Recent studies show that biochar improves physical properties of soils and contributes to the carbon sequestration. In contrast to most other studies on biochar, the present study comprise a long-term field experiment with a special focus on the simultaneous impact of N-fertilizer to soil structure parameters and content of soil organic carbon (SOC) since SOC has been linked to improved aggregate stability. However, the question remains: how does the content of water-stable aggregates change with the content of organic matter? In this paper we investigate the effects of biochar alone and in a combination with N-fertilizer (i) on the content of water-stable macro- (WSAma) and micro-aggregates (WSAmi) as well as soil structure parameters; and (ii) on the contents of SOC and labile carbon (CL) in water-stable aggregates (WSA).
A field experiment was conducted with different biochar application rates: B0 control (0 t ha–1), B10 (10 t ha–1) and B20 (20 t ha–1) and 0 (no N), 1st and 2nd level of nitrogen fertilization. The doses of level 1 were calculated on required average crop production using the balance method. The level 2 included an application of additional 100% of N in 2014 and additional 50% of N in the years 2015–2016 on silty loam Haplic Luvisol at the study site located at Dolná Malanta (Slovakia). The effects were investigated after the growing season of spring barley, maize and spring wheat in 2014,
2015 and 2016, respectively. The results indicate that the B10N0 treatment significantly decreased the structure vulnerability by 25% compared to B0N0. Overall, the lower level of N combined with lower doses of biochar and the higher level of N showed positive effects on the average contents of higher classes of WSAma and other soil structure parameters. The content of SOC in WSA in all size classes and the content of CL in WSAma 3–1 mm significantly increased after applying 20 t ha–1 of biochar compared to B0N0. In the case of the B20N1 treatment, the content of SOC in WSAma within the size classes >5 mm (8%), 5– 3 mm (19%), 3–2 mm (12%), 2–1 mm (16%), 1–0.5 mm (14%), 0.5–0.25 mm (9%) and WSAmi (12%) was higher than in B0N1. We also observed a considerably higher content of SOC in WSAma 5–0.5 mm and WSAmi with the B10N1 treatment as compared to B0N1. Doses of 20 t biochar ha–1 combined with second level of N fertilization had significant effect on the increase of WSAma and WSAmi compared to the B0N2 treatment. A significant increase of CL in WSA was determined for size classes of 2–0.25 mm and WSAmi in the B20N2 treatment. Our findings showed that biochar might have beneficial effects on soil structure parameters, SOC, CL in WSA and carbon sequestration, depending on the applied amounts of biochar and nitrogen.
The Loess Plateau is the main source of water in Yellow River, China. After 1980s, the Yellow river water presented a significant reduction, what caused the decrease of the Yellow river discharge had been debated in academic circles. We proceeded with runoff generation mechanisms to explain this phenomenon. We built saturation excess runoff and infiltration excess runoff generation mechanisms for rainfall–runoff simulation in Jingle sub-basin of Fen River basin on the Loess Plateau, to reveal the influence of land use change on flood processes and studied the changes of model parameters under different underlying conditions. The results showed that the runoff generation mechanism was mainly infiltration-excess overland flow, but the flood events of saturation-excess overland flow had an increasing trend because of land use cover change (the increase of forestland and grassland areas and the reduction of cultivated land). Some of the model parameters had physical significances，such as water storage capacity (WM), infiltration capacity (f), evapotranspiration (CKE), soil permeability coefficient (k) and index of storage capacity distribution curve (n) showed increasing trends, and index of infiltration capacity distribution curve (m) showed a decreasing trend. The above results proved the changes of runoff generation mechanism from the perspective of model parameters in Jingle sub-basin, which can provide a new perspective for understanding the discharge reduction in the Yellow River basin.
