32 research outputs found

    Hydrogeological approach to the regional analysis of low flow in medium and small streams of the hilly and mountainous areas of Serbia

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    During the long rainless spells of the dry season, flows in medium and small streams get reduced to what is generally known as "low flow". For ungauged streams, the controlling "low flows" are determined using the regional analysis method. In the presently described exploration, the method applied was based on the assumption that dry weather discharges in medium and small rivers depended on the hydrogeological conditions. The controlling effect of hydrogeology on the natural low flow in medium and small streams of the hilly and mountainous part of Serbia was analyzed applying the theory of multiple linear regression. The thirty-day minimum mean 80 and 95 per cent exceedance flows were taken for dependent variables, and quantified hydrogeological elements as independent variables. The analysis covered streams that had small or medium size catchment areas. The treated example encompassed sixty-one gauged catchments. The resulting regional relations for the thirty day minimum mean 80 and 95 per cent exceedance flows are presented in this paper. The quality of the established relation was controlled by relevant statistic tests

    Land use change for flood protection: A prospective study for the restoration of the river Jelašnica watershed

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    Serbia’s hilly-mountainous regions are extremely vulnerable to flooding as a consequence of their natural characteristics and human impacts. Land mismanagement influences the development of erosion processes, and causes soil degradation that significantly reduces the land’s capacity to infiltrate and retain rainwater. Inappropriate land use as well as development activities replace permeable with impervious surfaces in the watershed. This leads to more rapid runoff generation and the more frequent appearance of torrential floods and bed-load deposits on downstream sections. Environmental degradation creates economicsocial problems within local societies which is often followed by depopulation. Restoring watersheds to their optimal hydrologic state would reduce flood discharge and by increasing groundwater recharge would increase both low-flow and average discharges in springs and streams. Best management practices could be developed through the application of specific combinations of biotechnical, technical and administrative measures, and by using the concept of ″natural reservoirs″. The design of such practices is explored through a case study of the watershed of the river Jelašnica, southeastern Serbia. Realization of these planned restoration works should help decrease the annual yields of erosive material by 44.1% and the specific annual transport of sediment through hydrographic network by 43.6%. Representative value of the coefficient of erosion will be reduced from Z=0.555 to Z=0.379. The value of maximal discharge Qmax-AMCIII (1%)=54.17 m3•s-1, before restoration, is decreased to Qmax-AMCIII (1%)=41.22 m3•s-1 after restoration, indicating the improvement of hydrological conditions, as a direct consequence of land use changes. Administrative measures are applied through ″Plans for announcement of erosive regions and protection from torrential floods in the territory of Leskovac municipality″

    Hydro-geological properties of the Savian aquifer in the county Obrenovac

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    The paper presents a description of hydrogeological researches of alluvial layers of the Sava River in the area of the source "Vić Bare" near Obrenovac. This source supplies groundwater to that town. The depth of these layers amounts to 25 m. With regard to collecting capacity, the most significant are gravel-sand sediments of high filtration properties. Their average depth amounts to about 13 m with the underlying layer made of Pleistocene clays. Compact aquifer is formed within these sediments and it refills partly from the Sava River at places where river cuts its channel into the gravel-sand layer. The analysis of the groundwater regime in the riparian area points out that groundwater levels follow stages of the Sava River. Such an influence lessens with the distance. Established hydraulic connection between the river and the aquifer enables its permanent replenishment. On the other hand, due to certain pollutions this river flow might bring along, it represents a potential danger. Those pollutions could enter water-bearing layer of the aquifer as well as the exploitation well of the source. Such presumptions have been confirmed in the experiment of pollution transport carried out in the water-bearing layer. Unabsorbable chloride was used as a tracer whose movement velocity through exploitation well proved that there were real possibilities of intrusion of aggressive pollutants into the water-bearing layer and into the aquifer as well. Therefore, the protection of the source must be in the function of the protection of surface waters

    Uticaj geološke podloge na oticaj

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    Runoff is the basic element of the water balance and phase of hydrological cycle influenced by numerous factors. The determination of the influence of certain factors on the runoff process can have strategic importance for planning and control of water resources. The study explores and presents the structure of the total runoff process, as well as the degree of possible influence of various geological terrains on the water runoff in natural conditions.Oticaj je osnovni element vodnog bilansa i faza hidrološkog ciklusa na koju utiču mnogobrojni faktori. Određivanje uticaja pojedinih faktora na proces oticaja može imati strateški značaj za planiranje i kontrolu vodnih resursa. U radu se izučava i prikazuje struktura procesa ukupnog oticaja, kao i stepena mogućeg uticaja različitih geoloških podloga na oticaj vode u prirodnim uslovima

    Water quality of the North Banat basal aquifer system

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    North Banat, an area of about 2329 km2 administered by six municipalities, is the extreme northeastern part of the Republic of Serbia and located in the southeastern margin of Pannonian depression. Drinking water is supplied under artesian or sub artesian pressure of Lower Pleistocene (Q1) or Upper Pliocene (Pl3) from confined aquifers. Tapped water-bearing beds in Banat dip from northeast to the south, reaching a depth of some 300 m at surrounding of Kikinda. Chemically, these 'uncommon' waters are a natural rarity controlled by geological and hydro geological characters of the water-bearing strata. The quality of water, periodically tested and examined, is discussed in this paper and its chemical composition is interpreted in terms of the regional geology

