Spatial and temporal variability of snow line (SL) elevation, snow cover area (SCA) and depletion (SCD) in winters 2001-2014 is investigated in ten main Slovak river basins (the Western Carpathians). Daily satellite snow cover maps from MODIS Terra (MOD10A1, V005) and Aqua (MYD10A1, V005) with resolution 500 m are used. The results indicate three groups of basins with similar variability in the SL elevation. The first includes basins with maximum elevations above 1500 m a.s.l. (Poprad, Upper Váh, Hron, Hornád). Winter median SL is equal or close to minimum basin elevation in snow rich winters in these basins. Even in snow poor winters is SL close to the basin mean. Second group consists of mid-altitude basins with maximum elevation around 1000 m a.s.l. (Slaná, Ipeľ, Nitra, Bodrog). Median SL varies between 150 and 550 m a.s.l. in January and February, which represents approximately 40–80% snow coverage. Median SL is near the maximum basin elevation during the snow poor winters. This means that basins are in such winters snow free approximately 50% of days in January and February. The third group includes the Rudava/Myjava and Lower Váh/Danube. These basins have their maximum altitude less than 700 m a.s.l. and only a small part of these basins is covered with snow even during the snow rich winters. The evaluation of SCA shows that snow cover typically starts in December and last to February. In the highest basins (Poprad, Upper Váh), the snow season sometimes tends to start earlier (November) and lasts to March/April. The median of SCA is, however, less than 10% in these months. The median SCA of entire winter season is above 70% in the highest basins (Poprad, Upper Váh, Hron), ranges between 30-60% in the mid-altitude basins (Hornád, Slaná, Ipeľ, Nitra, Bodrog) and is less than 1% in the Myjava/Rudava and Lower Váh/Danube basins. However, there is a considerable variability in seasonal coverage between the years. Our results indicate that there is no significant trend in mean SCA in the period 2001-2014, but periods with larger and smaller SCA exist. Winters in the period 2002-2006 have noticeably larger mean SCA than those in the period 2007-2012. Snow depletion curves (SDC) do not have a simple evolution in most winters. The snowmelt tends to start between early February and the end of March. The snowmelt lasts between 8 and 15 days on average in lowland and high mountain basins, respectively. Interestingly, the variability in SDC between the winters is much larger than between the basins.
Mixed evergreen-deciduous broadleaved forest is the transitional type of evergreen broadleaved forest and deciduous broadleaved forest, and plays a unique eco-hydrologic role in terrestrial ecosystem. We investigated the spatiotemporal patterns of throughfall volume of the forest type in Shennongjia, central China. The results indicated that throughfall represented 84.8% of gross rainfall in the forest. The mean CV (coefficient of variation) of throughfall was 27.27%. Inter-event variability in stand-scale throughfall generation can be substantially altered due to changes in rainfall characteristics, throughfall CV decreased with increasing rainfall amount and intensity, and reached a quasi-constant level when rainfall amount reached 25 mm or rainfall intensity reached 2 mm h–1. During the leafed period, the spatial pattern of throughfall was highly temporal stable, which may result in spatial heterogeneity of soil moisture.
An experimental investigations on the effect of convergence of stream lines on the Darcy and non-Darcy parameters for different radial lines for different ratios of the radii was studied in a convergent flow permeameter. The applicability of a resistance law relating friction factor and Reynolds number using the square root of intrinsic permeability as the characteristic length is examined for flow with converging boundaries. In this study, crushed rock of size 3.25 mm and 4.73 mm were used as media and water as fluid, to develop curves relating friction factor and Reynolds number for different radial lines with different ratios of the radii. and V konvergentnom permeametri sme experimentálne skúmali vplyv konvergencie prúdnic na Darcyovské a nedarcyovské charakteristiky prúdenia. Pre prúdenie v pórovitom prostredí s konvergujúcimi hranicami sme zisťovali použiteľnosť zákona odporu, ktorý dáva do súvislosti súčiniteľ trenia a Reynoldsovo číslo, používajúc druhú odmocninu vnútornej priepustnosti ako charakteristickú dĺžku. Pre získanie kriviek závislostí medzi súčiniteľom trenia a Reynoldsovým číslom pre rôzne hydraulické polomery a rôzne pomery hydraulických polomerov sme použili drvenú horninu s veľkosťou zŕn 3,25 mm a 4,73 mm, tekutinou bola voda.
