In recent years the issue of the natural hydrological and meteorological time series fluctuation has been discussed more and more intensively. As the series of measured hydrological and climatological data become longer and easier worldwide accessible it is possible to deal with a large amount of historical data in their complexity. Handling these data we cannot go without new methods of mathematical statistics and mathematical analysis. In the study some methods of the long-term trends identification in the hydrological time series are presented. Apart from the classical methods, like that of moving averages, the paper focuses in detail on the Hodrick-Prescott (HP) filter. The HP filter is applicable to the trend analysis of the long-term hydrological time series. Next, a new method of the period length identification, the combined periodogramm method, is theoretically developed. Using this method the long cycles length identification becomes more precise. Here, the cycle is considered to be long when it takes the length of about 1/6 to 1/3 of the measured time series. Identification of such long cycles is important with respect to the future hydrospherical processes forecast. Results of application of these methods to the Slovak hydrological time series are presented in the second part of the study. and V posledných rokoch sa začína čoraz viac diskutovať na tému prirodzených fluktuácií hydrologických a meteorologických radov. So stále sa predlžujúcimi radmi meraných hydrologických a klimatických údajov a zlepšujúcim sa prístupom k meraným údajom na celom svete možno komplexnejšie spracovať veľký počet historicky nameraných časových radov. Pri spracovávaní týchto údajov sa nezaobídeme bez rozvoja nových metód štatistiky a matematickej analýzy. V predloženej štúdii boli opísané metódy identifikácie dlhodobého trendu hydrologických radov. Popri už klasických metódach (metóde kĺzavých priemerov) bol v tejto práci rozpracovaný Hodrickov-Prescottov (HP) filter. HP filter možno aplikovať na analýzu trendu dlhodobých ročných hydrologických časových radov. Ďalej bola v štúdii teoreticky rozpracovaná nová metóda identifikácie dĺžky periód časových radov - metóda kombinovaného periodogramu. Uvedená metóda spresňuje identifikáciu dĺžky dlhých cyklov, teda cyklov s dĺžkou okolo 1/6 až 1/3 meraného časového radu. Práve identifikácia týchto dlhých cyklov je veľmi dôležitá pri odhade budúceho vývoja hydrosféry. Praktické použitie uvedených metód na slovenských hydrologických radoch je prezentované v druhej časti štúdie.
In the second part of the paper long-term trends and cyclicity in hydrological time series are identified using both the Hodrick-Presoctt (HP) filter and the combined periodogram. The HP filter seems to be a good tool for analyzing annual time series. It clearly identifies the decrease in the Slovak rainfall time series 1900-1990 and the increase in those of 1990-2000. Using the combined periodogram method oscillation cycles in the discharge time series of main Slovak rivers were identified. These cycles are likely to be characteristic for all Slovak rivers in general. This means the discharge time series are not stationary, they involve a cyclical component. To calculate hydrological characteristics it is necessary to have such a sufficiently long time series that involves both complete wet and dry periods. Because of existence of an about 29 year cycle, a period consisting of 30 years is very suitable. From the long-term point of view, both Danube and Morava Rivers possess steady trends while in the Bodrog and Vah rivers a decrease in discharge occurred during the XX Century. This decrease was mainly due to lower annual rainfalls in Slovakia. When determine long-term discharges, an oscillation of wet and dry periods should be taken into account. The trends should be determined for closed cycles, i.e., either from minimum to minimum or from maximum to maximum. From the long-term trends analysis it follows that the linear trend is not adequate to extrapolate the hydrological time series to the future. and V druhej časti štúdie je identifikovaný dlhodobý trend a cyklickosť slovenských hydrologických časových radov použitím Hodrickovho-Prescottovho (HP) filtra a metódou kombinovaného periodogramu. HP filter sa ukázal byť dobrým nástrojom na analýzu časových radov ročných údajov. Zreteľne identifikuje pokles zrážkových úhrnov na územie SR v období 1900-1990 a nárast úhrnov v rokoch 1990-2000. Metódou kombinovaného periodogramu boli identifikované cykly kolísania prietokových radov najvýznamnejších slovenských tokov. Je pravdepodobné, že tieto cykly sú charakteristické pre všetky slovenské toky. Prietokové rady zahŕňajú v sebe cyklickú zložku. Pri výpočtoch hydrologických charakteristík je potrebné hydrologické charakteristiky počítať z dostatočne dlhých radov zachytávajúcich celý cyklus - mokré i suché obdobie. Tridsaťročné obdobie na výpočet hydrologických charakteristík tokov je vzhľadom na existenciu ca 29-ročného cyklu veľmi vhodné. Z dlhodobého hľadiska Dunaj a Morava majú vyrovnaný trend vodnosti, v Bodrogu a vo Váhu došlo v 20. storočí k poklesu odtoku. Na tomto poklese majú najväčší podiel nižšie ročné zrážkové úhrny na územie SR. Pri určovaní dlhodobých trendov prietokov je potrebné brať do úvahy cykly striedania sa suchých a mokrých období. Vývojové trendy je potrebné určovať za obdobia uzavretých cyklov - od minima po minimum, alebo od maxima po maximum. Z analýzy dlhodobých trendov vyplýva, že použitie lineárneho trendu nie je vhodné na extrapoláciu hydrologických radov do budúcnosti.
