Search

Published After
Published Before

Search Results

  • Examination of the conditions of extreme water balance circumstances (water logging, drought) with environmental information technology tools
    79-86
    Views:
    185

    The Carpathian Basin is characterized by varying hydrological extremes, both in space and time. Hungary's natural endowments are more favourable than average, especially for agricultural production, with 5,3 million hectares of land we have which is suitable for agricultural production. These extreme water management are often occur in the same year and mostly in the same region, which may become more frequent in the future, especially in the lowland regions. The negative impacts of extreme water management was influenced by the land use changes in recent years, which has modified the runoff processes of the affected regions.

    The aim of the study was to research the formation of inland water and drought circumstances in two sample areas the Great Plain (Szolnok-Túri flat and Nyírség) by geoinformatic tools. During the investigation in the first step we determined that areas which are susceptible to inland water and drought, based on the AGROTOPO database. In addition, land-use categories of characteristics of the sample areas are evaluated according to the Corine Land Cover. Furthermore, after defining characteristic of NDVI values between the period of 2003–2013, we evaluated the effect of drought whether can be detected in crop failures in respective areas.

    Based on our results, we concluded that the formation of inland water and drought circumstances can be investigated in a large spatial extension by geoinformatic tools and databases.

  • Investigation of Salix alba and Populus tremula leaf litter decomposition in the area of Lake Balaton and Kis-Balaton Wetland
    159-162
    Views:
    158

    Plant litter decomposition in inland waters contributes significantly to nutrient load, particularly in still waters, such as shallow lakes and wetlands. The decomposition rates of Salix alba and Populus tremula leaf litter was examined in Lake Balaton and Kis-Balaton Wetland, using litter bag technique. Leaf litter was incubated in small (ᴓ=3 mm) and large (ᴓ=900 μm) mesh size bags for the assessment of the relative contribution of macroinvertebrates to leaf litter decomposition. Dry mass, exponential decay coefficient and chemical parameters of water (pH, conductivity, NH4 +, NO3 -, SO4 2-, PO4 3-, Cl-) were determined. Leaf mass loss showed negative exponential pattern during the 168 days of the decomposition period. Leaf litter mass loss generally did not differ between the small and large mesh sizes, suggesting that macroinvertebrates generally have a negligible role in leaf decomposition in the winter period.

  • Complex assessment of inland water fish stocks
    74-80
    Views:
    69

    In the domestic fish production, natural waters have yielded for several years about 7-8 thousand tons. This, from the point of view of outputs, considering the almost 130 thousand hectares of natural water, is rather low, it means approximately 55-60 kg/ha mixed fish.Although the various natural waters can differ significantly on the basis of yields, yet on the majority of the territories, the results were low. In the case of our extensive still waters and rivers, the reason can undoubtedly be found in the combined effect of the lack of the possibility of reproduction of the fish stock and the over-fishing. Fishery built on planning supposes the best possible knowledge in the given circum stances of the parameters of the water area and its fishstock. Lacking this knowledge, it is not possible to establish the optimal use fulness of the resources, what is more, the management can make faulty decisions – as a result of a lack of information -, which can risk the success of later activities.
    It is known that many factors have an impact on the success of the fishery, as well as some information in connection with the water area and the fish stock are necessary, the knowledge of which make it possible to manage the fishery in a planned way. One part of the information is available, while the other part is incomplete or not deep enough. The necessary data are dissimilar depending on their nature, can be obtained from different places, by different methods.
    As the first step for executing the field surveys and processing data, I developed a complex model, which contains in a unified system the steps of estimating the fishstock. I made the sampling on the basis of this. Part of the model is a fish faunistic survey, as well as a morphological survey of the water area. The information gained from these are important for making more accurate the system of devices of the samplings for stock estimation (duration, number of net-rows) and for assigning its place (places representing the best way the physical characteristics of the given water area). The major stages of stock-survey: A) faunistic survey, B) physical survey of the bed, and C) sampling with the help of gill-nets. This is followed by the evaluation by the computer module.
    The results of the research create a methodological and technical background for the fish faunistic and population biologic surveys still performed in different ways in our country, and by applying these methods together, all basic information about natural waters which help decision-making concerning fisheries can be obtaine deffectively.

