Stevan Prohaska

Institut za vodoprivredu "Jaroslav Černi"

This study highlights significant recent increases in water and air temperatures in the rapidly developing city of Belgrade, Serbia to raise awareness of the anticipated negative impacts and the urgent need to develop appropriate mitigation strategies. We investigate the mean annual water temperature trends at the confluence of the Sava and Danube...

This study analyzed the annual and low-flow trends of rivers located in Serbia, a part of southeast Europe. To achieve this, a comprehensive framework for flow trend estimation was established using both the conventional Mann–Kendall trend test and its modified version, which considers the serial correlation of flows, alongside the Theil-Sen trend...

Climate change is presently a widely discussed subject in relation to alterations in water storage capacity and the components of the hydrological balance within catchment areas. This research study was directed at two main objectives: 1. The indirect estimation of long-term mean annual runoff using an empirical model; 2. The determination of chang...

In confluence areas, where river flow slowdowns can be substantial, the selection of design flows for the purpose of designing a flood control system directly depends on flood waves at the mainstem and its tributaries. The aim of this paper is twofold: to elaborate a procedure that will define the flood exceedance probability in the analyzed area w...

The long-term runoff variability is identified to consist of the selected large rivers with long-term data series in the Danube River Basin. The rivers were selected in different regions of the Danube River Basin and have a large basin area (Danube: Bratislava gauge with 131,338 km2; Tisza: Senta with 141,715 km2; and Sava: Sremska Mitrovica with 8...

Data on historic floods along the Danube River exist since the year 1012. In the Middle Ages, floods were estimated based on historical documents, including original handwritten notes, newspaper articles, chronicles, formal letters, books, maps and photographs. From 1500 until the beginning of organized water regime observations, floods were hydrau...

Climate change projections of precipitation and temperature suggest that Serbia could be one of the most affected regions in southeastern Europe. To prepare adaptation measures, the impact of climate changes on water resources needs to be assessed. Pilot research is carried out for the Lim River basin, in southeastern Europe, to predict monthly flo...

The paper deals with the determination of theoretical hydrographs of the Drava floods at the Donji Miholjac hydrological station profile. The applied procedure is based on a recent comprehensive approach which simultaneously considers two basic flood hydrograph parameters - maximum hydrograph ordinate (peak) and flood wave volume. The elaborated pr...

In this paper the estimation of high return period quantiles of the flood peak and volume in the Kolubara River basin are carried out. Estimation of flood frequencies is carried out on a data set containing high outliers which are identified by the Rosner's test. Simultaneously, low outliers are determined by the multiple Grubbs-Beck (MGB). The nex...

The short-term predictions of annual and seasonal discharge derived by a modified TIPS (Tendency, Intermittency, Periodicity and Stochasticity) methodology are presented in this paper. The TIPS method (Yevjevich 1984) is modified in such a way that annual time scale is used instead of daily. The reason of extracting a seasonal component from discha...

The authors propose a new approach for trend assessment that takes into account long-term periodicity of annual flows. In particular, analysis is performed of annual flows recorded at the locations of 30 operating and designed hydropower plants (HPPs) in Serbia, in order to assess the current and future water availability for hydropower generation....

The authors present a detailed procedure for modelling of mean monthly flow time-series using records of the Great Morava River (Serbia). The proposed procedure overcomes a major challenge of other available methods by disaggregating the time series in order to capture the main properties of the hydrologic process in both long-run and short-run. Th...

In present paper we develop a model of monthly river flow rate using artificial neural networks, based on the assumption that air temperature and precipitation predetermine the flow rate dynamics. In order to create a reliable prediction model, we used monthly observations made at Lim river basin in southwestern Serbia from 1950 to 2012, since resu...

The aim of the paper is to study spatial and temporal changes in the magnitude, duration and frequency of high flows in the Danube basin. A hydrological series of the mean daily discharges from 20 gauging stations (operated minimally since 1930) were used for the analysis of changes in the daily discharges. The high flow events were classified into...

In the present paper we propose a new model of monthly river flow rate as a simple nonlinear function of air temperature and rainfall. Response surface methodology is used to analyze the observed monthly flow rates from 1950 to 1990 for Great Morava River, as the largest domestic river in Serbia. Obtained results indicate significant linear and qua...

