The contribution of snow meltwater to catchment streamflow can be quantified through hydrograph separation analyses for which stable water isotopes (18O, 2H) are used as environmental tracers. For this, the spatial and temporal variability of the isotopic composition of meltwater needs to be captured by the sampling method. This study compares an optimized snowmelt lysimeter system and an unheated precipitation collector with focus on their ability to capture snowmelt rates and the isotopic composition of snowmelt. The snowmelt lysimeter system consists of three individual unenclosed lysimeters at ground level with a surface of 0.14 m2 each. The unheated precipitation collector consists of a 30 cm-long, extended funnel with its orifice at 2.3 m above ground. Daily snowmelt samples were collected with both systems during two snowfall-snowmelt periods in 2016. The snowmelt lysimeter system provided more accurate measurements of natural melt rates and allowed for capturing the small-scale variability of snowmelt process at the plot scale, such as lateral meltwater flow from the surrounding snowpack. Because of the restricted volume of the extended funnel, daily melt rates from the unheated precipitation collector were up to 43% smaller compared to the snowmelt lysimeter system. Overall, both snowmelt collection methods captured the general temporal evolution of the isotopic signature in snowmelt.
The paper outlines an epistemic logic based on the proof theory of substructural logics. The logic is a formal model of belief that i) is based on true assumptions (BTA belief) and ii) does not suffer from the usual omniscience properties., Článek nastiňuje epistemickou logiku založenou na důkazové teorii substrukturální logiky. Logika je formálním modelem víry, že i) je založena na pravdivých předpokladech (víra BTA) a ii) netrpí obvyklými vševědoucími vlastnostmi., and Igor Sedlár
During hydrological research in a Chilean swamp forest, we noted a pattern of higher streamflows close to midday and lower ones close to midnight, the opposite of an evapotranspiration (Et)-driven cycle. We analyzed this diurnal streamflow signal (DSS), which appeared mid-spring (in the growing season). The end of this DSS coincided with a sustained rain event in autumn, which deeply affected stream and meteorological variables. A survey along the stream revealed that the DSS maximum and minimum values appeared 6 and 4 hours earlier, respectively, at headwaters located in the mountain forests/ plantations than at the control point in the swamp forest. Et in the swamp forest was higher in the morning and in the late afternoon, but this process could not influence the groundwater stage. Trees in the mountain headwaters reached their maximum Ets in the early morning and/or close to midday. Our results suggest that the DSS is a wave that moves from forests high in the mountains towards lowland areas, where Et is decoupled from the DSS. This signal delay seems to convert the link between streamflow and Et in an apparent, but spurious positive relationship. It also highlights the role of landscape heterogeneity in shaping hydrological processes.
This paper deals with the problem of semantic analysis of contexts involving so-called anaphoric chain. The notion of anaphoric chain is explained by way of an example. Afterwards, a semantic analysis of sentences containing anaphora established in Transparent Intensional Logic (TIL) is examined. It is demonstrated that it is not adequate for texts including anaphoric chains. An alternative method using TIL that is capable to deal with all kinds of anaphora is proposed. Anyway, one may raise doubts as to whether both approaches are really analyses of anaphorically used expressions., Článek se zabývá problematikou sémantické analýzy kontextů zahrnujících tzv. Anaforický řetězec . Pojem anaforický řetězec je vysvětlen na příkladu. Následně je zkoumána sémantická analýza vět obsahujících anaforu vytvořených v transparentní intenzivní logice (TIL). Je prokázáno, že není vhodný pro texty obsahující anaforické řetězce. Navrhuje se alternativní metoda používající TIL, která je schopna se vypořádat se všemi druhy anafor. V každém případě lze pochybovat, zda jsou oba přístupy skutečně analýzou anaforicky používaných výrazů., and Miloš Kosterec
Several quite severe droughts occurred in Europe in the 21st century; three of them (2003, 2012 and 2015) hit also Slovakia. The Standardized Precipitation Index (SPI) and Standardized Precipitation and Evapotranspiration Index (SPEI) were used for assessment of meteorological drought occurrence. The research was established on discharge time series representing twelve river basins in Slovakia within the period 1981–2015. Sequent Peak Algorithm method based on fixed threshold, three parametric Weibull and generalized extreme values distribution GEV, factor and multiple regression analyses were employed to evaluate occurrence and parameters of hydrological drought in 2003, 2011–2012 and 2015, and the relationship among the water balance components. Results showed that drought parameters in evaluated river basins of Slovakia differed in respective years, most of the basins suffered more by 2003 and 2012 drought than by the 2015 one. Water balance components analysis for the entire period 1931–2016 showed that because of contin
We analyse water balance, hydrological response, runoff and snow cover characteristics in the Jalovecký Creek catchment (area 22 km2, mean elevation 1500 m a.s.l.), Slovakia, in hydrological years 1989–2018 to search for changes in hydrological cycle of a mountain catchment representing hydrology of the highest part of the Western Carpathians. Daily air temperature data from two meteorological stations located in the studied mountain range (the Tatra Mountains) at higher elevations show that the study period is 0.1°C to 2.4°C warmer than the climatic standard period 1951–1980. Precipitation and snow depth data from the same stations do not allow to conclude if the study period is wetter/drier or has a decreasing snow cover. Clear trends or abrupt changes in the analysed multivariate hydrometric data time series are not obvious and the oscillations found in catchment runoff are not coherent to those found in catchment precipitation and air temperature. Several time series (flashiness index, number of flow reversals, annual and seasonal discharge maxima, runoff coefficients) indicate that hydrological cycle is more dynamic in the last years of the study period and more precipitation runs off since 2014. The snow cover characteristics and climatic conditions during the snow accumulation and melting period do not indicate pronounced changes (except the number of days with snowfall at the Kasprowy Wierch station since 2011). However, some data series (e.g. flow characteristics in March and June, annual versus summer runoff coefficients since 2014) suggest the changes in the cold period of the year.
