Spatial distribution of specific runoff in Serbia based on rainfall-runoff relationship

One of the indicators of water potential and water resources is specific runoff. Specific runoff for the whole territory of Serbia was obtained using the exponential relation between depth of runoff Y (mm) and precipitation P (mm). This relation is obtained on the basis of the mean annual amount of precipitation and annual water discharge, namely the depth of the runoff for 69 basins for the period 1961–2010. Coefficient of determination (R²) of relation between the depth of runoff and precipitation is 0.72. The differences between measured and modeled values of specific runoff vary from basin to basin, but at the level of the whole Serbia it is 3.5%. More precisely, the measured specific runoff amounts 5.6 l/s/km2, and the modeled specific runoff is 5.7 l/s/km2. The verification was done by applying the model to 11 large river basins in Serbia. Spatial distribution of the modeled specific runoff is presented by a digital map of specific runoff with pixel resolution 100 × 100 m which enables the estimation of mean annual water discharge in any ungauged basin in Serbia

Danube River discharge at Bezdan gauging station (Serbia) and its correlation with atmospheric circulation patterns

For understanding hydroclimatological process chain it is crucial to identify relations between large-scale climatic circulations and river discharge. The Danube is one of the most important European waterways, flowing 2.857 kilometers across the Europe and with 817.000 km2 basin. Danube River average and maximum discharges are correlated with eight atmospheric circulation patterns indices: AOi, EAi, EA/WRi, ENSOi, MOi, NAOi, SCANDi and WeMOi in 65 years period at the Bezdan gauging station in Serbia. Obtained results showed that precipitation, MOi and WeMOi have constant and dominant influences on Danube River average discharge at Bezdan gauging station, while maximum discharge is mainly influenced by precipitation and MOi. All registered correlations are positive

Analysis of seasonal flow and minimum water discharge of Veliki Rzav for the purposes of regional water supply system "Rzav"

Minimum water discharge and seasonal flow calculations of Veliki Rzav at Arilje have been conducted for the purposes of regional water supply system "Rzav". For the first time for this hydrological station minimum water discharges have been calculated by frequency curves, parameters of which have been determined by method of moments. Also for the first time in Serbia seasonal flow was calculated using "composing method". Analysis presented in this paper can be used for exploitation and planning of upcoming water management activities in the regional water supply system "Rzav

Water quality in the Golijska Moravica basin

The basin of the Golijska Moravica River is rich in water, and therefore its water is used for water supply of towns and industry not only in the basin but in the whole region as well. This paper presents the status of water quality in the main rivers of the basin, and recommends measures for water quality protection

Trends of mean annual and seasonal discharges of rivers in Serbia

Subjects of this paper are trends of annual and seasonal water discharges in Serbia. Data of water discharges at the 94 hydrological stations in the period 1961-2010 were analyzed, using the Mann-Kendall test and Sen's method. It was concluded that 27% of analyzed stations have statistically significant changes on annual level and 14-24% on seasonal level. The annual, winter, spring and summer trends are negative, while positive trends occur at only one station for annual values, on many stations in autumn and at a small number of stations in winter. Considering the quality of data, the results of the Beli Drim River basin require additional research, while negative trends at stations downstream of water reservoirs, primarily in basins of Južna Morava and Drina rivers, are consequences of human activities. Results show that the attention of the competent water management authorities should be directed to the Timok and Južna Morava basins in terms of the expected decrease of amounts of water, and to the basins of Toplica, Nišava, Pusta, Ibar and Kolubara rivers when it comes to increase of amounts of water. [Projekat Ministarstva nauke Republike Srbije, br. 47007

Use of the RHS method in Golijska Moravica river basin

River Habitat Survey (RHS) is terrain method developed in UK in 1994. for determination of physical character of rivers and river basin. This method is applied for the first time in Golijska Moravica river basin. Two indices which broadly describe the diversity of river habitat and landscape features (Habitat Quality Assessment (HQA)) and extent and severity of artificial modification to the channel (Habitat Modification Class (HMC)) has been developed for reporting purposes. These are based on simple scoring systems which have been agreed by technical experts