The paper presents a theoretical basis for defining the coincidence of flood waves in the zone of significant interaction between the mainstem and its tributary. It shows the mathematical bases and procedures for defining the lines of same probabilities of occurrence and the lines of probabilities of exceedance for two random variables. In the case...

Water resource has become a guarantee for sustainable development on both local and global scales. Exploiting water resources involves development of hydrological models for water management planning. In this paper we present a new stochastic model for generation of mean annul flows. The model is based on historical characteristics of time series o...

Global warming affects the hydrological cycle and the long-term water budget of river basins. Flow variations have been noticed in the Danube River Basin, especially in its south-western parts where a downward trend in mean annual flows has been prevalent in the past several decades. Time series of mean annual and seasonal flows of the Sava River a...

The internal structure of hydrologic processes is discussed in the paper. Time series of mean annual river discharges are assessed to determine their stationarity, trend and periodicity. The time series of annual discharges are determined to be non-stationary. The trend varies in different time segments, with changing trend intensity and directi...

In the absence of detailed exploration of karstic catchments, the calculation of available reserves and elements of the water balance equation frequently reflect the topographic size of the catchment area, and not the actual, active (underground) size. Te two differ largely where karst is concerned. Te paper deals with the problem of average catchm...

The process of flood waves formation in complex river systems, such as the confluence of significant tributaries on the relatively short sector on a main water course, is very complicated, both from the standpoint of flood wave genesis of the mainstream and tributaries, and from the standpoint of selection of design flood flow for the flood control...

The flood coincidence methodology within this contribution gives a statistically sound analysis concerning an important feature of flood genesis. The whole Danube reach is covered by such research, which reveals flood behaviour along the Danube impressively. The practical results could serve as a tool for experts and decision-makers, and aid in det...

The quality of karst groundwater is generally high and does not require substantial investment in treatment to raise it to drinking water standards. However, from a hydrologic perspective, karst groundwater resources are the least researched of all water resources and hydro-meteorological services do not devote sufficient attention to them. This pa...

Based on a recent research of floods and droughts in Serbia, this paper will deal with interrelation of both extreme floods and hydrologic droughts. Territory of the Republic of Serbia is analyzed area, excluding the Province of Kosovo and Metohija. Gage stations, that control areas of catchments from 84 km² (Donja Satornja GS on the Jasenica River...

The aim of the presented research is improvement of methodology for probability calculation of coinciding occurrence of historic floods and droughts in the same year. The original procedure was developed in order to determine the occurrence probability of such an extreme historic event. There are two phases in calculation procedure for assessment o...

When providing hydrologic indicators needed for hydro power plant design, knowledge of mean monthly flows allows for estimation of majority of indicators. The paper deals with a problem of obtaining mean monthly flows at the location where flow observation data do not exist. The closest gauge station from the observation network is selected as an a...

River flooding in Serbia is a natural phenomenon which largely exceeds the scope of water management and hydraulic engineering, and has considerable impact on the development of Serbian society. Today, the importance and value of areas threatened by floods are among the key considerations of sustainable development. As a result, flood protection te...

This paper addresses the definition of multiple coincidences of flood waves on the main river and its tributaries. Contrary to previous studies of partial coincidences of various flood parameters (Prohaska 1999) for the main river and one of its tributaries, this procedure allows for the definition of complex (multiple) coincidences of a single par...

The paper examines flood wave genesis in a portion of a river basin under conditions which involve considerable spatial and temporal variation of river flow. A procedure is presented for the definition of hydrograph components for the considered portion of the river basin for different probabilities of occurrence. High-flow coincidence functions ar...

This paper describes a mathematical model for evaluation of risk, to which engineering structures and valuable assets are exposed. Considerations presented hereafter rely upon the commonly applied probabilistic concept used to select design flood having return period T, or exceedance probability of p=1/T, which are routinely calculated in many desi...

This paper presents the main results of application of mathematical model VNC for evaluating river discharge in terms of climate change. The theoretical basis for the model VNC will be given in the paper as well as its results applied to the Nišava river cathcment in Serbia. The input parameters are estimates of changes of the basic meteorological...

As floods and droughts are normal, recurrent features in climate, this paper will present an introduction to an in-depth analysis of draught and flood interrelation on rivers in Serbia. There are 144 gauge stations flow data available for analysis. These stations form an observation network of Hydro-Meteorological Service of the Republic of Serbia....