x, y, and z all occur and intuitively the occurrence of x alone is sufficient for the occurrence of z and the occurrence of y alone is sufficient for the occurrence of z - has long been considered a problem for counterfactual analyses of causation. Intuitively, we want to say both x and y caused z, but standard Lewisian counterfactual analysis yields the result that neither x nor y caused z. David Lewis, himself, suggested that overdetermination ought to be left as ''spoils to the victor''. I show how, if we modify Lewis’ account of events slightly, we can bring counterfactual analysis in line with our intuitions about overdetermination., Kauzální overdetermination - tj. Případy ve kterých x, y, a z všichni nastanou a intuitivně výskyt x sám je dostačující pro výskyt z a výskyt y sám je dostačující pro výskyt z - dlouho byl zvažován problém pro \ t kontrafaktuální analýzy příčin. Intuitivně chceme říci, že jak x, tak y způsobily z, ale standardní Lewisianova kontrafaktuální analýza dává výsledek, že ani x ani y nezpůsobily z. David Lewis, sám, navrhl, že nadměrné určování by mělo být ponecháno jako ,,kořist pro vítěze''. Ukazuji, jak kdybychom pozměnili Lewisův účet o událostech, můžeme přinést kontrafaktuální analýzu v souladu s našimi intuicemi o předávkování., and Dana Goswick
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1334. Limitations of non-Gricean approaches to the evolution of human communicative abilities
- Creator:
- Włodarczyk, Mateusz
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- evolution of communication, evolution of language, expressive communication, Gricean communication, and organic meaning
- Language:
- Slovak
- Description:
- In this paper, I examine two non-Gricean approaches to the evolution of human communicative abilities: Mitchell S. Green’s ac- count of organic meaning and Dorit Bar-On’s account of expressive communication. I argue that the non-Gricean approaches in question face certain problems: i) they focus on the adaptive function of communicative behaviours and ignore questions about their mechanisms, ontogeny and phylogeny; ii) the notion of organic meaning does not constitute an intermediate form between natural and non-natural meaning but should rather be understood as a special case of natural meaning; iii) the non-Gricean approaches under scrutiny cannot ex- plain the transition from dyadic to triadic communication. I also outline the differences between Gricean and non-Gricean approaches and argue against the usefulness of the non-Gricean approaches discussed in this paper in explaining the evolution of human communicative abilities.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1335. Limiting cases of modal modification: reply to Kosterec
- Creator:
- Jespersen, Bjørn
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Slovak
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1336. Linear stability analysis reveals exclusion zone for sliding bed transport
- Creator:
- Talmon, Arnold M.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- stratification, hydrotransport, transients, and bed layer
- Language:
- Slovak
- Description:
- A bend or any another pipe component disturbs solids transport in pipes. Longitudinal pressure profiles downstream of such a component may show a stationary transient harmonic wave, as revealed by a recent settling slurry laboratory experiment. Therefore the fundamental transient response of the two-layer model for fully stratified flow is investigated as a first approach. A linear stability analysis of the sliding bed configuration is conducted. No stationary transient harmonic waves are found in this analysis, but adaptation lengths for exponential recovery are quantified. An example calculation is given for a 0.1 m diameter pipeline. Also consequences for long stretches of pipe line emerged. A so far undiscovered exclusion zone is found in the I-V diagram. This exclusion zone is situated adjacent to the deposit limit velocity locus curve. This simplified physical system reveals that flow velocities should be taken about 10% greater than the calculated maximum deposit limit velocity for stable converging flow.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1337. Linkage between in-stream total phosphorus and land cover in Chugoku district, Japan: an ann approach
- Creator:
- Amiri, Bahman Jabbarian, Sudheer, K. P., and Fohrer, Nicola
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- water quality modeling, land use, total phosphorus, ANN, uncertainty analysis, modelovanie kvality vody, využívanie krajiny, celkový obsah fosforu, and analýza neurčitosti
- Language:
- Slovak
- Description:
- Development of any area often leads to more intensive land use and increase in the generation of pollutants. Modeling these changes is critical to evaluate emerging changes in land use and their effect on stream water quality. The objective of this study was to assess the impact of spatial patterns in land use and population density on the water quality of streams, in case of data scarcity, in the Chugoku district of Japan. The study employed artificial neural network (ANN) technique to assess the relationship between the total phosphorous (TP) in river water and the land use in 21 river basins in the district, and the model was able to reasonably estimate the TP in the stream water. Uncertainty analysis of ANN estimates was performed using the Monte Carlo framework, and the results indicated that the ANN model predictions are statistically similar to the characteristics of the measured TP values. It was observed that any reduction in forested area or increase in agricultural land in the watersheds may cause the increase of TP concentration in the stream. Therefore, appropriate watershed management practices should be followed before making any land use change in the Chugoku district. and Rozvoj územia často súvisí so zintenzívnením využívania krajiny a produkciou znečistenia. Dôležité je modelovanie týchto zmien a ich vplyvu na kvalitu vody v tokoch. Cieľom štúdie je určiť vplyv priestorových zmien pri využívaní krajiny a zmeny hustoty osídlenia na kvalitu vody v tokoch v čase nedostatku vody v oblasti Chugoku, Japonsko. Pri riešení sa využívajú umelé neurónové siete (artificial neural network -ANN), prostredníctvom ktorých sa určuje vzťah medzi celkovým obsahom fosforu (TP) v toku a využívaním kajiny v 21 povodiach oblasti; tento model je schopný vypočítať TP v tokoch. Analýza neurčitosti výsledkov dosiahnutých pomocou ANN bola vykonaná metódou Monte Carlo; výsledky analýzy naznačujú, že predpovede pomocou metódy ANN sú štatisticky podobné meraným hodnotám TP. Bolo zistené, že redukcia lesnatosti a zvýšenie plochy poľnohospodársky využívanej pôdy v povodí môže viesť k zvýšeniu koncentrrácie TP v toku. Je preto potrebné pred zmenou vo využívaní krajiny prijať zodpovedajúce opatrenia v manažmente krajiny, ktoré budú minimalizovať negatívne dôsledky zmien využívania krajiny.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1338. Linking soils and streams during events: response of stream water K+ concentration to soil exchangeable K+ concentration in small catchments with fragipan soils (Carpathian Foothills, Poland)
