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An essential input for environmental studies, especially for hydrological simulations is the soil information, which is usually provided by spatial soil databases. Despite the growing number of related analyses little is known about the uncertainty associated to databases. This study aimed to evaluate this issue. (i) the World Soil Classification S...
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Hydrological processes are greatly influenced by the characteristics of the domain through which the process occurs. It is generally accepted that earth materials have extreme variations from point to point in space. Consequently this heterogeneity results in high variation in hydraulic properties of soil. In order to develop a predictive model for...
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... In arid and semi-arid areas, as in Iraq, where gypsiferous soils are found, the topsoil layers are mostly in unsaturated [4], [5]. The water content is low in the vadose zone relative to the saturated zone and referred to as the unsaturated zone [6], [7]. When the water rises in the porous media, it will displace the air until the pressure of the water level is in an equilibrium state [8]. ...
The phenomenon of capillary rise happens in soils, and it has a crucial effect on many engineering applications. Many researchers have concluded several experimental equations to estimate this height. This paper presents a comparative and practical study of the three most important equations used in most researches, which are Lane and Washburn, Fetter, and P-K equations. The estimated heights by these three equations were compared with the experimental tests on sand samples taken from Al-Adalah, Al-Furat, and Al-Jameah districts located in Al-Najaf city in the southwest of Iraq. The percentage change for each equation compared with the experimental work. The results illustrated that the Fetter equation is the closest equation to experimental height and gives moderate values, unlike the Lane and Washburn and P-K equations, to save estimation of the pollutants penetration in unsaturated soils.
... Inverse modeling, the automatic set up and simulation of scenarios as well as the statistical evaluation of simulation results were supported by the self-developed BHRalgorithm (Batched Hydrologic Runs Algorithm) [38]. The algorithm applies the nlopt open access program library [39] to aid the nonlinear local-global optimization tasks. ...
Historical trends in water management and recent climatic variations put wetlands in the Carpathian basin under strong pressure and led to their degradation. The lack of extended site specific environmental data series inhibits the understanding of long-term eco-hydrological processes. This undermines the success of restoration and/or management efforts. As a precedent we analyzed a recently degraded Hungarian lowland wetland, the Nyárjas fen in order to identify the main cause of its drying. Our method is based on one-dimensional simulations of a variably saturated soil column representing the dominant hydrological conditions of the wetland. To properly define the necessary soil hydraulic parameters, soil sampling, laboratory measurements and inverse modelling were carried out. The hydrological simulations for the 1961-2010 period clearly suggest that (i) the wetland degraded due to a temporal unfavorable combination of regional groundwater depletion and decreased precipitation, (ii) and could not recover afterwards despite the improvement of hydrological conditions. The ecological water demand of the Nyárjas fen can be explicitly expressed in terms of groundwater level. However, water availability is a necessary, but not sufficient criteria of good habitat status. The elaborated methodology provides the basis of bottom-up type environmental water demand estimation on a regional/national scale.
... The Tension zone Storage (TS) is determined in the model by calculating the difference between the water content at field capacity (set to 0.33 bar suction) and wilting point (Fig. 3b). The values necessary to compute the moisture curves were obtained from previous Hungarian studies [14], [15]. The final calibrated parameters are presented in Table I. ...
In order to promote long-term sustainable water management in northwestern
Hungary, decision-makers need to understand the hydrological variability in the region. To better
quantify hydrological variability in the region, this study developed rainfall-runoff models of four
watersheds in the Little Hungarian Plain. The models were then used to identify variations in
runoff characteristics caused by climatic factors or fundamental alterations to the watershed itself
through the application of numerical error analysis. By observing the continuous statistical error
measurements, changes can be detected in either climatic conditions, watershed characteristics, or
may indicate gauging or data collection errors.
... The Tice, an old river branch of the Tisa River, represents a significant wetland system, which is part of the NATURA 2000 nature protection areas. The proposed contribution deals with a determination of the input parameters for the definition of the infiltration properties of soils [2] located directly in the riverbeds of the drainage channels in the area of interest (Fig. 1). These parameters are necessary for estimating the water losses (infiltration into the subsoil) in a hydraulic assessment of the possible waterlogging of the wetlands system of the 44 km-long Tice River through the existing drainage channel system. ...
