Search

Search Results

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

  45-50

  Csaba Juhász

  Csaba Pregun

  Views:

  115

  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.

• Environmental Management Research on the Berettyó River

  161-165

  Csaba Pregun

  Péter Burai

  Views:

  61

  Our department is involved in ongoing research into the hydrological and ecological interplay of the Berettyó River.
  In the first part of our study we classified the Hungarian section of the river from ecological and hydrological standpoints. We determined three typical parts of the river: a sandy and gravely bottom, a middle part with a sandy and muddy bottom, and a lower part, with muddy bottom. In theese sampling areas we measured and established the more important static and dynamic hydrological, physical and chemical characteristics.
  For the planned research we did a primary estimation of the environmental condition of theese sampling areas, on the basis of applicable biological and ecological indication methods.

• Influence of Hydrological Parameters on the Biodiversity of the BerettyóRiver I.

  215-229

  Csaba Pregun

  János Tamás

  Views:

  96

  The DIRECTIVE 2000/60/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL orders the measurement of the state of natural and artifical waters. We therefore applied environmental qualification methods, which allow inductions of the searched area in environmental management, conservation and water quality protection points of view. These methods are accepted in interdisciplinary sciences, and are in use in Hungarian and international practice. We applied the range data measured along the Berettyó River, and ratified by the remote sensing, to count hydrological-hydraulical attributes of the stream, by the framework of the Hec-Ras programme. We processed the physical, chemical and biochemical water qualifications, determined the MMCP-index (the point-system of the Hungarian macrozoobenthos taxons), and estimated the Spencer index-numbers, which were based on complex environmental qualification and bioindication. Appointed, that the different results of researches are not inconsistent. This results together the spatial analysis reveal the natural and anthroponetic specialities of the river and the landscape, which determine the environmental flavours and biodiversity. The bioindicators represent better environmental status, than the physical, chemical and biochemical parameters. The natural conservationist importance of drainage canal network of Bihari-Plain is appreciated by these facts.