- Creator:
- Siwek, Joanna P., Szymański, Wojciech, Siwek, Janusz, Żelazny, Mirosław, and Klimek, Mariusz
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- hystereses of K+, rainfall and snowmelt events, soil exchangeable K+ concentration, fragipan, agricultural and woodland catchments, and Carpathian foothills
- Language:
- Slovak
- Description:
- The study aimed to determine the linkage between soil exchangeable potassium (K+) concentration and stream water K+ concentration during rainfall and snowmelt events in small catchments with different land use (Carpathian Foothills, Poland). The complementary geochemical and hydrochemical approach used in the study produced new information on the role of particular soil horizons and contributing areas such as hillslope or riparian areas in K+ delivery to stream channels during events. Horizons lying above the nearly impermeable fragipan (Btx) play the most important role in the process of K+ influx to streams during most event types except snowmelts with frozen soils, in all the studied catchments. In the woodland catchment, rapid flushing of K+ from the topsoil Ah horizon with higher hydraulic conductivity (Ksat) and higher exchangeable K+ concentrations than in the lying lower E horizon resulted in a clockwise hysteresis of K+ in stream water during most events. In agricultural catchments, changes in stream water K+ concentration during events were determined by distinct differences between soil exchangeable K+ concentrations on hillslopes and in riparian areas.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1339. Linking surface and subsurface properties of biocrusted and non-biocrusted habitats of fine-grained fluvial sediments (playas) from the Negev Desert
- Creator:
- Kidron, Giora J.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- available water content, loess, and soil moisture
- Language:
- Slovak
- Description:
- With biocrusts playing a cardinal role in C and N fixation in arid zones, information regarding the factors that determine their limits of growth is of uttermost importance for the study of ecosystem structure and function. This is also the case in the western Negev dunefields, where although abundant on the sandy surfaces, biocrusts are scarce on finegrained (mainly loessial) sediments, termed playas. In the Nizzana research site (NRS), visibly distinct surfaces, with and without biocrusts were noted within a single playa. In an attempt to characterize these distinct surfaces, a set of random measurements were carried out, which included measurements of crack density, microrelief and chlorophyll content of the upper 0-1 cm. Following a cluster analysis, four distinct types of surfaces (hereafter habitats) were defined, one with substantial amount of chlorophyll content which can be regarded as biocrust (P4), and three non-crusted surfaces (P1- P3). Within each type, two 50 cm-deep pits were dug and the pH, electrical conductivity (EC) and fine (silt and clay) content (FC) of samples collected at 1-5, 5-10, 10-20, 20-30, 30-40 and 40-50 cm-depth were analyzed. In addition, periodical moisture measurements were carried out (in pairs) to a depth of 0-20 cm at each surface type during 2013/14. All non-crusted habitats (P1-P3) were characterized by loessial subsurface sediments. Conversely, P4 was either characterized by loessial subsurface sediments (and in this case it was characterized by a slightly concave surface) or having a sandy subsurface (at ~5-10 cm depth). While the non-crusted surfaces exhibited low moisture content, P4 exhibited deeper and higher moisture content explained either by the more sandy sediments or by lower water loss through runoff. The findings point to the close link between surface and subsurface properties and indicate that water availability may explain biocrust establishment and growth also at the loessial playa surfaces. Biocrusts may thus serve as bioindicators for habitats with high moisture content.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1340. Lithobiont-dependent ionic composition in runoff water
- Creator:
- Kidron, Giora J. and Starinsky, Abraham
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- cyanobacteria, dew, lichens, magnesium, potassium, and Negev desert
- Language:
- Slovak
- Description:
- Rock dwelling organisms (lithobionts) such as cyanobacteria (prokaryotes) and chlorolichens (eukaryotes) abound in the Negev Desert, where they cover almost all calcareous bedrocks and rock particles (cobbles, boulders). In a small limestone watershed in the Negev Highlands, cyanobacteria inhabit the south-facing (SF) bedrocks, epilithic lichens (accompanied by endolithic lichens) inhabit the north-facing (NF) bedrocks, while endolithic lichens cover most of the cobbles and boulders in both aspects. In order to study their contribution to runoff water, a pair of runoff plots was established on habitats with cyanobacteria, endolithic lichens, and epilithic lichens. Rain and runoff were collected during the hydrological year 2006/07, and the chemical composition (Ca, Mg, Na, K, Cl, SO4, HCO3, Si) of the rain and runoff water was analyzed. Several patterns were observed: (a) as indicated by Si, more dust accumulated on the bedrocks; (b) all substrates exhibited high amounts of Ca, and HCO3; (c) while SF-bedrocks showed enrichment in K, both bedrocks (and especially the NF bedrocks), as well as the NF boulders showed an enrichment in Mg. While the enrichment in Ca and HCO3 can be explained by the contribution of the limestone parent material, the enrichment in K and Mg can be explained by the contribution of the living lithobionts, with K being mainly contributed by the cyanobacteria and Mg mainly by the epilithic lichens. Ion enrichment may therefore be aspect-dependent, reflecting the lithobiont distribution within the drainage basin, partially explaining the enrichment in K and Mg previously recorded in runoff water from the Negev.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public