Károly Barta

Comparison of Pipette and Laser Diffraction Methods in Determining the Granulometric Content of Fluvial Sediment Samples

Abstract Nowadays there is a growing demand for rapid and accurate determination of grain size distribution. The conventional pipette method is time-consuming and provides less detailed data compared to recently introduced methods. However, in Hungarian practice the pipette method is still considered to be the standard one, as there are a long series of measurements, and grain size thresholds used in sedimentology and soil sciences are based on this approach. The aim of our research was to determine the comparability of the laser diffraction method (LDM) with the conventional pipette method (PM), in order to investigate the controversial question on the interchangeability of the two methods. Based on our measurements on some representative fluvial sediment samples, we found that the largest difference in results can be expected in the silty grain size range. However if the main fractions (clay, silt, sand) are considered the methods provided similar very results, and correlation factors were above 0.92. In all, the LDM has a clear advantage because of its speed, reproducibility and fewer possibilities for operator failure.

Multivariate Sampling Design Optimization for Digital Soil Mapping

In this study, we have extended the spatial simulated annealing (SSA) methodology to be able to simultaneously optimize a completely new sampling design for more than one pedological variable using regression kriging prediction-error variance (RKV) as optimization criterion. For this purpose, the following soil properties were chosen: soil organic matter content, rooting depth, calcium carbonate content, and plasticity index according to Arany. The number of new observations was set to 100. The methodology is illustrated with a legacy soil dataset and auxiliary information from a study site in Central Hungary. The combined structure of the regression models and the variogram of the dominant soil parameter were applied in the optimization process provided by SSA to calculate the quality measure (i.e., spatially averaged RKV). The resulted sampling design was evaluated by various statistical and point pattern analysis tools. The Kolmogorov–Smirnov test’s results and the observed empty space function showed that the optimized sampling configuration represents properly both the feature and geographic space. Furthermore, the empty space function pointed out that there is an inhibition between the sampling points, which caused a “quasi”-regular point pattern. The extended SSA methodology is suitable to optimize the sampling design for more than one soil variable.

Estimation of Soil Material Transportation by Wind Based on in Situ Wind Tunnel Experiments

Abstract 25% and 40% of territory of Hungary is moderate to highly vulnerable to deflation. However, precise estimates about the soil loss and related losses of organic matter and nutrients due to wind erosion are missing in most cases. In order to determine magnitudes of nutrient masses removed at wind velocities that frequently occur in SE Hungary, in-situ experiments using a portable wind tunnel have been conducted on small test plots with an erosional length of 5.6 m and a width of 0.65 m. The wind tunnel experiments have been carried through on a Chernozem which is typical for this region. In order to compare the effects of soil coverage on the masses of blown soil sediment and adsorbed nutrients, two soil surface types have been tested under similar soil moisture und atmospheric conditions: (1) bare soil (dead fallow) and (2) bare soil surface interrupted by a row of maize plants directed downwind along the center line of the test plots. The results of our experiments clearly show that a constant wind velocity of 15 m s-1 (at a height of 0.3 m) lasting over a short time period of 10 minutes can already cause noticeable changes in the composition and size of soil aggregates at the top of the soil surface. Due to the grain size selectivity of the erosive forces the relative share of soil aggregates comprising diameters > 1 mm increased by 5-10% compared with the unaffected soil. Moreover it has shown that short time wind erosion events as simulated in this study can result in erosion rates between 100 and 120 g m-2, where the erosion rates measured for bare soils are only slightly, but not significantly higher than those of the loosely vegetated ones. Soil samples taken from sediment traps mounted in different heights close to the outlet of the wind tunnel point to an enrichment of organic matter (OM) of about 0.6 to 1 % by mass referred to the control samples. From these findings has been calculated that the relocation of organic matter within short term wind erosion events can amount to 4.5 to 5.0 g OM m-2. With the help of portable field wind tunnel experiments we can conclude that our valuable, high quality chernozems are struck by wind erosion mainly in drought periods.

Testing a sequential stochastic simulation method based on regression kriging in a catchment area in Southern Hungary

Modelling spatial variability and uncertainty is a highly challenging subject in soil- and geosciences. Regression kriging (RK) has several advantages; nevertheless it is not able to model the spatial uncertainty of the target variable. The main aim of this study is to present and test a sequential stochastic simulation approach based on regression kriging (SSSRK), which can be used to generate alternative and equally probable realizations in order to model and assess the spatial variability and uncertainty of the target variable, meanwhile the advantages of the RK technique are retained. The SSSRK method was tested in a catchment area, in Southern Hungary for the modelling of spatial variability and uncertainty of soil organic matter (SOM) content. In the first step, the auxiliary information was derived according to the soil forming factors; then the RK system was built up, which provides the base of SSSRK. 100 realizations were generated, which reproduced the model statistics and honored the input dataset. These realizations provide 100 simulated values for each grid node, which number is appropriate to calculate the cumulative distributions. Using these distributions the following maps were derived: map of expected values, the corresponding 95% confidence interval’s width, furthermore the probability of the event of {SOM < 1.5%}, since this threshold value is highly informative in soil protection and management planning. The resulted maps showed that, SSSRK is a valuable technique to model and assess the spatial variability and uncertainty of the target variable. Furthermore, the comparison of RK and SSSRK showed that, the SSSRK’s E-type estimation and the RK estimation gave almost the same results due to the fairly high R 2 value of the regression model (R 2 =0.809), which decreased the smoothing effect.

