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  • Studying the development of fluvial landforms in the Berettyó-Körös Region using geoinformatic methods
    137-144
    Views:
    157

    Development of fluvial landforms from 1980 till nowadays was studied based on digital elevation maps
    (DEM) composed from contour lines of topographic maps, field data obtained by RTK GPS and aerial
    photos taken by a drone. Greatest denudation of 6-9 metres was measured in the eastern side of the
    erosional valley at Pocsaj caused by piping and mass movements. As a result, the valley widened and
    slightly deepened. Since 1980 around 1-2 metres of accumulation and erosion of similar rate have been
    measured in the secured floodplain environment dissected by abandoned beds, point-bars and swales
    at Kismarja. These values, however, rather reflect the geometric uncertainties and deficiencies of the
    contours of topographic maps than real land changes. Therefore topographic maps can give reliable basis
    for studying the development of lowland landforms only if they depict adequately large sized (minimum
    100 x 100 m) positive or negative forms with great height difference as well (minimum 8-10 m). Accuracy
    of DEMs composed from aerial photos using photogrammetric methods – taking off height faults caused
    by vegetation – is around the same as that of the models created on the basis of RTK GPS measurements.

  • Environmental monitoring using linden tree leaves as natural traps of atmospheric deposition: a pilot study in Transilvania, Romania
    24-35
    Views:
    106

    Atmospheric pollution caused by toxic elements is an emerging problem of concern. Tree leaves have
    been widely used as indicator of atmospheric pollutions and they are effective alternatives to the more
    usual biomonitoring methods. Tree leaves can be used as natural traps of atmospheric deposition.
    Elemental composition of dust deposited onto leaf surfaces can be used to characterize the urban
    environment. A pilot survey including 16 Romanian settlements was carried out in order to evaluate
    the characteristics and sources of air pollutants. Tree leaves (Tilia tomentosa, Tilia cordata, Tilia
    platyphyllos) were collected and used for the measurements. Elemental analyses were carried out by
    ICP-OES and ICP-MS. Principal component and discriminant analyses were used to characterizing
    and estimating the level of pollution. Settlements were grouped on the basis of discriminant function
    values. Multivariate comparison of chemical data ordered the settlements into 3 main groups, which
    showed a systematic geographic distribution.