A Kis-Balaton Vízvédelmi Rendszer hosszútávú adatsorainak elemzése

Az utóbbi évtizedekben a felszíni vizeink min sége fokozottan romlott. Ez els sorban az antropogén tevékenységeknek tudható be. Az emberi népesség növekedésével rohamosan megn tt a vízhasználat, így fokozott figyelmet kell szentelnünk vízkészleteink meg rzésének. A vízmin ségromlás szempontjából az édesviz sekély tavak a legveszélyeztetettebbek. A tavak vízmin ségromlásának els dleges forrása a szervetlen növényi tápanyag, amely eutrofizációt okoz a víztestekben. Ez a folyamat lehet természetes és antropogén eredet is. A természetessel szemben az antropogén eredet eutrofizációt kiváltó tényez k (bemosódó m trágya, vízszennyezések, stb.) hirtelen és nagy volumennel hatnak az ökológiai rendszerekre, túlterhelik azokat, így haváriák következhetnek be. Közép-Európa legnagyobb sekély viz tava a Balaton, amelyben az ember környezetátalakító tevékenysége nagy mérték eutrofizációt okozott. A Balaton egyedi fekvése, természeti értékei és felbecsülhetetlen él világa egész Európában egyedi, így els dleges feladatunk e nemzeti kincsünk meg rzése. Erre a feladatra hivatott a Kis-Balaton Vízvédelmi Rendszer (KBVR), amely els sorban a Zala vizében szállított szervetlen növényi tápanyagokat sz ri meg. Jelen dolgozat célja, hogy az 1984-t l rendelkezésre álló kémiai, biológiai és fizikai paraméterek adatelemz módszerekkel történ vizsgálatával mutassa be a Kis-Balatonban zajló, illetve már lezajlott folyamatokat. Tudomásom szerint a KBVR-r l nem készült vizsgálat, ami ilyen hosszú id tartamot ölelne fel. A Kis-Balaton Vízvédelmi Rendszer a mai napig befejezetlen, így nagyon fontos, hogy a szakmának minnél több információ és vizsgálati eredmény álljon rendelkezésére, amikor megtervezi és elkezdi a II. ütem befejezését. Szerény eszközeivel ehhez kíván hozzájárulni ez a dolgozat

Water chemistry analysis in the sediment of Baradla Cave, Hungary

Abstract Water was observed in the sediment of Baradla Cave, located in Northeast Hungary. In order to investigate its characteristics wells were drilled. Hydrochemical samples were taken directly from the wells and from the cave stream on several occasions between November 2009 and April 2010. In February 2010 there was an opportunity to observe how the chemical composition of the waters of the creeks and the sediments altered during the snow melt. Several chemical parameters of the samples were analyzed. Based on the results of the hydrochemical analyses cluster analysis was applied to define the relationship between the sampling points. Discriminant analysis was conducted to verify the classification. As a result of the classification, the water of the observation wells in the sediment proved to be distinct from the water of the cave's creek and the springs on the surface. Research shows that there is no permanent connection between the water in the cave sediment and the water of the cave creek in the cave water system

Geostatistical analysis and isoscape of ice core derived water stable isotope records in an Antarctic macro region

Water stable isotopes preserved in ice cores provide essential information about polar precipitation. In the present study, multivariate regression and variogram analyses were conducted on 22 delta²H and 53 delta¹⁸O records from 60 ice cores covering the second half of the 20th century. Taking the multicollinearity of the explanatory variables into account, as also the model's adjusted R² and its mean absolute error, longitude, elevation and distance from the coast were found to be the main independent geographical driving factors governing the spatial delta¹⁸O variability of firn/ice in the chosen Antarctic macro region. After diminishing the effects of these factors, using variography, the weights for interpolation with kriging were obtained and the spatial autocorrelation structure of the dataset was revealed. This indicates an average area of influence with a radius of 350 km. This allows the determination of the areas which are as yet not covered by the spatial variability of the existing network of ice cores. Finally, the regional isoscape was obtained for the study area, and this may be considered the first step towards a geostatistically improved isoscape for Antarctica

The application of Magnetic Resonance Imaging (MRI) to the examination of plant tissues and water barriers

The aim of the present study is to extend the applicability of MRI measurements similar to those used in human diagnostics to the examination of water barriers in living plants, thus broadening their use in natural sciences. The cucumber, Cucumis sativus, and Phillyrea angustifolia, or false olive, were chosen as test plants. The MRI measurements were carried out on three samples of each plant in the same position vis-a-vis the MRI apparatus using a Siemens Avanto MRI scanner. Two different relaxation times were employed, T1 capable of histological mapping, and T2, used for the examination of water content. In the course of the analysis, it was found that certain histological formations and branching cause modifications to the intensity detected with relaxation time T2. Furthermore, these positions can also be found in T1 measurements. A monotonic correlation (cucumber: ρ = 0.829; false olive: ρ = –0.84) was observed between the T1 and T2 measurements. In the course of the statistical analysis of the signal intensities of the xylems it was concluded that they cannot be regarded as independent in a statistical sense; these changes rather depend on the anatomic structure of the plant, as the intensity profile is modified by nodes, leaves and branches. This serves as a demonstration of the applicability of MRI to the measurement of well know plant physiological processes. The special parametrization required for this equipment, which is usually used in human diagnostics, is also documented in the present study

Speleothem stable isotope records for east-central Europe: resampling sedimentary proxy records to obtain evenly spaced time series with spectral guidance

Uneven spacing is a common feature of sedimentary paleoclimate records, in many cases causing difficulties in the application of classical statistical and time series methods. Although special statistical tools do exist to assess unevenly spaced data directly, the transformation of such data into a temporally equidistant time series which may then be examined using commonly employed statistical tools remains, however, an unachieved goal. The present paper, therefore, introduces an approach to obtain evenly spaced time series (using cubic spline fitting) from unevenly spaced speleothem records with the application of a spectral guidance to avoid the spectral bias caused by interpolation and retain the original spectral characteristics of the data. The methodology was applied to stable carbon and oxygen isotope records derived from two stalagmites from the Baradla Cave (NE Hungary) dating back to the late 18th century. To show the benefit of the equally spaced records to climate studies, their coherence with climate parameters is explored using wavelet transform coherence and discussed. The obtained equally spaced time series are available at https://doi.org/10.1594/PANGAEA.875917