The extreme rainfall events in Central and East Europe on August 2002 rise the question, how other basins would respond on such rainfall situations. Such theorisation helps us to arrange in advance the necessary activity in the basin to reduce the consequence of the assumed disaster. The aim of the study is to recognise a reaction of the Uh River basin (Slovakia, Ukraine) to the simulated catastrophic rainfall events from August 2002. Two precipitation scenarios, sc1 and sc2, were created. The first of them was based on August’s precipitation from Ybbs (Austria), the second one was based on precipitation from south Bohemia. The rainfall-runoff model HBV-light was used to simulate average daily discharge. Observed daily precipitation in each August during the period 1990-1999 was replaced by these two scenarios and the daily discharges were simulated in Lekárovce gauging station. Peak discharges were computed from the daily averages according to the empirical relationship. In last step, a selection of the best theoretical distribution function of the annual maximum discharge was done using Qmax data series from the period 1931-2001. and Extrémne zrážkové udalosti z augusta 2002 v strednej a východnej Európe vyvolali otázku, ako by na podobné zrážkové situácie reagovali iné povodia. Takéto teoretické simulácie poskytujú možnosť eliminovať dôsledky extrémnych hydrologických situácií. Cieľom tejto štúdie je poznať reakciu povodia rieky Uh (Slovensko, Ukrajina) na prípadnú katastrofickú zrážkovo-odtokovú situáciu, aká bola v auguste 2002. Pre simuláciu extrémnych zrážkovo-odtokových situácií boli vytvorené dva katastrofické scenáre sc1 a sc2. Prvý scenár bol určený na základe zrážkových úhrnov nameraných v Rakúska (Ybbs) a druhý na základe zrážkových úhrnov nameraných v južných Čechách počas augusta 2002. Na simuláciu priemerných denných prietokov bol použitý model HBV-light. Merané denné zrážky v každom mesiaci august počas obdobia 1990-1999 boli zmenené podľa týchto scenárov. Následne boli simulované priemerné denné prietoky v stanici Uh-Lekárovce modelom HBV-light. Vrcholové prietoky boli počítané z denných priemerov vzhľadom na odvodené empirické vzťahy. V poslednom kroku štúdie bola vybratá najvhodnejšia teoretická distribučná funkcia maximálnych ročných prietokov použitím ročných Qmax z obdobia 1931-2001.
The aim of this study was to assess the impact of different vegetation on the distribution of rainfall (due to throughfall and stemflow), water regime, and Al and SO4 2- leaching from forest soils. The water flow and Al and SO4 2- transport were modeled using HYDRUS-1D. The study was performed at two elevation transects on the Paličník and Smědava Mountain in Jizera mountains. Podzols and Cambisols were prevailing soil units in this area. It was shown that the effect of the precipitation redistribution on water regime was considerable in the beech forest, while it was almost negligible in the spruce forest. Redistribution of precipitation under trees caused runoff (in one case), increased water discharge through the soil profile bottom, reduction of water storage in the soil, and thus reduction of root water uptake. Simulated Al leaching from the soil profile was determined mainly by the initial Al content in the soil profile bottom. Leaching of SO4 2- was mainly determined by its initial content in the soil and to a lesser extent by redistributed precipitation and SO4 2- deposition.
This study is focused on the snowmelt runoff simulations for the upper Hron basin using dte degree-day approach of the SRM model. Our effort was directed at the determination and selection of input data and model parameters using GIS tools. The aim of this paper was to simulate the snowmelt runoff using only regularly measured data, without their special pre-processing. Comparison between measured and computed runoff indicates that the SRM model could be used for the snowmelt runoff simulation for the upper Hron basin. Results for the smaller upper Telgart subbasin were not so acceptable, because of lack of representative input data, which is essential for the determination of the snow depletion curve. and Práca je venovaná simulácii odtoku zo snehu pre povodie horného Hrona s využitím modelu odtoku zo snehu - SRM. Hlavným cieľom práce bolo posúdiť a otestovať možnosti výberu a určenia vstupných údajov a kalibrácie parametrov do modelu SRM s využitím dát pravidelne meraných v sieti meteorologických staníc. Z výsledkov vyplýva, že SRM veľmi dobre simuluje prietok pre povodie horného Hrona ako celku. Simulácia pre povodie horného Hrona rozdeleného na dve výškové zóny, a najmä pre čiastkové povodie Hrona po Telgárt, nedosiahla akceptovateľné výsledky. Tento fakt spôsobili najmä nedostatečné vstupné údaje. Kritickým sa ukázali najmä vstupné informácie o priestorovom rozložení snehovej pokrývky.