Drainage channels are artificial multi-functional elements in a landscape, which have their own specific functions. Although they are primarily used for the drainage of water, they can also even be used for an opposite function, i.e. the artificial water supply of specific regions. This article presents an evaluation of infiltration experiments in drainage channels in the southeastern part of Slovakia. These experiments served for the collection of input data for numerical modeling, especially the determination of the soil type and hydraulic conductivity. The methodology of experimental works in the field as well as some basic information about their evaluation is included.
... [18]). These parameters were used only as initial estimates because previous researchers [19] found that class averages provide poor representation of conductivity in soils. Variations of unsaturated behavior within certain classes may exceed the difference in averages between classes. ...
The western shoreline of the Danube from Érd to Mohács consists of loess bluffs up to 50 m high. These bluffs can be susceptible to landslides when groundwater conditions weaken the supporting loess. Often this will occur during periods of high rainfall, however morphological, geological and other factors are also important in triggering these movements.
Changes in pore water pressures related to precipitation, confined water levels driven by remote catchments, and river level fluctuations are widely recognized as important factors controlling the loess bank stability. This work aims to determine the interaction of rainfall, river level, drainage and local pumping on the pore pressure regime and stability of the bluffs.
As a first step, a realistic 2-dimensional infiltration and groundwater model was built that reflects the influence of river levels, rainfall patterns, and local pumping. Based on model results, initial and boundary conditions have a strong influence on seasonal pore pressures. Further study will better define those influences on slope stability along the bluffs.
... The term 'geological parameters' represents the top and base of the aquifer [10], and the term 'hydrogeological parameter' represents the hydraulic conductivity k ( Table I) [11]. Sedláček Island fine and medium-grain sands 7.2 -14. ...
The water sources located on the inland islands on the left side of the Danube River as well as water sources located on the right bank of the Danube River in the Pečniansky forest have an irreplaceable function in terms of supplying the population in Bratislava with drinking water. There are 80 wells in these mentioned areas operated by the Bratislava Water Company. In order to maintain the actual functions of the water resources, it is therefore necessary to assess the impact of the proposed construction of the multi-purposed structure 'Hydraulic structure Bratislava - Pečniansky forest' on these water sources.
... Concerning the aspects above, recently a research was started with the aim to (i) quantify the uncertainty related to classified soil data used for hydrologic modelling, and to (ii) derive useful information and hydrologic indicators for soil samples from Hungary. In the first phase of the study (Kozma et al. [8]) the well-known FAO classification system (FAO [9]) was analysed by using it on the Unsaturated Soil Hydraulic Database of Hungary (HUNSODA -Nemes [10]). Three possible directions were outlined for the second phase of the research: ...
... In the first phase of this research FAO classes of the HUNSODA database showed significant uncertainties in soil hydraulic parameters (Kozma et al. [8]). Therefore the database has been categorized and analyzed also with the USDA method. ...
Physical and hydraulic soil properties are essential input parameters for models from different sciences (e.g. hydrology, agriculture, water management, nature preservation). Generally texture composition, porosity and other easily measurable physical properties of soils are known. However, saturated hydraulic conductivity and characteristic values of the water retention curve are usually missing information. Therefore, based on the physical similarity of soils (classes), they are substituted by data derived from soil databases. The aim of this study was to assess the currently unknown uncertainties of such classified databases. To do so, a large variety of tests were carried out: (i) static and dynamic, (ii) 1D and 3D (iii) hydraulic and hydrologic applied tests, (iv) real and synthetic soils, parameterized accordingly, and (v) HUNSODA and/or HYPRES databases. The results were sorted with respect to FAO and USDA classification systems. Soil class overlapping was evaluated through the statistics of basic hydraulic parameters (retention curve, hydraulic conductivity). Indicators related to hydrologic extremities (excess water and drought) were used to quantify the uncertainties of soil texture based on parameter substitution. It was concluded that the two evaluated soil classification systems did not sort soils reliably from the hydrologic and hydraulic viewpoint: the test results of classes showed major overlaps. Moreover, in most cases class synthetic parameter combinations poorly represented real soils. As a general consequence the results based on classified soil databases should be accepted only with reservation.
Can the analysis of numerical modeling errors indicate changes in a watershed? In this research, we are working on analyzing the errors using two different methods.
