Research of the last years pointed out that most soils are neither completely hydrophilic nor hydrophobic, but exhibit a subcritical level of water repellency (i.e. contact angle, CA > 0° and < 90°). Soil water repellency (SWR) is mainly caused by organic compounds of different origin and structure, showing the relevance of biofilms and organic coatings present at many particle surfaces. Despite the importance of SWR for hydraulic processes like preferential flow phenomena, generation of heterogeneous moisture patterns, or surface run-off generation, detailed investigations on the spatial variability of SWR at various scales have rarely been carried out. We introduce a new and easy-to-apply operation for measuring the spatial distribution of SWR using a modified sessile drop method for direct optical assessment of CA at a small scale. The specific objectives of this paper are to apply a sampling and preparation technique that preserves the original spatial arrangement of soil particles and to characterize soil wettability in terms of CA at a high spatial resolution. Results revealed that the sampling and preparation technique allows determination of CA at the millimeter scale using droplets of 1 µL volume. Direct measurement on grain surfaces of the sand fraction is possible for grain sizes > 300 µm using drop volumes down to 0.1 µL. Geostatistical evaluation showed that the measurement grid scale is below the range of spatial dependency for droplets of 1 µL volume, but not for measurements on single grains (pure nugget effect). Results show further that the small-scale differences in wettability, especially for CA < 90°, cannot be detected by the conventional WDPT test. From these findings it can be concluded that the proposed technique allows the identification of small-scale variations in wettability that may promote the formation of heterogeneous flow fields and moisture patterns in soil under unsaturated conditions.
This paper deals with the formation of snowmelt-driven floods in two experimental microbasins located in Slovakia’s highlands (300-400 m a.s.l) near the town of Povazska Bystrica, Slovakia in March 2006. The first basin (Rybarik) encompasses an area of 0.119 km2 and is used primarily for agriculture; while the Lesný basin with its catchment area of 0.0864 km2 is characterized as a forested land. The maximal specific outflow from the Rybárik basin was observed on March 28, 2006, with 281.3 l s-1 km-2, peaking at 3 p.m. with 422 l s-1 km-2. In the Lesný basin, the maximum outflow was observed on March 29, 2006, with its peak of 523 l s-1 km-2 at noon. In the second part the long-term trend of snow water equivalent (SWE) modeled by the HBV-light rainfall-runoff model in the Rybarik and Lesny microbasins were evaluated. After the model verification, the daily values of SWE for the period 1965/66-2005/06 were calculated for Rybarik and Lesný microbasins. From the results it follows, that, after a temporal decline in the maxima of snow depth and of SWE in the 1990s, SWE started to increase in 2002 again. The historically highest values of SWE were simulated in both experimental microbasins in the winter season of 2005/06. and V príspevku je analyzovaná tvorba povodňového odtoku počas povodne z topenia sa snehu v marci 2006 na príklade dvoch experimentálnych mikropovodí lokalizovaných vo vrchovinovej časti Slovenska pri Považskej Bystrici (300–400 m n.m.), konkrétne z poľnohospodársky využívaného mikropovodia Rybárik (0,119 km2 ), a zo zalesneného mikropovodia Lesný (0,0864 km2 ). Maximálny meraný špecifický odtok z povodia Rybárik bol 281 l s-1 km-2 28. marca 2006 (vrchol 422 l s-1 km-2 o 15.00 hod.). Maximálny meraný špecifický odtok z povodia Lesný 263,7 l s-1 km-2 bol zaznamenaný 29. marca 2006 (vrchol 523 l s-1 km-2 o 12.00 hod.). V druhej časti príspevku je analyzovaný dlhodobý vývoj vodnej hodnoty snehu (SWE) v povodí Rybárik a Lesný, modelovanej zrážko-odtokovým modelom HBV-light. Po kalibrácii a verifikácii modelu boli modelom vypočítané denné vodné hodnoty snehu za 42-ročné obdobie 1965/66–2005/06. Z výsledkov vyplýva, že po dočasnom poklese maxím vodnej hodnoty snehu SWE v deväťdesiatych rokoch minulého storočia od roku 2002 došlo k opätovnému zvýšeniu vodnej hodnoty snehu. V zimnej sezóne 2005/06 bola vypočítaná najvyššia hodnota SWE od začiatku pozorovaní v oboch mikropovodiach.