This study focuses on the quantification of non-isothermal soil moisture transport and evaporation fluxes in vegetated area. A one-dimensional numerical model is developed by integrating a multi-phase flow model with a twolayer energy-balance model. The non-isothermal multi-phase flow model solves four governing equations for coupled air, vapour, moisture, and heat transport in soil porous medium. The two-layer energy balance model estimates evaporation fluxes from transpiration, interception, and soil surface. The model was implemented to an oak forest area in Missouri, USA. For model calibration and validation, measurements of energy fluxes, soil moisture, and soil temperature were used. The proposed model is compared with a simple model that couples the Penman-Monteith equation with the Richards’ equation. The results indicate that the simple model underestimate the total evaporation rate. On the contrary, the proposed model includes a more detailed description of energy transfer, which could improve the accuracy in estimating evaporation rates. The proposed model could be a promising tool to quantify the energy and moisture fluxes in a soil-vegetation-atmosphere continuum in vegetated area.
The paper presents an evaluation of the combined use of the HYDRUS and SWI2 packages for MODFLOW as a potential tool for modeling recharge in coastal aquifers subject to saltwater intrusion. The HYDRUS package for MODFLOW solves numerically the one-dimensional form of the Richards equation describing water flow in variablysaturated media. The code computes groundwater recharge to or capillary rise from the groundwater table while considering weather, vegetation, and soil hydraulic property data. The SWI2 package represents in a simplified way variable-density flow associated with saltwater intrusion in coastal aquifers. Combining these two packages within the MODFLOW framework provides a more accurate description of vadose zone processes in subsurface systems with shallow aquifers, which strongly depend upon infiltration. The two packages were applied to a two-dimensional problem of recharge of a freshwater lens in a sandy peninsula, which is a typical geomorphologic form along the Baltic and the North Sea coasts, among other places. Results highlighted the sensitivity of calculated recharge rates to the temporal resolution of weather data. Using daily values of precipitation and potential evapotranspiration produced average recharge rates more than 20% larger than those obtained with weekly or monthly averaged weather data, leading to different trends in the evolution of freshwater-saltwater interfaces. Root water uptake significantly influenced both the recharge rate and the position of the freshwater-saltwater interface. The results were less sensitive to changes in soil hydraulic parameters, which in our study were found to affect average yearly recharge rates by up to 13%.
In agricultural land use, organic residues such as compost, digestate, and sewage sludge are discussed as costeffective soil conditioner that may improve the water holding capacity and crop available soil moisture. The objective of this study is to determine the effect of application of digestates with different compositions in maize, sugar beet and winter wheat, compost of shrub debris and sewage sludge on shrinkage behaviour and contact angle of till-derived loamy topsoil of a Haplic Luvisol under agricultural use. Novelty is the simultaneous determination of contact angle and shrinkage of soils amended with digestates composed of different composition in maize, sugar beet and winter wheat, compost of shrub debris and sewage sludge. The results suggest that the application of organic residues impacts the air capacity, while the contact angles remained in the subcritical range between > 0° and < 90°. The relationship between CA values and moisture ratios, ϑ, during proportional shrinkage was positive and linear (r2 of 0.98) and negative during residual- and zero-shrinkage (r2 of 0.93).