Hydrological droughts in the Južna Moravia river basin (Serbia)

Spatial and temporal analysis of hydrological droughts, defined by two variables: deficit and duration of drought, is presented in this paper. Time series of deficits and drought durations are derived using threshold level method for 15 hydrological stations in basin of Južna Morava (Serbia). Since Q90 was used as threshold level for drought definition, these time series are ready for frequency analysis of extreme droughts. The longest average duration of drought is observed on Visočica River at Braćevci, then on Vlasina River at Vlasotince, and shortest droughts on upstream stations of Južna Morava, Vladičin Han and Grdelica. There is a direct relationship between absolute values of drought deficits and catchment area or mean annual water discharge, while standardize deficits have similar spatial distribution as drought duration. Regional deficit index (RDI) was calculated, which enabled insight in spatial-temporal drought characteristics in defined regions, like seasons when droughts most often occur, and derivation of largest droughts, both in terms of their duration, and covered area

DataSheet1_Variation in the VLF signal noise amplitude during the period of intense seismic activity in Central Italy from 25 October to 3 November 2016.PDF

Recent research shows reductions in the VLF signal noise amplitude that begin before particular earthquakes whose epicentres are more than 100 km away from the signal propagation path. In this paper, we extend this research to studying the noise amplitude during periods of intense seismic activity in a localized area. We analyse variations in the VLF signal noise amplitude over a period of 10 days (25 October–3 November 2016) when 981 earthquakes with the minimum magnitude of 2 occurred in Central Italy. Out of these events, 31 had the magnitude equal or greater than 4, while the strongest one had the magnitude of 6.5. We observe the VLF signal emitted by the ICV transmitter located in Sardinia (Italy) and recorded in Belgrade (Serbia). Bearing in mind that the trajectory of this signal crosses the area in which the observed earthquakes occurred, we extend the existing research to study of variations in the noise amplitude of the signal propagating at short distances from the epicentres of the considered earthquakes. In addition, we analyse the impact of a large number earthquakes on characteristics of the noise amplitude and its reductions before particular events. In order to examine the localization of the recorded changes, we additionally analysed the noise amplitude of two reference signals emitted in Germany and Norway. The obtained results show the existence of the noise amplitude reduction preceding individual strong or relatively strong earthquakes, and earthquakes followed by others that occurred in a shorter time interval. However, the additional noise amplitude reductions are either not pronounced or they do not exist before the considered events in periods of the reduced noise amplitude remain from previous earthquakes. Reductions in noise amplitudes for all observed signals indicate a larger perturbed area through which they spread or its closer location to the receiver. The analysis of daily values of parameters describing the noise amplitude reveals their variations start up to 2 weeks before the seismically active period occurs.</p

Lessons from the 2018-2019 European droughts: a collective need for unifying drought risk management

Drought events and their impacts vary spatially and temporally due to diverse pedo-climatic and hydrologic conditions, as well as variations in exposure and vulnerability, such as demographics and response actions. While hazard severity and frequency of past drought events have been studied in detail, little is known about the effect of drought management strategies on the actual impacts and how the hazard is perceived by relevant stakeholders. In a continental study, we characterised and assessed the impacts and the perceptions of two recent drought events (2018 and 2019) in Europe and examined the relationship between management strategies and drought perception, hazard, and impact. The study was based on a pan-European survey involving national representatives from 28 countries and relevant stakeholders responding to a standard questionnaire. The survey focused on collecting information on stakeholders' perceptions of drought, impacts on water resources and beyond, water availability, and current drought management strategies on national and regional scales. The survey results were compared with the actual drought hazard information registered by the European Drought Observatory (EDO) for 2018 and 2019. The results highlighted high diversity in drought perception across different countries and in values of the implemented drought management strategies to alleviate impacts by increasing national and sub-national awareness and resilience. The study identifies an urgent need to further reduce drought impacts by constructing and implementing a European macro-level drought governance approach, such as a directive, which would strengthen national drought management and mitigate damage to human and natural assets