δ18O in precipitation at station Liptovský Mikuláš (about 8.5 km south from the outlet of the Jalovecký Creek catchment) remains constantly higher since 2014 that might be related to greater evaporation in the region of origin of the air masses bringing precipitation to the studied part of central Europe. Increased δ18O values are reflected also in the Jalovecký Creek catchment runoff. Seasonality of δ18O in the Jalovecký Creek became less pronounced since 2014. The most significant trends found in annual hydrological data series from the catchment in the study period 1989–2018 have the correlation coefficients 0.4 to 0.7. These trends are found in the number of flow reversals (change from increasing to decreasing discharge and vice versa), June low flow, number of simple runoff events in summer months (June to September) and the flashiness index. The attribution analysis suggests that drivers responsible for the changes in these data series include the number of periods with precipitation six and more days long, total precipitation amount in February to June, number of days with precipitation in June to September and total precipitation in May on days with daily totals 10 mm and more, respectively. The coefficients of determination show that linear regressions between the drivers and supposedly changed data series explain only about 31% to 36% of the variability. Most of the change points detected in the time series by the Wild Binary Segmentation method occur in the second and third decades of the study period. Both hydrometric and isotopic data indicate that hydrological cycle in the catchment after 2014 became different than before.
In this paper, we deal with sentences containing time references like ''five years ago'', ''three years older'', ''in five seconds''. It turns out that such sentences are pragmatically incomplete, because there is an elliptic reference to a calendar that makes it possible to determine the length of the time interval associated with a time duration like a year, month, day, or to compute the time interval denoted by terms like ''February 29, 2016''. Since Transparent Intensional Logic (TIL) takes into account two modal parameters, namely possible worlds of type ω and times of type τ, and this system is particularly apt for the analysis of natural language expressions, our background theory is TIL. Within this system, we define time intervals, calendar time durations, and last but not least a method for adding and multiplying time durations in a way that takes into account the leap days and leap seconds. As sample applications, we analyse two sentences, to wit, ''A year has 365 days'' and ''Adam is 5 years older than Bill''. and V tomto článku se zabýváme věty obsahujícími časové odkazy jako ''před pěti lety'', ''o tři roky starší'', ''za pět sekund''. Ukazuje se, že takové věty jsou pragmaticky neúplné, protože existuje eliptický odkaz na kalendář, který umožňuje určit délku časového intervalu spojeného s časovým obdobím jako rok, měsíc, den nebo vypočítat časový interval označované slovy ''29. února 2016''. Vzhledem k tomu, že Transparentní Intenzivní Logika (TIL) zohledňuje dva modální parametry, jmenovitě možné světy typu ω a časy typu τ, a tento systém je obzvláště vhodný pro analýzu přirozených jazykových výrazů, je naší teorií pozadí TIL. V rámci tohoto systému definujeme časové intervaly, trvání kalendáře, a v neposlední řadě metoda pro přidání a násobení doby trvání způsobem, který bere v úvahu skokové a skokové sekundy. Jako vzorové aplikace analyzujeme dvě věty s názvem ''rok má 365 dní'' a ''Adam je o 5 let starší než Bill''.
This paper proposes a non-trivial definition of the notion of analytic method. Working within the so-called instructional model of method, I distinguish three kinds of instructions which occur in methods: selective, executive, and declarative instructions. I discuss the relation between each of these and the analyticity of a method. Then I define the notions of an analytic use of an instruction and of an analytic instruction, which are at the basis of the proposed definition of an analytic method. Finally, I discuss the issue of circularity in the presented model which arises if we consider a finite agent testing a method for analyticity., Tato práce navrhuje netriviální definici pojmu analytická metoda. V rámci tzv. Instruktážního modelu metody rozlišuji tři druhy instrukcí, které se vyskytují v metodách: selektivní, exekutivní a deklarativní . Diskutuji o vztahu mezi každou z nich a analytičnosti metody. Dále definuji pojmy analytického použití instrukce a analytické instrukce , které jsou základem navrhované definice analytické metody. Závěrem se zabývám otázkou kruhovitosti v prezentovaném modelu, která vzniká, pokud uvažujeme konečný agent testující metodu analyticity., and Miloš Kosterec