In many Austrian catchments in recent decades an increase in the mean annual air temperature and precipitation has been observed, but only a small change in the mean annual runoff. The main objective of this paper is (1) to analyze alterations in the performance of a conceptual hydrological model when applied in changing climate conditions and (2) to assess the factors and model parameters that control these changes. A conceptual rainfall-runoff model (the TUW model) was calibrated and validated in 213 Austrian basins from 1981–2010. The changes in the runoff model’s efficiency have been compared with changes in the mean annual precipitation and air temperature and stratified for basins with dominant snowmelt and soil moisture processes. The results indicate that while the model’s efficiency in the calibration period has not changed over the decades, the values of the model’s parameters and hence the model’s performance (i.e., the volume error and the runoff model’s efficiency) in the validation period have changed. The changes in the model’s performance are greater in basins with a dominant soil moisture regime. For these basins, the average volume error which was not used in calibration has increased from 0% (in the calibration periods 1981–1990 or 2001–2010) to 9% (validation period 2001–2010) or –8% (validation period 1981–1990), respectively. In the snow-dominated basins, the model tends to slightly underestimate runoff volumes during its calibration (average volume error = –4%), but the changes in the validation periods are very small (i.e., the changes in the volume error are typically less than 1–2%). The model calibrated in a colder decade (e.g., 1981–1990) tends to overestimate the runoff in a warmer and wetter decade (e.g., 2001–2010), particularly in flatland basins. The opposite case (i.e., the use of parameters calibrated in a warmer decade for a colder, drier decade) indicates a tendency to underestimate runoff. A multidimensional analysis by regression trees showed that the change in the simulated runoff volume is clearly related to the change in precipitation, but the relationship is not linear in flatland basins. The main controlling factor of changes in simulated runoff volumes is the magnitude of the change in precipitation for both groups of basins. For basins with a dominant snowmelt runoff regime, the controlling factors are also the wetness of the basins and the mean annual precipitation. For basins with a soil moisture regime, landcover (forest) plays an important role.
Inspired by the work of Sellars, Cumpa (2014, 2018) and Buonomo (2021) have argued that we can evaluate our metaphysical proposals on fundamental categories in terms of their capacity for reconciling the scientific and the manifest image of the world. This criterion of fundamentality would allow us to settle the question of which categories among those proposed in the debate—e.g., substance, structure or facts—have a better explanatory value. The aim of this essay is to argue against a central assumption of the criterion: semantic descriptivism. Specifically, I aim at showing that the criterion rests on the idea that the manifest picture is mostly a description of the world, and thus, it commits us with certain realism. Instead, I argue that at least some of the vocabulary we use to construct our manifest picture of the world, mental vocabulary, is evaluative rather than descriptive and thus creates problems in reconciling the manifest picture with scientific psychology and neurosciences. I conclude with some remarks on alternatives that could provide a way out of the fundamentality criterion.
Suspended sediment dynamics during hydrological events influenced by rainstorms and factors controlling changes in sediment dynamics were investigated in a small basin scale, since small basins can be considered as one of the most important sediment sources. The study focuses on the agricultural microbasin Rybárik, near Považská Bystrica (Western Slovakia). Suspended sediment concentrations were measured during discharge waves in the years 1987-1990, 1992, 2000 and 2001. The behaviour of suspended sediments in watercourses is not only a function of energy conditions, but also a function of sediment availability. The variations in sediment supply and sediment depletion result in so-called hysteresis effects. Thus, suspended sediment concentrations at rising and falling limbs are different for equal discharges. Positive and anti-clockwise hysteresis was observed at Rybárik basin. The procedure of separation of factors controlling sediment dynamics has given more realistic view on production and transport of suspended sediments. It is confirmed that spatial and temporal variability of sediment availability and suspended sediment dilution by the baseflow, mainly in the case of two or more waves following one after another control significantly suspended sediment dynamics. and Keďže malé povodia možno považovať za jeden z hlavných zdrojov sedimentov, na malom povodí bol skúmaný režim plavenín počas hydrologických udalostí spôsobených prívalovými zrážkami, a faktory ovplyvňujúce zmeny v dynamike plavenín. Štúdia bola vykonaná na poľnohospodárskom mikropovodí Rybárik pri Považskej Bystrici. Koncentrácie plavenín boli merané počas prietokových vĺn v rokoch 1987- 1990, 1992, 2000 a 2001. Režim plavenín vo vodných tokoch nie je funkciou len transportnej kapacity toku, ale aj dostupnosti sedimentov. Zmeny v zásobovaní a vyčerpávaní sedimentov spôsobujú tzv. hysterézny efekt. To znamená, že koncentrácie plavenín na stúpajúcej a klesajúcej vetve vlny sú rozdielne pri tých istých prietokoch. V povodí Rybárik bola pozorovaná pozitívna aj opačná hysteréza. Postup izolovania faktorov, ktoré ovplyvňujú dynamiku plavenín, prináša reálnejší obraz o tvorbe a transporte plavenín. Ukazuje sa, že zrieďovanie koncentrácií plavenín základným odtokom a časová a priestorová heterogenita územia z hľadiska dostupnosti sedimentov, predovšetkým v situácii tesne za sebou nasledujúcich prívalových vĺn, sa významne podieľajú na celkovej dynamike plavenín.
I explain how Karl Popper resolved the problem of induction but not the pragmatic problem of induction. I show that Popper's proposed solution to the pragmatic problem of induction is inconsistent with his solution to the problem of induction. I explain how Popper’s falsificationist epistemology can solve the pragmatic problem of induction in the same negative way that it solves the problem of induction.