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• Usage of different remote sensing data in land use and vegetation monitoring

  7-12

  Péter Burai

  Views:

  129

  The use of remote sensing in forest management and agriculture is becoming more prominent. The rapid development of technology allowed the emergence of database suitable for precision application in addition to the previously used low-resolution and low data content images. The high resolution, hyperspectral images are not only suitable for separating the different land use categories and vegetation types but also for examining the soil characteristics and biophysical features of plants (Blackburn and Steel, 1999; Condit, 1970). We processed a multispectral satellite image (Landsat 7 ETM+) and a hypespectral areal image (DAIS 7915) about a farm on the plains and evaluated the different image classification methods. During our examinations, we examined the geometrical and radiometrical characteristics of images first, then assigning the training areas, we determined the spectral characteristics of land use categories. We performed a multispectral analysis for checking land use, where we compared controlled and uncontrolled classification systems to check their reliability. We used areal and spectral reductions to make the classifications more accurate and to reduce the length of calculations.

• Experiences of Establishing Up-To-Date On-Site Sampler Applications

  210-241

  Sándor Pázmányi

  Attila Dobos

  Views:

  79

  Spatial problems and spatial decisions are decisive in agricultural-environmental informatics systems and the solutions require systems that can collect, evaluate and display spatial data. The distinctive features of spatial informatics systems therefore have to be considered when establishing integrated spatial informatics systems.
  However, the prepared spatial evaluations are not the only „added value” elements of a completed informatics system. The method of access can also speed up the work of participants and the whole system, making it more efficient with simple data-handling and the application of open standards. The significance of prepared database archives can also increase, since the accumulated data-assets are easy to utilize and become marketable.

• Application of hydrological models for agri-environmental management based on international and national experiences

  45-50

  Csaba Juhász

  Csaba Pregun

  Views:

  128

  The ecological restoration of surface water flows requires the use of complex GIS and hydrological models. The HEC -RAS and MIKE11 programs calculate the hydraulic characteristics of runoff using the geometry and bed resistance the of flows. The presentation of some possible applications made through an example of the Berettyó, which is an extremely regulated river. The river belongs to the meandering category by Parker's classification system, which uses the relationship of the slope-Froude number and the depth- width ratio. Three coefficient of the four determining factor (entrenchment ratio, slope of water level, width-depth ratio) also indicates a mediocre to high sinuosity, while the river regulations established nearly straight bed-line. The standard water flow rates and characteristics have been determined based on the modeled Froude and Reynolds numbers. The flow conditions shifted to the laminar type by the changed line drawing which is ecologically lower status. Based on the results the morphological and ecohydrological river rehabilitation is appropriate.