Climate change impacts on water cycle at regional scale have been recently very investigated and discussed issue. This study focuses on changes of not only total runoff but also others water balance components: soil water content and evapotranspiration, in a monthly step. The climate change was described using outputs of two different global circulations models, ECHAM and HadCM based on two divergent scenarios (optimistic B1 and pessimistic A2) according to the IPCC. The simulation of water cycle was processed in the mesoscale Malse basin (437 km2 ) in southern Bohemia using distributed physically based hydrological model SWIM. The outputs for the time horizon 2050 were assessed in comparison with mean values from the representative period 1987-1998. The study indicates vulnerability against predicted changes of both temperature and precipitation patterns referred to the selected scenarios. A decrease of total runoff was expected; however, hydrological balance will be different particularly in the monthly pattern within a year. The aim of this article is to describe the impact on various hydrological balance components. and Stále aktuálnější otázkou jsou dnes dopady klimatické změny na hydrologický cyklus v regionálním měřítku. Tato studie se zaměřuje na sledování změny nejen odtoku, ale také změn obsahu půdní vody a evapotranspirace, a to v měsíčním kroku v průběhu roku. Pro popis změny klimatu byly zvoleny výstupy dvou globálních modelů ECHAM a HadCM podle dvou odlišných scénářů budoucího klimatického vývoje (optimistický B1 a pesimistický A2) podle IPCC. Hydrologický cyklus byl simulován použitím distribuovaného fyzikálního hydrologického modelu SWIM, a to na středně velkém povodí jihočeské Malše (437 km2 ), pro závěrový profil Pořešín. Výstupy odpovídající hypotetickému stavu v roce 2050 byly porovnávány s dlouhodobými průměrnými hodnotami z povodí za léta 1987-1998. Ukazuje se, že středně velké povodí Malše je citlivé vůči předpovídaným změnám teplot a srážek a podle scénářů dojde k očekávanému celkovému poklesu odtoku z povodí. Tento pokles bude provázen změnami hydrologické bilance během roku, viditelné především přesunem maximálních hodnot jednotlivých prvků do jiných měsíců.
Focusing on the idea that multivalent cations affect SOM matrix and surface, we treated peat and soil samples by solutions of NaCl, CaCl2 or AlCl3. Water binding was characterized with low field 1 H-NMR-relaxometry (20 MHz) and 1 H wideline NMR spectroscopy (400 MHz) and compared to contact angles. From 1 H wideline, we distinguished mobile water and water involved in water molecule bridges (WaMB). Large part of cation bridges (CaB) between SOM functional groups are associated with WaMB. Unexpectedly, 1 H NMRrelaxometry relaxation rates suggest that cross-linking in the Al-containing peat is not stronger than that by Ca. The relation between percentage of mobile water and WaMB water in the context of wettability and 1 H NMR relaxation times confirms that wettability controls the water film surrounding soil particles. Wettability is controlled by WaMB-CaB associations fixing hydrophilic functional groups in the SOM interior. This can lead to severe water repellency. Wettability decreases with increasing involvement of functional groups in CaB-WaMB associations. The results demonstrate the relevance of CaB and WaMB for the dynamics of biogeochemical and hydrological processes under field conditions, as only a few percent of organic matter can affect the physical, chemical, and biological functioning of the entire 3-phase ecosystem.
People partaking in a conversation can add to the common ground of said conversation by performing different speech acts. That is, they can influence which propositions are presumed to be shared among them. In this paper, I am going to apply the common ground framework to the phenomenon of epistemic injustice. In doing so, I am going to focus on two kinds of speech acts: making assertions and asking certain kinds of questions. And I am going to look at three varieties of epistemic injustice: testimonial injustice, inquiring injus- tice and interpretative injustice. I am going to argue that what all these varieties of epistemic injustice have in common is that they unfairly inhibit the speaker’s ability to add to the common ground in the way intended by her. This in turn negatively affects which conversational roles a speaker can play in a given conversation. Based on these results, I am going to end by looking at some of the harms that epistemic injustice inflicts upon its victims.
Long-term water uptake of Douglas-fir and Norway spruce trees, growing in condition of Moravian upland, was studied with aim of comparing sap flow in small roots with flow in stems. Sap flow was measured by the heat field deformation method using multi-point sensors for stems and single-point sensors for roots. Differences between species were found in relationships between sap flow in tree stems and water uptake by roots, suggesting that Douglas-fir is able to take water from deeper soil more efficiently than spruce. This allows Douglas-fir to transpire more water especially during drought and grow faster than spruce. These biological features should be taken into account for future forest species compositions because they may have impact on both, forestry and hydrology.
