Flood management of lowland rivers in the stream of the Danube riverthrough Serbia

Doktorska disertacija razrađuje metodologiju izrade modela upravljanja poplavama na velikim ravničarskim rekama korišćenjem preciznih digitalnih modela terena (DTM) i kombinacije 1D/2D hidrauličkih modela nestacionarnog tečenja. Za razradu modela korišćena je reka Dunav na teritoriji Srbije sa svojim pritokama. Dužina hidrauličkog modela je 715 km i postignuta tačnost modela, poređenjem izračunatih i izmerenih nivoa na devet vodomernih stanica, je ispod 10 cm. Dosadašnja strategija odbrane od poplava na velikim rekama, kao što je Dunav, bazirala se na "pasivnim merama" izgradnje nasipa i kejskih zidova. U radu je prikazana mogućnost primene nove strategije upravljanjem poplavnog talasa preko uređenih retenzija. Rezultati disertacije su omogućili i rekonstrukciju poplavnog talasa iz 1965. g.The dissertation elaborates a methodology for flood management model on large lowland rivers using precision digital terrain models (DTM) and combined 1D/2D unsteady flow model. For the development of the model, the river Danube on the territory of Serbia was used with its tributaries. The length of the hydraulic model is 715 km and the achieved accuracy of the model, by comparing the calculated and observed levels on 10 water stations, is below 10 cm. Оur current defense against floods in big lowland rivers is relied on passive defence with building and overhanging existing levees and walls. In dissertation is shown the possibility of applying a new strategies of flood management with retentions. The results of the dissertation also enabled the reconstruction of the 1965. flood wave

River Floodplain 1D/2D Hydraulic Modelling Combined with Recent LiDAR DTM Technology

The study presents problem of floods management for lowland rivers and provides solution for such complex task. The paper aims to elaborate a methodology for flood management model on large lowland rivers using precision digital terrain models (DTM) and combined 1D/2D unsteady flow model. The river Danube on the territory of Serbia was used with its tributaries for the development of the model. The length of the hydraulic model is 715 km and the achieved accuracy of the model, by comparing the calculated and observed levels on 10 water stations, is below 10 cm. Combined 1D/2D HEC-RAS model is adjusted by making use of the resulting high-resolution input. The ability of the combined 1D/2D model, based mainly on the high-accuracy input data, provides an accurate estimate of flood wave propagation. The result of this paper is a defined methodology providing sufficient accuracy to the hydraulic model of flood wave propagation in case of large lowland rivers, requiring acceptable short calculation time. Also, the methodology to specify relevant flood stage (design flood) which is used to determine levee crest elevation is developed in this paper

A Methodology Proposal for Selecting the Optimal Location for Small Hydropower Plants

The hydropower potential in the Republic of Serbia, as the most important renewable energy source, has been estimated at around 17000 GW·h per year, where approximately 2000 GW·h could be obtained from small hydropower plants (SHP). Small hydropower plants in Serbia currently produce 150 GW·h. Accordingly, the share of the electricity production from small hydropower plants in the total electricity production in Serbia is too small. The paper presents a model for the selection of optimal locations for small hydropower plants, which includes an ecological criterion, along with technical and economic criteria. The ecological criterion is eliminatory, i.e. those parts of the watercourse that border on or pass through protected natural assets are not taken into account when considering potential optimal locations for SHPs. All technical and economic criteria are included in the calculation of the weighted arithmetic mean with the aim of determining the optimal position for the construction of small hydropower plants. The model is implemented in the SHPOP software and its application is demonstrated on five watercourses in Southeastern Serbia

The Influence of Temperature Changes on Concrete Pavement

The paper deals with the influence of temperature changes on concrete pavement. Due to differences in temperature on the upper and the lower surface of a concrete slab, the bending stress is created, resulting in concrete slab deformation. During the process of heating, the difference in temperature between the upper and the lower surface of pavement is created as a result of heat conduction. The upper surface has a tendency to expand (tense), whereas the lower one does not alter its dimensions, which results in generating the bending stress. Concrete pavement is most commonly placed in zones with extremely heavy traffic load as well as at bus stops. The analysis was carried out at bus stops in the city of Novi Sad for three different types of slab thickness. The thickness of slabs was 20, 22 and 24 cm. The testing was conducted in the longitudinal and transverse direction of the concrete pavement, both in the middle and on the edge of a slab. During the analysis of results, a conclusion was drawn that the concrete slabs were of different dimensions and thickness, and that they were placed on different subgrade reactions. The maximum values of stress were recorded in the middle of a concrete slab, in slabs whose thickness amounted to 24 cm, while the minimum stresses were identified in slabs which were 20 cm thick. The paper presents the stresses of concrete slabs, caused by changes in temperature, which depend on the subgrade reaction and dimensions of concrete slabs

Flood management of lowland rivers in the stream of the Danube riverthrough Serbia