The main purpose of this essay is critical. I focus on Robin Jeshion’s (2002; 2004; 2010) theory of singular thought, and I offer three objections to her Significance Condition for the creation of mental files. First of all, this condition makes incorrect predictions concerning singular thoughts about insignificant objects. Second, it conflicts with a theoretical aim mental file theories usually have, that of accounting for our ability to track discourse referents. And third, it appeals to a vague notion where a clear-cut notion is needed. In the final section, I suggest that there are more plausible alternatives to the Significance Condition that the mental file theorist could appeal to, and which do not face the problems mentioned., Hlavní cíl této eseje je kritický. Zaměřuji se na teorii singulární myšlenky Robina Jeshiona (2002; 2004; 2010) a nabízím tři námitky proti její podmínce významnosti pro tvorbu mentálních souborů. Především tato podmínka činí nesprávné předpovědi týkající se jednotlivých myšlenek o nevýznamných objektech. Za druhé, to je v rozporu s teoretickým cílem mentální souborové teorie obvykle mají, že účetnictví pro naši schopnost sledovat diskurz referents. A za třetí, apeluje na vágní představu, kde je zapotřebí jasného názoru. V závěrečné části navrhuji, aby existovaly více přijatelných alternativ k podmínce významnosti, na které by se mohl obrátit teoretik mentálních souborů a které by se těmto problémům nezabývaly., and Andrei Moldovan
Groundwater flow in surroundings of water structures is frequently noted for singularities in velocity field. These are induced by high gradients of velocity and pressure in closeness of slots and edges in structures. The study does analysis of some hydrodynamic properties of the singularities and warns against its possible incorrect model simulation. and Prúdenie podzemnej vody v okolí hydrotechnických stavieb ako sú potrubia, tunely, nádrže a plavebné komory sa často vyznačuje zvláštnosťami (singularitami) v rýchlostných poliach. Tie sú vyvolávané vysokými gradientami rýchlosti a tlaku v okolí netesností objektov, alebo ich núteným obtekaním. Štúdia analyzuje hydrodynamické vlastnosti týchto singularít a upozorňuje na dôsledky ich prípadne nesprávnej interpretácie.
In arid and semiarid regions where water is the main limiting factor, water redistribution is regarded as an important hydrological process of great ecological value. By providing additional water to certain loci, moist pockets of great productivity are formed, characterized by high plant biomass and biological activity. These moist pockets are often a result of runon. Yet, although runoff may take place on semi-flat undulating surfaces, runoff measurements are thus far confined to slopes, where a sufficient gradient facilitates downslope water harvesting. On undulating surfaces of mounds and depressions, such as in interdunes, no quantification of the amount of water reaching depressions is feasible due to the fact that no reliable method for measuring the runoff amounts in semi-flat terrains is available. The current paper describes specific runoff plots, designed to measure runoff in depressions (sinks). These plots, termed sink plots (SPs), were operative in the Hallamish dunefield (Negev Desert, Israel). The paper presents measurements of runoff yield that were carried out between January 2013 and January 2014 on SPs and compared them to runoff obtained from crusted slope plots and fine-grained (playa) surfaces. The potential hydrological and ecological implications of water redistribution within semi-flat terrains for this and other arid ecosystems are discussed.
Water erosion has been recognized as a major soil degradation process worldwide. This is of special relevance in the semi-arid areas of South Bulgaria with long periods of drought along with severe rainfall events. The main objective of this study was to evaluate the applicability of Bromus innermis L. and Lotus corniculatus L. for soil protection purposes under different site conditions. The site parameters considered were slope, fertilization and a range of soil physical parameters. The plant parameters were canopy cover, biomass, and root morphological characteristics. The experiment includes plots without and with eleven rates of NPK fertilization on gentle (6o ) and steep slopes (12o ). It was observed that the effect of fertilization on shoot and root growth was stronger on the gentle than on the steep slopes. The biomass accumulation was more sensitive to N than the PK fertilizer applications. The increase of the root density with increasing fertilization rates was more pronounced for the mass than for length or surface area. A significant effect on root diameter was found only for the variants with the highest N application. Treatments with the highest root mass density on both slopes showed the greatest potential for reducing erosion.