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.
We investigated the sorption-desorption behaviour of acid herbicide MCPA (4-chloro-2-methylphenoxy acetic acid) in five soils (denoted as A1-5), three bottom sediments (S1-3) and in two river sediments (L1-2) at two initial concentrations in aqueous solution - C0 = 0.5 and 10 mg L-1. Sorption and desorption of MCPA was measured by a batch equilibrium technique using analytical pure MCPA. There was no significant influence of the initial concentration of MCPA on its equilibrium distribution between soil/sediment and aqueous solution. The difference between distribution coefficient KD at C0 = 0.5 mg L-1 and KD at C0 = 10 mg L-1 was found only in the case of one bottom sediment (S2). Simple regression analysis between KD at C0 = 0.5 and 10 mg L-1 and soil/sediment properties indicated that the most important property which determined the variation in MCPA sorption is organic carbon (r = 0.885** and r = 0.921***, respectively). Similarly, the desorption of MCPA was inversely proportional to organic carbon content of the soils and sediments used (r = -0.821* and r = -0.888**). These observations showed that sorption-desorption behaviour of MCPA in soils and sediments was primarily controlled by organic components of the geosorbents used. Overall, the sorption extent of MCPA in soils and sediments was low (Psorp ≈ 5 - 53 %; KD = 0.131 - 2.827 L kg-1) and desorption extent was relatively high (Pdes ≈ 11 - 52 %), especially in soils and sediments with the lower organic carbon content. The experimental results and calculated values of groundwater ubiquity score GUS and relative leaching potential index RLPI imply that MCPA is very mobile in all soils and has high potential to contaminate groundwater. and Laboratórnymi metódami sme skúmali sorpčno-desorpčné správanie herbicídu MCPA (kyselina 4-chlór2-metyl fenoxyoctová) s kyslým charakterom (pKa = 3,07) v 5 vzorkách pôd (A1-5), v 3 vzorkách dnových sedimentov (S1-3) a v 2 vzorkách riečnych sedimentov (L1-2) pri dvoch koncentráciách vo vodnom roztoku - 0,5 a 10 mg l-1. Počiatočná koncentrácia MCPA vo vodnom roztoku nemala vplyv na jeho rozdelenie medzi pôdu/sediment a vodný roztok, iba v prípade 1 vzorky dnového sedimentu (S2) bol zistený rozdiel v rozdeľovacích koeficientoch KD. Sorbované množstvo MCPA v sledovaných pôdach a sedimentoch priamo úmerne záviselo od celkového obsahu organického uhlíka. Podobne, vodou desorbované (extrahované) množstvo MCPA z pôd a sedimentov vyjadrené v % (Pdes) nepriamo úmerne záviselo od celkového obsahu organického uhlíka. Tieto pozorovania dokumentujú, že sorpčno-desorpčné správanie MCPA v pôdach a sedimentoch je primárne kontrolované organickými zložkami sledovaných geosorbentov. Celkovo bol sorbovaný podiel MCPA v pôdach a sedimentoch nízky (Psorp ≈ 5-53 %; KD = 0,131-2,827 l kg-1) a desorbované množstvo relatívne vysoké (Pdes ≈ 11-52 %), zvlášť v pôdach a sedimentoch s nižším obsahom organického uhlíka. Experimentálne výsledky a vypočítané hodnoty GUS (Groundwater Ubiquity Score) a RLPI (Relative Leaching Potential Index) poukazujú na výraznú pohyblivosť MCPA v pôdach a vysokú tendenciu MCPA preniknúť do podzemných vôd.