Application of compost is known to improve the hydraulic characteristics of soils. The objective of this study was to examine the seasonal and short-term effects of solid waste compost amendments on selected hydrophysical properties of soil during dry and rainy seasons and to explore any negative impacts of municipal solid waste compost (MSWC) amendments on soil hydrophysical environment concerning Agriculture in low-country wet zone, Sri Lanka. Eight (T1–T8) MSWC and two (T9, T10) agricultural-based waste compost (AWC) samples were separately applied in the field in triplicates at 10 and 20 Mg ha–1 rates, with a control (T0). Field measurements (initial infiltration rate, Ii; steady state infiltration rate, ISS; unsaturated hydraulic conductivity, k; sorptivity, SW) were conducted and samples were collected (0–15 cm depth) for laboratory experiments (water entry value, hwe; potential water repellency: measured with water drop penetration time, WDPT) before starting (Measurement I) and in the middle of (Measurement II) the seasonal rainfall (respectively 5 and 10 weeks after the application of compost). The difference in the soil organic matter (SOM) content was not significant between the dry and rainy periods. All the soils were almost non-repellent (WDPT = <1–5 s). The hwe of all the samples were negative. In the Measurement I, the Ii of the T0 was about 40 cm h–1, while most treatments show comparatively lower values. The ISS, SW, and k of compost amended samples were either statistically similar, or showed significantly lower values compared with T0. It was clear that all the surface hydraulic properties examined in situ (Ii, ISS, SW) were higher in the Measurement I (before rainfall) than those observed in the Measurement II (after rainfall). Water potential differences in soils might have affected the surface hydrological properties such as SW. However, water potential differences would not be the reason for weakened ISS and k in the Measurement II. Disruption of aggregates, and other subsequent processes that would take place on the soil surface as well as in the soil matrix, such as particle rearrangements, clogging of pores, might be the reason for the weakened ISS and k in the Measurement II. Considering the overall results of the present study, compost amendments seemed not to improve or accelerate but tend to suppress hydraulic properties of soil. No significant difference was observed between MSWC and AWC considering their effects on soil hydraulic properties. Application of composts can be considered helpful to slower the rapid leaching by decreasing the water movements into and within the soil.
Growing occurrence of extreme floods in the Czech Republic has attracted attention to the security of protective earthfill embankments along the rivers. A suddenly increased amount of water on the waterside slope of the embankment may have destroying or even catastrophic consequences. Predictions of seepage patterns through the earth body are usually done considering the saturated flow beneath the free water level only, neglecting the saturated-unsaturated character of the soil water dynamics within earthfill dams. The importance of water dynamics within an earth dam is known and may be addressed using numerical simulation models. In this study the solution based on transient simulation of seepage through protection levee using saturated-unsaturated theory is presented. Simulations were carried out by a two-dimensional numerical model based on Richards’ equation for water flow in porous medium. It has been shown that proposed approach is, with certain limitations, suitable for large scale engineering applications. and Vyšší pravděpodobnost výskytu extrémních klimatických jevů obrací pozornost k ochraně před následky, které tyto jevy způsobují. Zájem se soustředí na protipovodňové ochranné zemní hráze a jejich bezpečnost při povodních. Výpočet průsaku zemními hrázemi se často omezuje pouze na tu část hráze, která byla plně nasycená vodou, to znamená na plně nasycené proudění. Tento způsob modelování průsaku je dodnes považován za standardní, přestože je velmi limitující. Bez zahrnutí nenasycené části tělesa hráze je zanedbán vliv časově i prostorově proměnlivého pole vlhkostí (např. při infiltraci vody ze srážky) na polohu hladiny. V naší studii je simulováno proudění v tělese hráze s použitím numerického modelu, který umožňuje řešit proudění vody v proměnlivě nasyceném heterogenním pórovitém prostředí, s obecnými okrajovými podmínkami. Výsledky potvrdily, že přístup, který uvažuje proudění i v nenasycené části hráze, lze k řešení průsaků zemními tělesy úspěšně využít.
Water resources are usually treated as potential resources, directly exploitable by human population on the Earth. Among them, surface water and groundwater can be effectively managed for operational use. Soil water which belongs to the class of subsurface water represents the major volume of terrestrial water resources. The concept of soil water resources as a water source for biosphere was introduced recently by Budagovsky (1985) and is related to the fact, that the soil water is the most important factor of the existence and development of terrestrial vegetation. As a measure of soil water resources, Budagovsky proposed the evapotranspiration rate from the land surface during the frostless period representing the sum of water evaporation by soil and transpiration from stomata of the leaves of terrestrial plants. The primary importance of soil water is in its role as a source of water for biosphere, for the first stage of trophic chain on the Earth. In this review, the role of soil water in biotic and abiotic cycle on the Earth is discussed. Possible directions of the future study of soil water resources in relation to the environment are proposed. and Za zdroje vody na Zemi sa považujú spravidla tie potenciálne zdroje, ktoré môžu byť využité ľudstvom priamo. Priamo môžu byť využité povrchové a podzemné vody. Najväčší objem vody súše na Zemi je reprezentovaný vodami podpovrchovými. Budagovskij (1985) navrhol koncepciu pôdnych vôd ako zdroja vody pre biosféru; táto koncepcia je založená na skutočnosti, že pôdne vody sú najvýznamnejším zdrojom vody pre suchozemskú vegetáciu. Ako mieru zdrojov pôdnej vody Budagovskij navrhol evapotranspiráciu z pevniny počas bezmrazového obdobia, ako súčet výparu z pôdy a transpirácie cez prieduchy suchozemských rastlín. Najvýznamnejšou úlohou vody v pôde je to, že je zdrojom vody pre biosféru, pre prvú časť trofického reťazca na Zemi. Táto práca pojednáva o úlohe vody v pôde v biotickom a abiotickom cykle na Zemi. Sú naznačené tiež možné smery výskumu zdrojov vody v pôde v kontexte k biosfére.