The paper presents relationship between the Standardised Precipitation Index (SPI) and physiological responses of individual trees in a beech stand using an example of an experimental plot in Bienska valley (Zvolen, Slovakia). SPI is a widely used tool for monitoring both short-term and long-term droughts, and for the assessments of drought impacts on agriculture. Due to the complex ecosystem bonds, monitoring of drought in forests often requires a sophisticated technological approach. The aim of the paper was to correlate the SPI on the physiological responses of trees that were recorded during the performed physiological research (sap flow, and stem circumference increment) at the site in the growing seasons (May to September) of the years 2012-2014. The results revealed a relationship between the index and the physiological responses, although the problem with the impact of other environmental factors has also come up. The secondary correlation, in which soil water potential that significantly affects physiological responses of forest tree species was used as a dependent variable, showed a tighter relationship with the SPI. We found the highest correlation between the soil water potential and the values of SPI aggregated for five weeks. This indicates that the beech forest has a five week resistance to drought stress. The results also enable simple monitoring of the initiation of the drought stress by applying SPI for five weeks.
In the realm of the philosophy of sounds and auditory experience there is an ongoing discussion concerned with the nature of sounds. One of the contestant views within this ontology of sound is that of the Property View, which holds that sounds are properties of the sounding objects. A way of developing this view is through the idea of dispositionalism, namely, by sustaining the theory according to which sounds are dispositional properties (Pasnau 1999; Kulvicki 2008; Roberts 2017). That portrayal, however, is not sufficient, as it has not inquired the metaphysical debates about dispositions beyond the conditional analysis. In this paper, I try to advance this view by including recent developments (for instance Bird 2007; Vetter 2015) in the field of dispositionalism and I analyse whether this new version can sort out known and new objections to Property View.
The debates over the problem of faultless disagreement have played a major role in shaping the landscape of today’s semantic theories. In my paper, I argue that even though the existent contextualism-friendly proposals explain a lot of disagreement data by specifying various ways in which speakers may use subjective predicates, neither provides a satisfactory account which would explain what all the subjective disagreements have in common. In particular, what is lacking is an explanation of the persistent autocentric cases (Lasersohn 2004), i.e., disagreements in which each speaker utters a subjective sentence while openly and knowingly occupying his or her own perspective. In my paper, I offer a solution which consists in supplementing the standard contextualist semantics with an explanation of this most problematic class of cases, which is possible due to redescribing the phenomena in speech act nomenclature.
Results of cadmium sorption and desorption, as well as distribution coefficients of cadmium in the soils from the Danubian Lowland and from Veľký Ďur (neighbourhood of the nuclear power plant Jaslovske Bohunice) are presented in this study. It was found that Cd adsorption is high in studied soils already after the one-minute lasting Cd-soil contact. The results obtained show that the highest sorption of cadmium is in the loamy-sand soil from Kalinkovo (99.75 %). Zeolite application was the most effective in the loam soil from Macov. Sorption of cadmium in this soil increased by 1.45%. The presence of zeolite in chosen soil samples influenced Cd desorption, too. In loamy-sand soil from Kalinkovo cadmium desorption decreased by 50 % after zeolite application. Sorption experiments with radionuclides (85Sr and 137Cs) were conducted on brown earth from the site Velľký Ďur. The 137Cs sorption is very high in studied soil. Zeolite is more effective in the case of 85Sr. Desorption of radiostrontium decreased by 50% after zeolite application. and V práci sa prezentujú výsledky sorpcie, desorpcie a hodnoty rozdeľovacieho koeficientu kadmia vo vybraných vzorkách pôd Podunajskej nížiny a hnedozeme z lokality Veľký Ďur. Kadmium je silne sorbované sledovanými pôdami už po 1 minúte trvania kontaktu. Najvyššia sorpcia sa pozorovala u hlinito-piesočnatej pôdy z lokality Kalinkovo, kde pomerné adsorbované množstvo S kadmia bolo 99,75 %. Aplikácia zeolitu sa najviac prejavila u hlinitej pôdy z Macova, kde sa pomerné adsorbované množstvo S kadmia zvýšilo o 1,45 %. Zeolit ovplyvnil aj desorpciu naviazaného kadmia v sledovaných pôdnych vzorkách. Najviac kadmia sa desorbovalo z hlinito-piesočnatej pôdy z Kalinkova a aplikácia zeolitu znížila pomerné desorbované množstvo kadmia na menej ako polovicu. Sorpčné experimenty s rádionuklidmi (85Sr a 137Cs) boli vykonané na hnedozemi z lokality Veľký Ďur. 137Cs je už samotnou pôdou sorbované takmer na 100 % a prítomnosť zeolitu už sorpciu prakticky nezvyšuje. Zeolit zvyšuje sorpciu hlavne u rádiostroncia. Desorpcia stroncia po aplikácii zeolitu sa znížila o 50 %.