Slurs are pejorative expressions that derogate individuals or groups on the basis of their gender, race, nationality, religion, sexual orientation and so forth. In the constantly growing literature on slurs, it has become customary to appeal to so-called “neutral counterparts” for explaining the extension and truth-conditional content of slurring terms. More precisely, it is commonly assumed that every slur shares its extension and literal content with a non-evaluative counterpart term. I think this assumption is unwarranted and, in this paper, I shall present two arguments against it. (i) A careful comparison of slurs with complex or thick group-referencing pejoratives lacking neutral counterparts shows that these are in fact very hard to distinguish. (ii) Slurs lack the referential stability of their alleged neutral counterparts, which suggests that they are not coreferential. Developing (ii) will involve introducing a new concept which I regard as essential for understanding how slurs behave in natural language: referential flexibility. I shall support my claims by looking at historical and current ways in which slurs and other pejorative terms are used, and I shall argue that both etymological data and new empirical data support the conclusion that the assumption of neutral counterparts not only is unwarranted but obscures our understanding of what slurs are, and what speakers do with them.
Conceptual degree-day snow models are often calibrated using runoff observations. This makes the snow models dependent on the rainfall-runoff model they are coupled with. Numerous studies have shown that using Snow Cover Area (SCA) remote sensing observation from MODIS satellites helps to better constrain parameters. The objective of this study was to calibrate the CemaNeige degree-day snow model with SCA and runoff observations. In order to calibrate the snow model with SCA observations, the original CemaNeige SCA formulation was revisited to take into account the hysteresis that exists between SCA and the snow water equivalent (SWE) during the accumulation and melt phases. Several parametrizations of the hysteresis between SWE and SCA were taken from land surface model literature. We showed that they improve the performances of SCA simulation without degrading the river runoff simulation. With this improvement, a new calibration method of the snow model was developed using jointly SCA and runoff observations. Further analysis showed that the CemaNeige calibrated parameter sets are more robust for simulating independent periods than parameter sets obtained from discharge calibration only. Calibrating the snow model using only SCA data gave mixed results, with similar performances as using median parameters from all watersheds calibration.
The infrared thermography has been successfully applied as a tool for high resolution imaging in different hydrological studies. This exploratory experimental study aimed at evaluating the possibility of using infrared thermography to determine the diameter of raindrops. Rain samples are collected on a pre-heated acrylic board, which is exposed to rain during an instant, and thermograms are recorded. The area of the thermal stains (''signatures'' of the raindrops) emerging on the board is measured and converted to drop diameters, applying a calibration equation. Diameters of natural raindrops estimated using this technique were compared with laser disdrometer measurements; the Nash-Sutcliffe efficiency coefficient was used for evaluating the match between the resulting histograms of drop size distribution. Results confirm the usefulness of this simple technique for sizing and counting raindrops, although it is unsatisfactory in light rain or drizzle.
Analyzing the process of keeping promise we identify its sequence structure and its phase sequences in time. This allows us to arrive at a time order principle forming according to which obligation performance cannot precede in time its sufficient or necessary conditions performance. We further observe that a given promise must always be taken as an element of a certain system of promises. As a result we review definitions of the terms sufficient condition and necessary condition as no more allowing their mutual defining, or symmetry (conversion). We try to discover the compliance rules concerning the condition - the conditioned vector, the course of events vector and the time vector. We conclude that it indicates an incorrect use if, provided the condition - the conditioned vector complies with the course of events vector, the negative time difference in the descriptive use of sentences involving either the if-then connective or the only if connective is obtained. Only when using sentences for abductive