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Assay of runoff conditions using a Digital Elevation Model
124-129Views:91We can get information about water conditions of plane areas by analyzing their relief. By using the Digital Elevation Model, we can get proper information about runoff conditions in the terrain surface, which is the basis for ponding analysis. In our study, a Digital Elevation Model of the sample plot in Hajdúsági-löszhát (loess ridge) was created that makes possible the determination of runoff conditions of the surface. Convergence and divergence of runoff direction showed the rate of ponding and the location of possible inland-water spots. By using this model, concrete location of those areas that tend to be overmoistured could be determined. Knowledge of this phenomenon can be an effective instrument for farmers in optimizing crop growing, and additionally in performing water management interventions in proper time and space.
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Examination of the conditions of extreme water balance circumstances (water logging, drought) with environmental information technology tools
79-86Views:185The 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.
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Application of hydrological models for agri-environmental management based on international and national experiences
45-50Views:115The 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.
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Causes of floods and flood protection in Subcarpathia
72-75Views:90Subcarpathia is one of the richest regions in surface waters in the Ukraine. Due to its geographical, relief and climatic conditions, it belongs to the active precipitation zone, where great floods frequently occur. As a result of many years of observation, it can be concluded that the interactions of many natural factors can lead to various floods in the catchment area of the river Tisza. These are mostly hydro-meteorological factors, which can lead to great floods with the characteristics of the formed flow. Human activity also significantly influences the occurance of floods: clearing, which can accelerate the process of the runoff, ploughing in the catchment area, which can lead to erosion and the utilisation of areas endangered by floods for various economic sectors.
A series of questions arose in recent years regarding the formation of floods: what could be the causes of floods and what actions need to be made to prevent them. The evaluation of floods made us conclude that passive protection by using dams does not always ensure protection against floods as these were constructed in different times for different water levels. Many factors can affect the whole process which cannot be foreseen, therefore the development of new solutions and new technologies is necessary in flood protection. -
Characterisation of basic water balance parameters of Debrecen
35-40Views:148This work aims to develop a hydrological modelling tool to help managers make the right decisions for Debrecen, in the face of water scarcity and the increase in agricultural and domestic needs over time. The methodology was based on the creation of a climatic database, at monthly time steps, from 2016 to 2019, and cartographic (land use, digital elevation model, and hydrological network). As a next step, the watershed was delimitated into sub-basins to determine the shape and the physiographic characteristics of sub-watersheds. Finally, a hydrological study was prepared by calculating the time of concentration to build a database of water resources in the study area. This water resource will be used as an input parameter for urban farming.
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Water infiltration into the soil – what do measurements indicate?
343-351Views:141Physical properties of top-soil organic materials significantly influence initiation processes of infiltration and runoff generation. This paper deals with the specifics of water infiltration through the top surface organic layer of the forest soil. Three field methods (Guelph permeameter, Tension disk permeameter, Single-ring method) and one laboratory method (Falling head) of hydraulic conductivity (KS) determination are compared and interpreted in the context of their applicability and limitations. The Falling head method provides far different values of KS if sample cylinders are or are not sealed with grease against the wall effect. The Guelf permeameter is very significant to the position of different horizons’ interface, while Tension disc permeameter results are dependent on antecedent soil moisture. The single ring method is applicable with acceptable results only when there is no abrupt interface between horizons in the vicinity of the ring bottom edge.
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Preliminary estimation of the efficacy of Fusarium sporotrichioides Sherb. as biological control agent against common milkweed (Asclepias syriaca L.)
201-204Views:248A study of fungi responsible for severe leaf spots of common milkweed (Asclepias syriaca L.) in the Hajdúság region (East Hungary), Fusarium sporotrichioides and Alternaria alternata were isolated from infested leaf tissues. F. sporotrichioides was the most virulent fungus in pathogenicity tests conducted on healthy leaves of common milkweed plants. Inoculation of common milkweed (A. syriaca) in different growth stages with F. sporotrichioides yielded similar symptoms as the original ones. Spray mixtures containing 1.0×106 conidia/ml gave effective control when common milkweed plants were sprayed until runoff occurred. Laboratory (wet chamber) and field experiments showed that asexual spores of the fungal pathogen, F. sporotrichioides, exhibited bioherbicidal activity against common milkweed (A. syriaca).
More efficient control efficacy was observable on elder plants (at flowering stage) than younger ones. These results initiate that this fungus may be a biocontrol agent for controlling this invasive weed but should clarify its hosts because it could infect cultivated plants as well.