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• The developement of red mud flood environmental information system and the methodology for the spatial analysis of the degraded area

  1-11

  Gábor Bakó

  Gábor Kovács

  Zsolt Molnár

  Judit Kirisics

  Eszter Góber

  András Ambrus

  Views:

  216

  The red mud disaster occurred on 4th October 2010 in Hungary has raised the necessity of rapid intervention and drew attention to the long-term monitoring of such threat. Both the condition assessment and the change monitoring indispensably required the prompt and detailed spatial survey of the impact area. It was conducted by several research groups - independently - with different recent surveying methods. The high spatial resolution multispectral aerial photogrammetry is the spatially detailed (high resolution) and accurate type of remote sensing. The hyperspectral remote sensing provides more information about material quality of pollutants, with less spatial details and lower spatial accuracy, while LIDAR ensures the three-dimensional shape and terrain models. The article focuses on the high spatial resolution, multispectral electrooptical method and the evaluation methodology of the deriving high spatial resolution ortho image map, presenting the derived environmental information database.

• UAS photogrammetry and object-based image analysis (GEOBIA): erosion monitoring at the Kazár badland, Hungary

  169-178

  László Bertalan

  Zoltán Túri

  Gergely Szabó

  Views:

  264

  A remarkable badland valley is situated near Kazár, NE-Hungary, where rhyolite tuff outcrops as greyish white cliffs and white barren patches. The landform is shaped by gully and rill erosion processes. We performed a preliminary state UAS survey and created a digital surface model and ortophotograph. The flight was operated with manual control in order to perform a more optimal coverage of the aerial images. The overhanging forests induced overexposed photographs due to the higher contrast with the bare tuff surface. The multiresolution segmentation method allowed us to classify the ortophotograph and separate the tuff surface and the vegetation. The applied methods and final datasets in combination with the subsequent surveys will be used for detecting the recent erosional processes of the Kazár badland.

• Studying the development of fluvial landforms in the Berettyó-Körös Region using geoinformatic methods

  137-144

  Csaba Albert Tóth

  Norbert Barkóczi

  Richard William Mcintosh

  Zsolt József Plásztán

  Views:

  181

  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.