Groundwater and surface water interaction play an important role for groundwater recharge, drought management and water quality issues. Based on a case study in Lower Austria different techniques for estimation of riverbed infiltration were applied. The aim was to assess the impact of upstream release flow directions for the downstream sections. Due to the fact of large streambed conductivities, infiltration losses considerably contribute to the water balance of the system. The applied methods dealt with empirical infiltration formulas based on sediment particle size distribution, soil physical analysis, difference discharge measurements along river branches and point measurements of infiltration by means of double ring infiltrometer and riverbed lysimeter. Awaring the fact that the infiltration processes vary in space and time the gained results formed a basis for definition of potential values of infiltration. It could be concluded, that for the investigated environment the different methods exhibited comparable results with the exception of the empirical formulas, which tend to significantly overestimate the average values. and Vzájemná interakce povrchové a podzemní vody je velmi důležitá pro hodnocení zdrojů podzemních vod, hospodaření s vodou a její kvalitu. Na základě zkušeností s řešením projektu v Dolním Rakousku byly použity pro odhad infiltrace říčním korytem dále uvedené metody. Cílem řešení bylo mimo jiné stanovit vliv průtoku a směru pohybu vody v horní části toku na profily v spodní části toku. Vzhledem k vysoké hydraulické vodivosti dna toku se ztráty infiltrací výrazně podílejí na vodní bilanci systému. Pro odhad infiltrace byly použity jednak empirické rovnice (na základě granulometrického složení), fyzikální rozbory půdních vzorků, terénní lysimetrická měření ve dně toku a ''bodová'' měření dvouválcovou metodou. Uvážíme-li, že infiltrace je časově a prostorově proměnná, dosažené výsledky jsou základem pro určení potenciální hodnoty infiltrace. Závěrem je možno konstatovat, že v daných podmínkách použité metody poskytly srovnatelné výsledky, s výjimkou empirických rovnic, jejichž výsledky byly systematicky řádově vyšší.
In this study Active Learning Method (ALM) as a novel fuzzy modeling approach is compared with optimized Support Vector Machine (SVM) using simple Genetic Algorithm (GA), as a well known datadriven model for long term simulation of daily streamflow in Karoon River. The daily discharge data from 1991 to 1996 and from 1996 to 1999 were utilized for training and testing of the models, respectively. Values of the Nash-Sutcliffe, Bias, R2 , MPAE and PTVE of ALM model with 16 fuzzy rules were 0.81, 5.5 m3 s -1, 0.81, 12.9%, and 1.9%, respectively. Following the same order of parameters, these criteria for optimized SVM model were 0.8, -10.7 m3 s-1, 0.81, 7.3%, and -3.6%, respectively. The results show appropriate and acceptable simulation by ALM and optimized SVM. Optimized SVM is a well-known method for runoff simulation and its capabilities have been demonstrated. Therefore, the similarity between ALM and optimized SVM results imply the ability of ALM for runoff modeling. In addition, ALM training is easier and more straightforward than the training of many other data driven models such as optimized SVM and it is able to identify and rank the effective input variables for the runoff modeling. According to the results of ALM simulation and its abilities and properties, it has merit to be introduced as a new modeling method for the runoff modeling. and Cieľom štúdie bolo porovnať možnosti dlhodobej simulácie denných prietokov v rieke Karoon pomocou novovyvinutej fuzzy metódy aktívneho učenia (Active Learning Method - ALM) a známej metódy vektormi podporených strojov (Support Vector Machine - SVM), optimalizovanej genetickým algoritmom (GA). Na tréning a testovanie modelov boli použité časové rady denných prietokov za obdobie rokov 1991 až 1996 a 1996 až 1999. Hodnoty parametrov Nash-Sutcliffe, Bias, R2 , MPAE a PTVE pre model ALM boli 0,81; 5,5 m3 s-1; 0,81; 12,9% a 1,9%. Parametre v tom istom poradí pre model SVM boli 0,8 -10,7 m3 s-1, 0,81; 7,3%; a -3,6%. Z výsledkov simulácií vyplýva, že aplikáciou metód ALM a SVM možno získať porovnateľné a akceptovateľné výsledky. Podobnosť výsledkov medzi ALM a SVM implikuje vhodnosť novovyvinutej metódy ALM pre simuláciu odtoku. Tréning ALM je ľahší a jednoduchší ako je tréning ďalších dátami riadených modelov podobného typu. Navyše algoritmus ALM je schopný identifikovať a zoradiť efektívne vstupné premenné pre modelovanie odtoku. Na základe dosiahnutých výsledkov možno metódu ALM zaradiť medzi nové, alternatívne metódy modelovania odtoku.