    Erosion control and protection from torrential floods in Serbia-spatial aspects

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    Torrential floods represent the most frequent phenomenon within the category of 'natural risks' in Serbia. The representative examples are the torrential floods on the experimental watersheds of the rivers Manastirica (June 1996) and Kamišna (May 2007). Hystorical maximal discharges (Qmaxh) were reconstructed by use of 'hydraulics flood traces' method. Computations of maximal discharges (Qmaxc), under hydrological conditions after the restoration of the watersheds, were performed by use of a synthetic unit hydrograph theory and Soil Conservation Service methodology. Area sediment yields and intensity of erosion processes were estimated on the basis of the 'Erosion Potential Method'. The actual state of erosion processes is represented by the coefficients of erosion Z=0.475 (Manastirica) and Z=0.470 (Kamišna). Restoration works have been planned with a view to decreasing yields of erosive material, increasing water infiltration capacity and reducing flood runoff. The planned state of erosion processes is represented by the coefficients of erosion Z=0.343 (Manastirica) and Z=0.385 (Kamišna). The effects of hydrological changes were estimated by the comparison of historical maximal discharges and computed maximal discharges (under the conditions after the planned restoration). The realisation of restoration works will help decrease annual yields of erosive material from Wa=24357 m3 to Wa=16198.0 m3 (Manastirica) and from Wa=19974 m3 to Wa=14434 m3 (Kamišna). The values of historical maximal discharges (QmaxhMan=154.9 m3·s-1; QmaxhKam=76.3 m3·s-1) were significantly decreased after the restoration (QmaxcMan=84.5 m3 ·s-1; QmaxcKam=43.7 m3·s-1), indicating the improvement of hydrological conditions, as a direct consequence of erosion and torrent control works. Integrated management involves biotechnical works on the watershed, technical works on the hydrographic network within a precisely defined administrative and spatial framework in order to achieve maximum security for people and their property and to meet other requirements such as: environmental protection, sustainable soil usage, drinking water supply, rural development, biodiversity sustaining, etc. The lowest and the most effective level is attained through PAERs (Plans for announcement of erosive regions) and PPTFs (Plans for protection from torrential floods), with HZs (Hazard zones) and TAs (Threatened areas) mapping on the basis of spatial analysis of important factors in torrential floods formation. Solutions defined through PAERs and PPTFs must be integrated into Spatial Plans at local and regional levels

    Erosion control and protection from torrential floods in Serbia-spatial aspects

    Get PDF
    Torrential floods represent the most frequent phenomenon within the category of “natural risks” in Serbia. The representative examples are the torrential floods on the experimental watersheds of the rivers Manastirica (June 1996) and Kamišna (May 2007). Hystorical maximal discharges (Qmaxh) were reconstructed by use of ″hydraulics flood traces″ method. Computations of maximal discharges (Qmaxc), under hydrological conditions after the restoration of the watersheds, were performed by use of a synthetic unit hydrograph theory and Soil Conservation Service methodology. Area sediment yields and intensity of erosion processes were estimated on the basis of the “Erosion Potential Method”. The actual state of erosion processes is represented by the coefficients of erosion Z=0.475 (Manastirica) and Z=0.470 (Kamišna). Restoration works have been planned with a view to decreasing yields of erosive material, increasing water infiltration capacity and reducing flood runoff. The planned state of erosion processes is represented by the coefficients of erosion Z=0.343 (Manastirica) and Z=0.385 (Kamišna). The effects of hydrological changes were estimated by the comparison of historical maximal discharges and computed maximal discharges (under the conditions after the planned restoration). The realisation of restoration works will help decrease annual yields of erosive material from Wа=24357 m3 to Wа=16198.0 m3 (Manastirica) and from Wа=19974 m3 to Wа=14434 m3 (Kamišna). The values of historical maximal discharges (QmaxhMan=154.9 m3•s-1; QmaxhKam=76.3 m3•s-1) were significantly decreased after the restoration (QmaxcMan=84.5 m3 •s-1; QmaxcKam=43.7 m3•s-1), indicating the improvement of hydrological conditions, as a direct consequence of erosion and torrent control works. Integrated management involves biotechnical works on the watershed, technical works on the hydrographic network within a precisely defined administrative and spatial framework in order to achieve maximum security for people and their property and to meet other requirements such as: environmental protection, sustainable soil usage, drinking water supply, rural development, biodiversity sustaining, etc. The lowest and the most effective level is attained through PAERs (Plans for announcement of erosive regions) and PPTFs (Plans for protection from torrential floods), with HZs (Hazard zones) and TAs (Threatened areas) mapping on the basis of spatial analysis of important factors in torrential floods formation. Solutions defined through PAERs and PPTFs must be integrated into Spatial Plans at local and regional levels

    Geological effect on the Grlište reservoir water quality

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    This work presents analytical data for copper (Cu), zinc (Zn) and manganese (Mn) of the Grlište storage reservoir that was built for water supply to Zaječar and the nearby communities. Because there was not any industry of military work that could be a source of heavy metals, the research focused on the geology of the area drained to the impounded lake. Occurrences and deposits of minerals in the area were registered and concentrations of copper, zinc and manganese in the lake analyzed and graphically represented. Water samples the analyses were taken at the upstream and downstream ends and the middle of the lake, each from three depths: lake surface, mid-depth and near the floor. Measurements spanned the period from 1991 to 2004. The copper and zinc concentrations had a gently rising trend in all sections, and manganese only in the upstream end of the lake
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