In this paper, to evaluate the hydrological effects of Caragana korshinskii Kom., measured data were combined with model-simulated data to assess the C. korshinskii soil water content based on water balance equation. With measured and simulated canopy interception, plant transpiration and soil evaporation, soil water content was modeled with the water balance equation. The monthly variations in the modeled soil water content by measured and simulated components (canopy interception, plant transpiration, soil evaporation) were then compared with in situ measured soil water content. Our results shows that the modeled monthly water loss (canopy interception + soil evaporation + plant transpiration) by measured and simulated components ranges from 43.78 mm to 113.95 mm and from 47.76 mm to 125.63 mm, respectively, while the monthly input of water (precipitation) ranges from 27.30 mm to 108.30 mm. The relative error between soil water content modeled by measured and simulated components was 6.41%. To sum up, the net change in soil water (ΔSW) is negative in every month of the growing season. The soil moisture is approaching to wilting coefficient at the end of the growth season, and the soil moisture recovered during the following season.
The present article demonstrates the impact of water content in the soil profile on the formation of rain-water outflow below the soil profile. The example of the soil water regime during the vegetation season is applied to show two alternative types of soil water movement: the diffusion type flow (DTF) in drier soils and the instability-driven flow (IDF) in soils with a higher soil moisture content. This responds to two phases of soil water regime alternation - the percolation phase (IDF is taking place) and the accumulation phase (DTF is taking place). In the course of the percolation phase, the infiltrating rain water flows through the soil without causing any considerable increment of water content in the soil profile. During the accumulation phase rain water accumulates in the soil, without practically flowing through the soil profile. The soil profile functions like a reservoir filled with rain water and emptied by the withdrawal of water for plant transpiration. and Príspěvek ukazuje, jak aktuální zásoba půdní vody rozhoduje o tvorbě odtoku srážkové vody z půdy do podloží. Na příkladu vodního režimu půdy ve vegetační sezóne je vyvozeno, že střídavě dochází ke dvěma odlišným typům proudění vody v půdě: proudění difuzního typu DTF v pude sušší a nestabilitou hnané proudění (perkolační) IDF v půdě vlhčí. Tomu odpovídá střídání dvou fází vodního režimu půd - fáze perkolační (probíhá IDF) a fáze akumulační (probíhá DTF). V perkolační fázi infiltrující srážková voda půdou protéká, aniž by se v ní významně akumulovala. V akumulační fázi se srážková voda v půdě zadržuje, téměř neodtéká do podloží. Půda se chová jako nádrž, která se zaplnuje srážkovou vodou a prázdní odběrem vody na transpiraci rostlin.
This paper is a critical appraisal of the most recent attempt from cognitive science in general, developmental and evolutionary biology in particular, to understand the nature and mechanisms underlying consciousness as proposed by Anton J.M. Dijker. The proposal, briefly stated, is to view consciousness as a neural capacity for objec- tivity. What makes the problem of consciousness philosophically and scientifically challenging may be stated as follows: If consciousness has a first-person ontology and our best scientific theories have a third-person ontology, how can we come up with a satisfactory theory? Moreover, if the reduction of one to the other is impossible, what are we supposed to do? By neglecting what Chalmers calls the ''hard problem'' of consciousness, Dijker’s proposal seems unable to respond to the foregoing questions, and these questions, I maintain, are the very motivations that most of us have when we inquire about consciousness., Tento článek je kritickým posouzením posledního pokusu o kognitivní vědu obecně, zejména vývojové a evoluční biologie, pochopit podstatu a mechanismy, které jsou základem vědomí, jak navrhl Anton JM Dijker. Návrh, stručně řečeno, je vnímat vědomí jako neurální schopnost objektivity. Co dělá problém vědomí filozoficky a vědecky náročný, lze říci následovně: Pokud má vědomí první ontologii člověka a naše nejlepší vědecké teorie mají ontologii třetí osoby, jak můžeme přijít s uspokojivou teorií? Pokud je navíc redukce jednoho na druhého nemožná, co máme dělat? Zanedbáním toho, co Chalmers nazývá ,,tvrdým problémem'' vědomí, se zdá, že Dijkerův návrh nedokáže odpovědět na výše uvedené otázky, and John Ian K. Boongaling
In this short paper, I focus on several properties of the so-called Hybrid View of Fictional Characters. First, I present the theory to be discussed. Subsequently, I present several remarks on the consequences of the theory, mainly the problem of identifying fictional characters and the problem of modal properties of sentences containing fictional names.