Estimation of discharge from ungauged catchments based on rainfall-runoff analysis is a very frequent task in engineering hydrology. Very often, design discharges are needed for streams or small rivers where no streamflow data is available (river training works, culverts, small hydropower plants, etc). This study uses a well established lumped hydrologic rainfall-runoff model to compare two different approaches in data preparation. The traditional method of manual obtainment of catchment parameters was compared to a more contemporary methodology using automation with geographic information systems, digital terrain models and available datasets, with an emphasis on open-source tools and freely available datasets. Both techniques were implemented on more than 100 catchments in Serbia to calculate storm runoff response. The results show minor differences that are insignificant compared to the time and resources saved with the automated techniques. The use of such automated methods enables the hydrologist to direct more attention to other factors that influence discharge even more than catchment parameters, such as rainfall, soil and land use data.
Paper presents comparison of the daily reference crop (grass vegetation cover) potential evapotranspiration results calculated by the two modifications of the Penman-Monteith type equation. The first modification was published in FAO recommendation (Allen at al., 1998), PM-FAO, the second is modification according to Budagovskiy (1964) and Novák (1995), PM-BN. Both are used in soil water simulation models HYDRUS-1D and GLOBAL. Calculations were performed for frost-free seasons of the years 2000-2009, using the meteorological station Gabčíkovo (South Slovakia) meteorological data and canopy characteristics. The results indicate significant differences in daily and seasonal potential evapotranspiration. Reasons for those differences are discussed; they should be in different net radiation and aerodynamic resistance estimation methods.
The paper summarises the results of the first year of the project GACR No. 205/99/1426 focused on the comparison of the pollutant concentration in the fog (low cloud ) water of two industrial regions of the Czech Republic with different atmospheric load. During the first project year the samples of the fog (cloud) water were collected and analysed. The number of samples, collected at the mountain observatories Milesovka (Mileschauer) and at Churanov, permitted the first preliminary comparison of the regions. The subject of comparison were the mean values of the pollutant concentration, the concentration of pollutants in dependence on the wind direction and in the dependence on the sector from which the air particles (and consequently also the pollutants) were transported to the considered stand. and Příspěvek shrnuje výsledky 1. roku řešení projektu GA CR 205/99/1426, který je věnován porovnání koncentrací polutantu v mlžné (oblačné) vode průmyslově odlišně zatížených oblastí ČR. V průběhu 1. roku řešení projektu byly odebrány a chemicky analyzovány vzorky mlžné (oblačné) vody. Počet odebraných a analyzovaných vzorků z horské observatoře ÚFA Milešovka a horského pracovište ÚH Churáňov umožnil první porovnání oblastí. Porovnávány byly průměrné hodnoty koncentrací polutantů, koncentrace polutantů v závislosti na směru větru a v závislosti na sektoru, ze kterého jsou vzduchové částice (tedy i polutanty) na dané
stanovište transportovány.
Although the quantification of real evapotranspiration (ETr) is a prerequisite for an appropriate estimation of the water balance, precision and uncertainty of such a quantification are often unknown. In our study, we tested a combined growth and soil water balance model for analysing the temporal dynamics of ETr. Simulated ETr, soil water storage and drainage rates were compared with those measured by 8 grass-covered weighable lysimeters for a 3-year period (January 1, 1996 to December 31, 1998). For the simulations, a soil water balance model based on the Darcy-equation and a physiological-based growth model for grass cover for the calculation of root water uptake were used. Four lysimeters represented undisturbed sandy soil monoliths and the other four were undisturbed silty-clay soil monoliths. The simulated ETr-rates underestimated the higher ETr-rates observed in the summer periods. For some periods in early and late summer, the results were indicative for oasis effects with lysimeter-measured ETr-rates higher than corresponding calculated rates of potential grass reference evapotranspiration. Despite discrepancies between simulated and observed lysimeter drainage, the simulation quality for ETr and soil water storage was sufficient in terms of the Nash-Sutcliffe index, the modelling efficiency index, and the root mean squared error. The use of a physiological-based growth model improved the ETr estimations significantly.