Efekt rádiofrekvenčnej ablácie predsieňovokomorového spojenia môže byť sprevádzaný nežiadúcim vplyvom pravokomorovej stimulácie. Cieľom práce bolo zhodnotiť včasné hemodynamické dôsledky katétrovej ablácie u pacientov s trvalou fibriláciou predsiení rezistentnou na medikamentóznu liečbu. Metóda: Do štúdie sme zahrnuli 19 pacientov s priemerným vekom 66,9 ? 12,4 roka. V závislosti na bazálnej ejekčnej frakcii (EF) sme pacientov rozdelili do dvoch skupín (I. skupina pacientov s EF menej ako 50 %, II. skupina s EF 50 % a viac). Pacienti sa podrobili rádiofrekvečnej ablácii predsieňovokomorového spojenia a implantácii kardiostimulátora. Hemodynamické zmeny sme hodnotili pomocou stanovenia vývrhového (VO) a minútového objemu (MO) echokardiografickým spôsobom bazálne pred zákrokom a po zákroku pri rôznych frekvenciach stimulácie. Na presnejšie zhodnotenie stavu pacientov sme vytvorili indexy VOi a MOi ako pomer týchto veličín pri rôznych frekvenciach stimulácie voči ich bazálnej hodnote. Výsledky: U pacientov s nízkou EF stúpa VO pri všetkých frekvenciach stimulácie, pričom maximum účinku možno badať vo frekvenčnom pásme 60?100/min. Pri frekvencii stimulácie 60/min stúpol z 26,4 ml pred abláciou na 39,5 ml po ablácii. MO stúpa alebo sa nemení pri všetkých frekvenciach okrem frekvencie 60/min, pri ktorej zvýšenie VO nestačí kompenzovať pokles MO v dôsledku výrazného poklesu frekvencie. Pacienti v II. skupine mali pred abláciou vysokú hodnotu VO (52,3 ml). Po zákroku stúpol VO len pri frekvencii stimulácie 60 a 80/min (64,0 a 55,1 ml). Rovnako mali títo pacienti pred abláciou vysoký aj MO (6 097 ml). Po výkone MO poklesol pri všetkých frekvenciach stimulácie, ale vykazoval stúpajúcu tendenciu. Štatistickým vyhodnotením sme zistili negatívnu koreláciu medzi VOi a MOi na jednej strane a EF a priemerom ľavej komory v systole na druhej strane. Záver: Naše výsledky ukazujú, že rádiofrekvenčná katétrová ablácia atrioventrikulárneho uzla (RFCA AVN) je prínosom vo vybraných prípadoch pacientov v oboch skupinách, i keď mechanizmus zlepšenia klinického stavu je odlišný., Silvia Mišíková, Branislav Stančák, E. Komanová, and Lit. 33
Cieľ: V práci sme sa zamerali na vedomosti pacientov s astmou v oblastiach self-manažmentu tohto ochorenia a najmä na vplyv faktoru dĺžky trvania tohto ochorenia na úroveň vedomostí o self-manažmente. Zároveň sme zisťovali vzťah medzi úrovňou vedomostí o self-manažmente ochorenia a kontrolou astmy. Metodika: V tejto prierezovej štúdii bolo do súboru zaradených 297 respondentov. Na testovanie kontroly astmy a úrovne vedomostí pacientov sme použili valídne nástroje a to Dotazník vedomostí o self-manažmente astmy pre dospelých (Measuring asthma self-management knowledge in adults) a Test kontroly astmy (Astma Control Test ACTTM). Na štatistické spracovanie dát boli využité: Pearsonov Chi-kvadrat test nezávislosti a Spearmanov korelačný koeficient. Výsledky: Až 220 z 297 respondentov (74,07 %) preukázalo nedostatočné vedomosti, a to konkrétne v doméne Vedomosti o liečbe astmy. V oblasti Manažment bronchiálnej astmy malo nedostatočné vedomosti 191 respondentov (64,31 %). Početnosť správnych odpovedí zároveň naznačuje, že úroveň vedomostí v doménach self-manažmentu astmy, významných pre kontrolu ochorenia, bola vyššia v skupine pacientov diagnostikovaných v priemere jeden rok ako v skupine, ktorá trpí ochorením dlhšie (6-10 rokov), i keď rozdiel nie je štatisticky významný. Záver: Nedostatky vo vedomostiach astmatikov, vyššia frekvencia chýb v oblastiach self-manažmentu, vrátane self-monitoringu a horšia kontrola astmy pri ochorení diagnostikovanom viac ako 6 rokov naznačujú, že je potrebné v klinickej praxi venovať čas a pozornosť reedukácii, opakovanému posúdeniu vedomostí a praktických zručností (aplikácia metód self-manažmentu, inhalačnej techniky) v skupine už skôr diagnostikovaných astmatikov., Aim: This project is aimed to find out the patient knowledge with asthma in the area of self-management of this disease and particularly the influence of the length of the disease on the knowledge level about self-management. At the same time we tried to find out the relation between the knowledge level of the asthma self-management and control of asthma disease. Methods: The total number of 297 adult asthma patients were included in the cross sectional study. The valid instruments Asthma Control Test and Measuring asthma self management knowledge in adults were used for testing asthma control and the degree of patient knowledge in self management of asthma. The Chi-squared test and the Spearman´s rank correlation coefficient were used for statistical processing of data. Results: A total of 220 out of 279 respondents (74%) showed poor knowledge of selfmanagement of asthma, particularly in “Knowledge of asthma treatment” domain and 191 patients in “Management of bronchial asthma” domain (64%). Patients who had been diagnosed one year ago had better level of knowledge in selfmanagement of asthma than those who had been treated for asthma longer than six years (6-10 years). This difference was not significant, but it was related to those domains which has significant influence on asthma control (domains 2-5). Conclusion: Poor knowledge of asthma patients, higher frequency of errors in self management and worse control of asthma in patients with asthma longer than six years imply the need for better and repeated education, check of patient knowledge and skills for self-management, use of peak flow meter included in this group of patients., Michaela Dingová, Petronela Osacká, and Literatura