  • Analysis of the Relation Between the Relief and the Surface Water Network
    90-93
    Views:
    53

    The Bihar plain situated in the Great Hungarian Plain has altitudinal values between 87 and 108 meters above Baltic level and these low average values decreases from East to West. We can find on this place a surface water network with a high density; the most of them was created for diversion of inland water.
    The GIS is the best practice for modelling and simulating the relief and the water network. Towards the creation of the TIN model and relief- analysis we need the digital elevation model as well as the digital water network dataset for the whole territory. The source of the data was topographic maps on high scale level (1:10.000).

  • Effect of season and sowing time on the moisture loss dynamics and yield of maize
    255-265
    Views:
    149

    The effect of sowing date on maize development and yield was studied in field experiments. The experiment was set up at the experimental garden of the University of Debrecen Centre of Agricultural Sciences Faculty of Agriculture, Department of Plant Sciences in 2005 and 2006 on calcareous chernozem soil. Six hybrids with different genetic characteristics and vegetation period were tested (Sze 269, DK 440, PR37D25, NK Cisko, Mv Maraton, PR34B97) at three different sowing dates.
    2005 was a very wet year. The amount of precipitation in the vegetation period was about 150 mm higher than the average of 30 years. No significant differences were observed in temperature. However, the number of sunny hours was much lower during the summer than as usual. This had an influence on yields.
    In 2006, there was no risk of inland water in spite of the large amount of precipitation at the beginning of the year. The amount of water available for plants was satisfactory during the season due to the favorable amount of precipitation. Therefore, plants suffered less from the heat in July. However, hail on 22 July caused significant damage. The number of sunny hours in the summer was high enough. The warm, dry autumn helped the water release of plants.
    In 2005, the results of the third sowing date could not be evaluated due to the large number of missing plants. The yield of hybrids ranged between 12-14 t/ha for the first sowing date. For the second sowing date, yields ranged between wider boundaries. The hybrid PR37D25 has a very high yield in the case of the second sowing date, and its seed moisture content was favorably low. The yield of hybrid PR34B97 was the lowest at the later sowing date, the prime reason of this was damage caused by Diabrotica virgifera. The seed moisture content at harvest varied between 16-24% for the first sowing date. In the case of the second sowing date, higher values were measured. Hybrids Sze 269 and NK Cisko had favorable water release characteristics. The maximum value of leaf area index was the best in the case of the first sowing date (5-5.5 m2/m2).
    In 2006, yields for the first sowing date ranged between 8-10 t/ha. At the second sowing date, more favorable results were obtained. The reason for this is probably that hail caused a higher damage in hybrids with the early sowing date. Plant stock with later sowing date could recover more successfully. Hybrid PR37D25 had very high yields for the second and third sowing dates. The high-yielding hybrid PR34B97 also had high yield, but this was accompanied by higher seed moisture content. Due to the warm, sunny autumn weather, the hybrids had good water-release dynamics and were harvested with a lower seed moisture content than in the previous year. For the first sowing date, the seed moisture content was around 13-14% except for hybrid PR34B97. For the second and third sowing dates, higher values were observed. Leaf area index was significantly reduced in August for all three hybrids due to the hail in July. For the first two sowing dates, the leaves of hybrid Sze 269 were the first to dry similarly to the previous year.
    Year had a strong effect on the results in both years.

  • Opportunities of delineating inland waters and soil moisture with remote sensed data
    95-98
    Views:
    104

    The methodology for delineating water bodies on multispectral remote sensing imagery was examined and evaluated. A supervised approach is tested with the aim to accurately detect inland water, moisturised soil surface and swampy patches on the Landsat TM 7 scene. The goal of this research is to investigate whether the application of remote sensing image interpretation could further refine the possibilities of future soil conductivity measurement research. The methodologies used were the application of supervised classification algorithms based on the training data collected in the area. The achieved overall classification accuracy value of 83.0795% suggests that the methodology could be used as a successful strategy to incorporate remote sensing data interpretation into soil conductivity measurement planning and application. The main conclusion that can be drawn is that processing of multispectral data with further refinement of the presented methodologies can led to very useful outcomes for environmental measurements.