Inland Excess Water Projection Based on Meteorological and Pedological Monitoring Data on a Study Area Located in the Southern Part of the Great Hungarian Plain

Abstract The research investigated the process of excess water formation. Complex measurement stations were developed in order to determine the most important hydro-meteorological and soil factors contributing to the formation of excess water. The stations measure the amount of precipitation, evapotranspiration, evaporation from water surface, soil moisture in 3 different depths; soil temperature in 5 different depths; furthermore, soil water level. The study area is located in the southeastern part of Hungary, near Szeged, in the flood plain of Tisza and Maros with extremely clayey soils. The former soil data were completed by new soil survey to determine several soil parameters (e.g. bulk density, porosity, field capacity, saturated hydraulic conductivity). Infiltration was calculated from the measured parameters and water budget elements of bigger rainfall event were analyzed between March 2010 and August 2011. Genetic types of excess water can be separated based on the data.

Használt termálvíz mezőgazdasági elhelyezésének (öntözés) hatása a talaj kicserélhető nátrium tartalmára és az összes oldott sótartalmára

Hazankban a szelsőseges vizhaztartasi helyzetek fokozodasaval a valtozo kornyezeti feltetelekhez valo alkalmazkodas megkoveteli az aktualis mezőgazdasagi gyakorlat modositasat az ontozes teruleten is. Az adaptacio egyik fontos eleme lehet az ontozeses gazdalkodasi formak kiszelesitese, a viz- es energiatakarekos ontozesi modok es modszerek előterbe helyezese es nem utolso sorban a hasznalt vizek (szennyvizek, hulladekvizek, elfolyovizek stb.), mint alternativ vizforrasok ontozeses hasznositasa. Kiserletunkben egy intenziv afrikai harcsa-nevelő telepről szarmazo hasznalt termalvizet es Koros vizet hasznaltunk fel energiafűz ontozesere egyeves lizimeteres kiserletben. Az ontozeses kiserlet a Nemzeti Agrarkutatasi es Innovacios Kozpont (NAIK) Ontozesi es Vizgazdalkodasi Onallo Kutatasi Osztaly (OVKI) szarvasi Lizimeter Telepen valosult meg. A kiserletben 82-es fűz klon nyolcfele ontozeses kezeleset alkalmaztuk. Eredmenyeink szerint a hasznalt termalviz minősege miatt ontozesre csak korlatozottan hasznalhato,...

Javaslat az antropogén talajok osztályozására a hazai, megújuló osztályozási rendszer keretei között

A drasztikus nepessegnovekedes, a mezőgazdasag intenzivve valasa es kemika-liak hasznalata, az ipari letesitmenyek es varosi teruletek terjeszkedese, az infrastruktura es a banyaműveles fejlesztese nagy teruleten eredmenyezi a talajtakaro alapos valtozasat, igy mara nelkulozhetetlenne valt az emberi hatasokra megvalto-zott vagy atalakult (antropogen) talajok termeszetes talajoktol valo elkulonitese, osztalyozasa. A jelenleg ervenyben levő hazai, genetikus es talajfoldrajzi alapokon nyugvo ta-lajosztalyozasi rendszerunk megujitasara, korszerűsitesere es a nemzetkozi iranyel-vekkel valo harmonizalasara iranyulo torekvesek kapcsan felmerult az antropogen talajok osztalyozasanak igenye es az uj hazai talajosztalyozasi rendszerbe illeszte senek szuksegessege. A tervek szerint tehat azon talajok elkulonitesere, melyekben az emberi tevekenysegek hatasa erőteljesen ervenyesul, egy kulon osztalyozasi alapegysegben, az „antropogen talajok” csoportjaban nyilik majd lehetőseg. E talaj-tipuson beluli altipusok, valami...

Mapping Freshwater Carbonate Deposits by Using Ground-Penetrating Radar at Lake Kolon, Hungary

Abstract Freshwater carbonate deposit, as a special phenomenon in the Danube-Tisza Interfluve, located in the centre of Hungary, is a significant geological heritage in the Carpathian Basin. At present there is not any applicable method to investigate the presence of carbonate layers in an undisturbed way, as neither vegetation nor morphological characteristics indicate unambiguously these formations. Ground-penetrating radar technology is widely used in various earth science related researches, and the number of applications is steadily increasing. The aim of the study was to determine the spatial extension of freshwater limestone using geophysical methods near Lake Kolon, Hungary. The lake, which is now a protected wetland area with opened water surfaces, was formed in the paleo-channel of the River Danube. Measurements were performed with the help of ground-penetrating radar, the results were calibrated by high spatial resolution drillings. Investigations have been made since 2012, and freshwater limestone was detected at several locations determining the more exact extension of the formation. Ground-penetrating radar proved to be an appropriate method to detect the compact and fragmented freshwater limestone layers in such an environment. However, based on the results the method can be best applied under dry soil or sediment conditions while the uncertainty of the results increases significantly as a matter of higher soil moisture. Further control measurements are necessary verified by several drillings in order to give an exact method to determine freshwater limestone.