In response to the continually increasing sediment concentrations in rivers and lakes, the Ethiopian government is leading an effort where farmers are installing soil and water conservation measures to increase infiltration and reduce erosion. This paper reports on findings from a four year study in the 95 ha Debre Mawi watershed where under the government led conservation works, mainly terraces with infiltration furrows were installed halfway in the period of observation. The results show that runoff volume decreased significantly after installation of the soil and water conservation practices but sediment concentration decreased only marginally. Sediment loads were reduced mainly because of the reduced runoff. Infiltration furrows were effective on the hillsides where rain water could infiltrate, but on the flat bottom lands that become saturated with the progress of the monsoon rain, infiltration was restricted and conservation practices became conduits for carrying excess rainfall. This caused the initiation of gullies in several occasions in the saturated bottomlands. Sediment concentration at the outlet barely decreased due to entrainment of loose soil from unstable banks of gullies in the periodically saturated bottom areas. Since most uphill drainage were already half filled up with sediments after two years, long term benefits of reducing runoff can only be sustained with continuous maintenance of uphill infiltration furrows.
We apply the Linear Storage Model (LSM) to simulate the influence of the evapotranspiration on discharges. High resolution discharge data from two small catchments in the Czech Republic, the Teply Brook and the Starosuchdolsky Brook catchment are used. The results show the runoff process is simpler in a deeper valley of the Starosuchdolsky catchment where the soil zone is deeper and the valley bottom recharges runoff even during very dry periods. Two-soil zone model is adequate to simulate the diurnal runoff variability. Three-soil zone model is needed in the Teply Brook catchment due to the absence of water transport in the most-upper soil zone. Time delays between minimum and maximum discharge during the day reach up to about 20 hours. Evapotranspiration and hydraulic resistances are as high as 14% of catchment daily runoff in the urbanized Starosuchdolsky Brook catchment and 25% of catchment daily runoff in the forested, less impacted Teply Brook catchment.
This paper explores the impacts of reconfiguration and leaf morphology on the flow downstream of a flexible foliated plant. 3D acoustic Doppler velocimetry and particle image velocimetry were used to experimentally investigate the hydrodynamic interaction between a foliated plant and the flow, testing two plants with different leaves morphology under different bulk flow velocities. The model vegetation was representative of riparian vegetation species in terms of plants hydrodynamic behavior and leaf to stem area ratio. To explore the effects of the seasonal variability of vegetation on the flow structure, leafless conditions were tested. Reconfiguration resulted in a decrease of the frontal projected area of the plants up to the 80% relative to the undeformed value. Such changes in plant frontal area markedly affected the spatial distributions of mean velocity and turbulence intensities, altering the local exchanges of momentum. At increasing reconfiguration, the different plant morphology influenced the mean and turbulent wake width. The leafless stem exhibited a rigid behavior, with the flow in the wake being comparable to that downstream of a rigid cylinder. The study revealed that the flexibility-induced reconfiguration of plants can markedly affect the local distribution of flow properties in the wake, potentially affecting transport processes at the scale of the plant and its subparts.
Changes of steady state water flow rates and the bromide breakthrough were observed in laboratory infiltration experiments done on a sample of compacted sand and on an undisturbed soil sample (Eutric Cambisol). Infiltration-outflow experiments consisted of series of ponded infiltration runs with seepage face boundary condition at the lower end of columns. The initial water contents were different for each run. The results of the experiment done on an undisturbed soil column showed that the flux rates and water contents measured during quasi-steady state differ between infiltration runs. This finding contradicts the standard theory. The fluctuations of the water content during the steady state flow can be ascribed to the variations in volume of the entrapped air. Similarly, bromide breakthrough curves performed during the steady state flow runs differ for the undisturbed soil sample. The same behaviour was not observed in the sample of homogeneous sand. Computer tomography was utilized to characterize the structure of the undisturbed soil sample with focus on potential preferential flow pathways. To formulate more general conclusions, the infiltration outflow and bromide solute transport experiments have to continue with the aim to collect a representative set of data. and Studie sleduje změny ustálených rychlostí proudění a průnikových čar bromidu na vzorku zhutněného písku a na neporušeném vzorku půdy ze skupiny kambisolů. Experimenty sestávaly ze série výtopových infiltrací na horním okraji a s výronovou plochou na spodním okraji vzorků. Počáteční vlhkost byla pro jednotlivé infiltrační běhy různá. Výsledky experimentu uskutečněného na neporušené půdě ukazují, že se vlhkosti a rychlosti proudění během ustáleného proudění lišily pro jednotlivé infiltrační běhy. Tento efekt není ve shodě se standardní teorií. Změny vlhkosti během ustáleného proudění mohou být způsobeny přítomností uzavřeného vzduchu. Pro neporušený půdní vzorek se lišil také tvar průnikových čar bromidu, měřených během ustáleného proudění. Oba efekty nebyly pozorovány pro vzorek zhutněného písku. Počítačová tomografie byla použita k popisu struktury neporušeného půdního vzorku se zaměřením na přítomnost potenciálních cest preferenčního proudění. K tomu, aby bylo možno formulovat obecné závěry, bude nutné získat reprezentativní soubor dat pomocí zde představeného experimentu.