explanation with a dominating epistemic vector the negative difference of time does not indicate erroneous use; however, this is possible only for the term of sufficient condition. We further suggest reviewed definition generalization involving the terms of sufficient condition and necessary condition containing always a parameter element denot-ing a given modality type, or a particular system of rules, laws, etc. Such definition satisfies Brennan’s requirement of a ''general formal scheme'' where the notion of sufficient condition and necessary condition symmetry (conversion) does not apply., Analýzou procesu dodržení příslibu identifikujeme jeho sekvenční strukturu a její fázové sekvence v čase. To nám umožňuje dospět k principu tvorby časového řádu, podle něhož plnění závazku nemůže včas předcházet jeho dostatečným nebo nezbytným výkonovým podmínkám. Dále pozorujeme, že daný slib musí být vždy považován za prvek určitého systému slibů. Jako výsledek přezkoumáváme definice pojmů dostatečná podmínka a nezbytná podmínka, protože již neumožňují jejich vzájemné vymezení nebo symetrii (konverzi). Snažíme se zjistit, jaká pravidla se týkají podmínky - podmíněný vektor, průběh vektoru událostí a časový vektor. Došli jsme k závěru, že indikuje nesprávné použití, pokud podmínka splňuje podmínku vektoru událostí, záporný časový rozdíl v popisném použití vět zahrnujících buď spojku if-then, nebo pouze tehdy, pokud je získáno spojení. Pouze pokud použijete věty pro abduktivní vysvětlení s dominantním epistemickým vektorem, negativní časový rozdíl neznamená chybné použití; to je však možné pouze po dostatečnou dobu. Dále navrhujeme zrevidovat definici definic zahrnující podmínky dostatečné podmínky a nezbytnou podmínku obsahující vždy prvek parametru označující daný typ modality nebo určitý systém pravidel, zákonů atd. Tato definice splňuje požadavek Brennanové na ,,obecný formální systém ''.Tam, kde se nepoužije pojem dostatečná podmínka a nezbytná symetrie podmínky (konverze)., and František Gahér
The paper presents the results of sediment monitoring in a small experimental agricultural Rybárik basin near Považská Bystrica (Western Slovakia). In compare with rainfall-runoff events, during which suspended sediment concentrations increase with the flow, there is no significant relationship between discharge and suspended sediment concentrations measured during the base flow. These concentrations are considerably lower than those measured during rainfall-runoff events. It is clear, that the behaviour of suspended sediment in the small Rybárik basin is not only a function of flow energy conditions. Sediment transport rates are also a function of sediment availability. Based on suspended sediment concentrations and discharge values measured during the base flow for the hydrological year 1986/87 (1-3 day sampling interval) the annual value of suspended sediment load was calculated. The calculated load for the year 1986/87 is 2106 kg year-1 (17.6 t km-2 year-1) for the Rybárik basin. Due to missing data in the rest of the monitoring period, it was not possible to compute sediment load for other years. However, comparison of suspended sediment concentrations measured on infrequent sampling basis (7 day sampling interval approximately) over a period from April 2001 to October 2001 with concentrations measured for the same period in the year 1987 suggests weak changes in suspended sediment loads for the individual hydrological years. and V príspevku sa uvádzajú výsledky monitorovania sedimentov na malom experimentálnom povodí Rybárik pri Považskej Bystrici. V porovnaní so zrážko-odtokovými udalosťami, počas ktorých sa koncentrácia plavenín zvyšuje s prietokom, medzi prietokom a koncentráciou plavenín v podmienkach základného odtoku nie je významný vzájomný vzťah. Hodnoty koncentrácií sú podstatne nižšie ako hodnoty namerané počas zrážko-odtokových udalostí. Je zrejmé, že správanie plavenín na malom povodí Rybárik nie je len funkciou prietoku, ale aj funkciou tzv. dostupnosti sedimentov. Množstvo plavenín transportovaných v podmienkach základného odtoku počas hydrologického roka 1986/87 z povodia Rybárik, určené na základe hodnôt prietoku a koncentrácií plavenín nameraných v 1-3-dňových intervaloch bolo 2106 kg/rok (17.6 t/km2 /rok). Pre nedostatok údajov v iných rokoch monitorovaného obdobia nedalo sa vypočítať množstvo odneseného sedimentu v týchto rokoch. Napriek tomu, porovnanie hodnôt koncentrácií plavenín nameraných vo vzorkách, ktoré boli nepravidelne odoberané priemerne v 7-dňových intervaloch od apríla 2001 do októbra 2001 s hodnotami, ktoré sa vyskytli v rovnakom období v roku 1987, naznačuje nevýrazné zmeny v množstvách transportovaných plavenín počas jednotlivých hydrologických rokov.