  • The Importance of Environmental Research of the Great Hungarian Plain
    9-16
    Views:
    63

    The research of the Great Hungarian Plain has been going on for a long time and there are a lot of information could be used by environmental protection too. The connection between the two topics are diversified, that is why it is necessary to choose a few subject to explain. The chosen subjects are:
    The protection of the geological media cannot be solved, either practically and legally, with the protection of the separated elements of that, just if we see it as a system.
    The prevention, which is the most effective (and also the most inexpensive) way of environmental protection, can be supported by the compilation of vulnerability- and risk maps (i.e. risk of inland water, erosion vulnerability, deflation vulnerability, contamination sensibility).
    Survey on the environmental state containing indispensable geological information for the optimal land use and country planning of a region, county or settlement.
    Marking out of the possible areas for waste depositing.

  • Using the principles of precision animal husbandry in fishbreeding
    283-287
    Views:
    180

    Aquaculture species such as fish, crayfish, molluscs and plats are a wide range of products, with continuously growing demand worldwide. The reasons for this is that they are cheap and easy-toraise protein sources, thus having significance in food supply especially in developing countries in tropic regions, moreover, the premium category foodstuffs in developed high income countries are also belonging to this category. World annual total production of 164 million tons (2009) are made up of two sources: 1) marine and inland fisheries landings that are stagnating for several years and 2) aquaculture which is growing dynamically with annual 6% rate between 2000–2009. The latter is accounting for nearly 45% of the total supply due to the depleting marine stocks caused by overfishing. Aquaculture is growing continuously also because the production is safe and can
    be planned well. 
    Intensive fish production systems are the representatives of precision animal production, several types exist and widespread worldwide. The modern computerized temperate water recirculation plants with several thousand m3 capacity are widespread also in Europe because they make it possible to produce even the most valuable species whole year round. A key issue in the technical/feeding outlay is to meet the demands of the cultured species the best and the operation of the system is to be safe and cost-effective. One condition for this is intensification: enable to produce more product per unit resource input or effort. The facilities need significant amount of energy, thus renewable energy sources are to be favoured for which Hungary has comparative advantages.

  • New Possibilities of Brown Bullhead (Ictalurus nebulosus) Farming
    55-57
    Views:
    86

    The brown bullhead (Ictalurus nebulosus) has been settled in Europe at the end of Century XIX from North America. In Hungary it has been brought in 1902. The naturalization of this species was successful because the brown bullhead found adequate conditions for its life and reproduction in Hungary. But it was unsuccessful because lost its excellent growth.
    In inland water habitats-and that’s why also fishponds-extraordinarily multiplied, but because of its slight growth this species is undesirable for the native farmers. The brown bullhead is concurrent for domestic fish species, on the other hand its weight not more than 150-200 g. Occasionally it was exterminated, but multiplied again and again.
    In 1999 we placed out black bullhead offspring in a pool of a new intensive fish farm, in order to breed at least 300-350 g weight for the customers. The accidental trial was surprisingly successful. Consequently, the black bullhead prefers the artificial food, and produces excellent growth parameters and specific feed-live weight conversation ratio.
    On the 20th of September 1999 there was placed 23 300 pieces of brown bullhead offspring, with 28 g average weight and 625 kg gross weight. When we sold them on the 22nd of February 2000, the gross weight was 3387 and the live weight gain was 2735 kg. The gross weight of the feed was 3041,8 kg, and the feed-live weight conversation ratio was 1,11 kg/kg.
    Because of this successful trial the managers of the farm wanted to start systematic experiments to work out the details of the intensive farming of brown bullhead. We undertook to help to find the right place of the species in the Hungarian fish processing because of the increasing native and foreign demand.