Doktorska disertacija razrađuje metodologiju izrade modela upravljanja poplavama na velikim ravničarskim rekama korišćenjem preciznih digitalnih modela terena (DTM) i kombinacije 1D/2D hidrauličkih modela nestacionarnog tečenja. Za razradu modela korišćena je reka Dunav na teritoriji Srbije sa svojim pritokama. Dužina hidrauličkog modela je 715 km i postignuta tačnost modela, poređenjem izračunatih i izmerenih nivoa na devet vodomernih stanica, je ispod 10 cm. Dosadašnja strategija odbrane od poplava na velikim rekama, kao što je Dunav, bazirala se na "pasivnim merama" izgradnje nasipa i kejskih zidova. U radu je prikazana mogućnost primene nove strategije upravljanjem poplavnog talasa preko uređenih retenzija. Rezultati disertacije su omogućili i rekonstrukciju poplavnog talasa iz 1965. g.The dissertation elaborates a methodology for flood management model on large lowland rivers using precision digital terrain models (DTM) and combined 1D/2D unsteady flow model. For the development of the model, the river Danube on the territory of Serbia was used with its tributaries. The length of the hydraulic model is 715 km and the achieved accuracy of the model, by comparing the calculated and observed levels on 10 water stations, is below 10 cm. Оur current defense against floods in big lowland rivers is relied on passive defence with building and overhanging existing levees and walls. In dissertation is shown the possibility of applying a new strategies of flood management with retentions. The results of the dissertation also enabled the reconstruction of the 1965. flood wave

Flood management of lowland rivers in the stream of the Danube riverthrough Serbia

Doktorska disertacija razrađuje metodologiju izrade modela upravljanja poplavama na velikim ravničarskim rekama korišćenjem preciznih digitalnih modela terena (DTM) i kombinacije 1D/2D hidrauličkih modela nestacionarnog tečenja. Za razradu modela korišćena je reka Dunav na teritoriji Srbije sa svojim pritokama. Dužina hidrauličkog modela je 715 km i postignuta tačnost modela, poređenjem izračunatih i izmerenih nivoa na devet vodomernih stanica, je ispod 10 cm. Dosadašnja strategija odbrane od poplava na velikim rekama, kao što je Dunav, bazirala se na "pasivnim merama" izgradnje nasipa i kejskih zidova. U radu je prikazana mogućnost primene nove strategije upravljanjem poplavnog talasa preko uređenih retenzija. Rezultati disertacije su omogućili i rekonstrukciju poplavnog talasa iz 1965. g.The dissertation elaborates a methodology for flood management model on large lowland rivers using precision digital terrain models (DTM) and combined 1D/2D unsteady flow model. For the development of the model, the river Danube on the territory of Serbia was used with its tributaries. The length of the hydraulic model is 715 km and the achieved accuracy of the model, by comparing the calculated and observed levels on 10 water stations, is below 10 cm. Оur current defense against floods in big lowland rivers is relied on passive defence with building and overhanging existing levees and walls. In dissertation is shown the possibility of applying a new strategies of flood management with retentions. The results of the dissertation also enabled the reconstruction of the 1965. flood wave

Effects of reactive filters based on modified zeolite in dairy industry wastewater treatment process

Application of adsorbents based on organo-zeolites has certain advantages over conventional methods applied in food industry wastewater treatment process. The case study presented in this paper examines the possibilities and effects of treatment of dairy industry wastewater by using adsorbents based on organo-zeolites. The obtained results indicate favorable filtration properties of organo-zeolite, their high level of adsorption of organic matter and nitrate nitrogen in the analyzed wastewater. This paper concludes with recommendations of optimal technical and technological parameters for the application of these filters in practice

Mountain Road-Culvert Maintenance Algorithm

The objective of this research was to determine the probability of road overtopping occurrence for a road culvert caused by surface runoff from the upstream catchment. A hydrological–hydraulic model was used for the development of an algorithm for road culvert maintenance based on the overtopping occurrence probability (CMOOP algorithm) for small mountain catchments. The hydrological model defines the regression dependence between the runoff hydrograph peak values and the probability of occurrences, whereas the hydraulic model calculates the culvert flow capacity by including in the calculation the level of sediment that culvert is filled with. The relationship between occurrences of overtopping and peak runoff value was defined using the runoff hydrograph transformation model in the accumulation on the upstream side of the road. In addition to the calculation of overtopping occurrence probability for the existing culvert condition, the CMOOP algorithm was used to analyze the impact of rehabilitation and reconstruction works from the perspective of legally based safety criterion for road overtopping occurrence probability (SCROOP). The CMOOP algorithm was appled to 67 concrete culverts located in a mountain road section in the Republic of Serbia. The results show that the application of rehabilitation works on selected culverts will increase the percentage of culverts that satisfy SCROOP from 49.25% to 89.55%, which confirms that the accumulated stone sediment is the main reason for the SCROOP unfulfillment

Exploitation of Documented Historical Floods for Achieving Better Flood Defense

Establishing Base Flood Elevation for a stream network corresponding to a big catchment is feasible by interdisciplinary approach, involving stochastic hydrology, river hydraulics, and computer aided simulations. A numerical model calibrated by historical floods has been exploited in this study. The short presentation of the catchment of the Tisza River in this paper is followed by the overview of historical floods which hit the region in the documented period of 130 years. Several well documented historical floods provided opportunity for the calibration of the chosen numerical model. Once established, the model could be used for investigation of different extreme flood scenarios and to establish the Base Flood Elevation. The calibration has shown that the coefficient of friction in case of the Tisza River is dependent both on the actual water level and on the preceding flood events. The effect of flood plain maintenance as well as the activation of six potential detention ponds on flood mitigation has been examined. Furthermore, the expected maximum water levels have also been determined for the case if the ever observed biggest 1888 flood hit the region again. The investigated cases of flood superposition highlighted the impact of tributary Maros on flood mitigation along the Tisza River