Recent studies have shown that the presence of ice cover leads to an intensified local scour pattern in the vicinity of bridge piers. To investigate the local scour pattern in the vicinity of bridge pier under ice-covered flow condition comparing to that under open channel flow condition, it is essential to examine flow field around bridge piers under different flow conditions. In order to do so, after creation of smooth and rough ice covers, three-dimensional timeaveraged velocity components around four pairs of bridge piers were measured using an Acoustic Doppler velocimetry (ADV). The ADV measured velocity profiles describe the difference between the velocity distributions in the vicinity of bridge piers under different covered conditions. Experimental results show that the vertical velocity distribution which represents the strength of downfall velocity is the greatest under rough covered condition which leads to a greater scour depth. Besides, results show that the turbulent intensity increases with pier size regardless of flow cover, which implies that larger scour depth occurs around piers with larger diameter.
The need for a better understanding of factors controlling the variability of soil water content (θ) in space and time to adequately predict the movement of water in the soil and in the interphase soil-atmosphere is widely recognised. In this paper, we analyse how soil properties, surface cover and topography influence soil moisture (θ) over karstic lithology in a sub-humid Mediterranean mountain environment. For this analysis we have used 17 months of θ measurements with a high temporal resolution from different positions on a hillslope at the main recharge area of the Campo de Dalías aquifer, in Sierra de Gádor (Almería, SE Spain). Soil properties and surface cover vary depending on the position at the hillslope, and this variability has an important effect on θ. The higher clay content towards the lower position of the hillslope explains the increase of θ downslope at the subsurface horizon throughout the entire period studied. In the surface horizon (0-0.1 m), θ patterns coincide with those found at the subsurface horizon (0.1-0.35 m) during dry periods when the main control is also exerted by the higher percentage of clay that increases downslope and limits water depletion through evaporation. However, in wet periods, the wettest regime is found in the surface horizon at the upper position of the hillslope where plant cover, soil organic matter content, available water, unsaturated hydraulic conductivity (Kunsat) and infiltration rates are higher than in the lower positions. The presence of rock outcrops upslope the θ sampling area, acts as runoff sources, and subsurface flow generation between surface and subsurface horizons also may increase the differences between the upper and the lower positions of the hillslope during wet periods. Both rock and soil cracks and fissures act disconnecting surface water fluxes and reducing run-on to the lower position of the hillslope and thus they affect θ pattern as well as groundwater recharge. Understanding how terrain attributes, ground cover and soil factors interact for controlling θ pattern on karst hillslope is crucial to understand water fluxes in the vadose zone and dominant percolation mechanisms which also contribute to estimate groundwater recharge rates. Therefore, understanding of soil moisture dynamics provides very valuable information for designing rational strategies for the use and management of water resources, which is especially urgent in regions where groundwater supports human consume or key economic activities.
Intense collisional transport of bimodal sediment mixture in open-channel turbulent flow with water as carrying liquid is studied. The study focusses on steep inclined flows transporting solids of spherical shape and differing in either size or mass. A process of vertical sorting (segregation) of the two different solids fractions during the transport is analyzed and modelled. A segregation model is presented which is based on the kinetic theory of granular flows and builds on the Larcher-Jenkins segregation model for dry bimodal mixtures. Main modifications of the original model are the carrying medium (water instead of air) and a presence of a non-uniform distribution of sediment across the flow depth. Testing of the modified model reveals that the model is applicable to flow inclination slopes from 20 to 30 degrees approximately, making it appropriate for debris flow conditions. Changing the slope outside the specified range leads to numerical instability of the solution. A use of the bimodal mixture model is restricted to the grain size ratio 1.4 and no restriction is found for the grain mass ratio in a realistic range applicable to natural conditions. The model reveals trends in the vertical sorting under variable conditions showing that the sorting is more intense if flow is steeper and/or the difference in size or mass is bigger between the two sediment fractions in a bimodal mixture.