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Central Europe and other parts of the world have experienced numerous extreme floods and prolonged periods of very low water discharges. With the increasing length and availability of hydrological data time series, it is now possible to analyse a larger volume of data. This paper presents long-term of changes in seasonal and maximum discharges. This paper aims to comprehensively assess the hydrological regime changes of Slovak rivers, using data from 26 gauging stations based on 90 years of observation. The study’s first part explores monthly flow changes within each year for selected Slovak rivers. The second part identifies changes in the maximum daily discharges, their long-term trends, and their occurrences. Additionally, we have compared the variability of the hydrological regime of the Slovak rivers with the variability of the hydrological regime of selected gauging stations on the Danube River and its tributaries, such as the Drava, Sajó, and Tisa rivers, to understand broader regional patterns. The findings show that the rivers selected exhibit relatively high intra-annual runoff variability, with various changes in the runoff regime curve based on the long-term monthly Pardé coefficient. For the Slovak region, maximum annual runoff variability is observed in the Krupinica and Plašťovce rivers (reaching a maximum of 12.1 during the period 1930–1960), while minimum annual runoff variability is observed in the Biely Váh River (2.205 for the period 1930–1960). The long-term trend analysis of the Burn index time series for maximum daily discharges over the entire period from 1930/31 to 2019/20, as well as the significance of trends during the summer-autumn and winter-spring seasons, shows that stations exhibited decreasing, stable, or increasing trends. The most significant increasing trend was observed at sixteen of the stations analyzed: at seventeen stations during the summer-autumn season and at nine stations during the winter-spring season over the period from 1930/31 to 2019/20.

Climate change is a global crisis exacerbated by human activity and a matter of urgent concern. There is a significant knowledge gap among primary school students in Serbia, as the topic of climate change is barely covered in the curriculum. This study examines their awareness, knowledge and attitudes. Of the participants, 96.6% are aware of climate change, but their knowledge and attitudes vary considerably. Some 80.10% expect climate change to have a significant impact on humans through floods (90%), droughts and temperature increases (85% each). Further results show that schools are a key source of information (35.10%), followed by television (30.10%) and the internet (14.90%). In summary, this study highlights the need for comprehensive, multidisciplinary climate education to address different levels of awareness, encourage informed and proactive responses and engage young voices in discussions about climate change.

This study reconstructs historical streamflow in the Sava River Basin (SRB), focusing on hydrological variability over extended timescales. Using a combination of Machine Learning (ML) and Deep Learning (DL) models, streamflow patterns were reconstructed from self-calibrated Palmer Drought Severity Index (scPDSI) proxies. The analysis included nine ML models and two DL architectures, with a post-prediction bias correction applied uniformly using the RQUANT method. Results indicate that ensemble methods, such as Random Forest and Gradient Boosted Tree, along with a six-layer DL model, effectively captured streamflow dynamics. Bias correction improved predictive consistency, particularly for models exhibiting greater initial variability, aligning predictions more closely with observed data. The findings reveal that the 2000–2022 period ranks as the lowest 23-year flow interval in the observed record and one of the driest over the past ~500 years, offering historical context for prolonged low-flow events in the region. This study demonstrates the value of integrating advanced computational methods with bias correction techniques to extend hydrological records and enhance the reliability of reconstructions. By addressing data limitations, this approach provides a foundation for supporting evidence-based water resource management in Southeastern Europe under changing climatic conditions. [ABSTRACT FROM AUTHOR]

For the trend analysis of the annual, seasonal and monthly precipitation linear regression and Mann-Kendall (MK) tests at the 5% significance level were applied. In this study, precipitation data from two stations in Serbia for the 1949-2019 period were used. Results indicate that increasing trends of precipitation for the selected station can be observed but these trends were not statistically significant according to MK test. Then again, MK test has shown that only on Palić station during autumn precipitations have statistically significant increase during the observed period with a p value of 0.0441 at the significant level p=0.005.

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.

This paper presents a comprehensive analysis of flood frequency and a spatio-temporal characterization of historical torrential floods in the Šumadija region using water discharge datasets and documented events. A chronology of 344 recorded torrential flood events, spanning from 1929 to 2020, illustrates the region's vulnerability, with a death toll exceeding 43. The study defines the intra-annual primary and secondary peaks of torrential flood occurrences and explains their spatial distribution. Furthermore, the identification of suitable probability distribution functions underscores the necessity of tailored approaches for effective flood risk management in this diverse geographical environment. The study employed Flood Frequency Analysis (FFA) and goodness-of-fit tests, including the Kolmogorov–Smirnov (K-S) and Cramér–von Mises (CvM) tests, to assess the frequency and magnitude of flood events and evaluate diverse distribution functions. The main results include the identification of suitable probability distribution functions for each river within the region, emphasizing the need for tailored approaches in flood risk management. Additionally, discharge values for various return periods offer crucial insights for informed decision-making in flood risk management and infrastructure planning. [ABSTRACT FROM AUTHOR]

The water quality and river discharges were surveyed at two sites in Nišava River basin (Dimitrovgrad and Niš) with complete data series for the ten-year period (2005-2014). For these stations SWQI was calculated and correlation analysis was applied. The index value is dimensionless and varies between 0 and 100 (best quality) It is derived from numerous physical, chemical, biological and microbiological parameters. At Niš station average annual value of SWQI is 78 (good) with a clear decrease trend over a ten-year period. On the other side, on Dimitrovgrad station, average annual SWQI is 89 (very good) with a clear positive trend. Goal of this paper was to determine if there is a correlation between river discharge and values of SWQI. Results of the Pearson correlation test between SWQI and daily discharge values for Dimitrovgrad station show a moderate linear relation was observed, r= -0.287, p = 0.002. On Niš station same test has shown that there is no statistically significant relation between discharge and water quality (r=0.103 p= 0.297). This study has shown that the correlation between SWQI and discharge is weak or not present at all at the investigated river.

Evaluative function of the final exam provides insight into the educational achievements of students and assessment of the degree of achievement of general and specific standards of achievement. When analyzing the results of students per school year (2013/2014, 2014/2015, 2015/2016 and 2016/2017) it is clear that in last two year, pupils approach to combined test, and geography questions has got more serious. The clear positive trend on total achieved percentage is noticed (y=4.9x+39.5). Same trend is noticed when results of each individual questions are analyzed. Even though our results show that boys achieved better results than girls, which is in contrast with state average, independent sample T-test results has shown that there is no statistically significant difference between results acquired by boys and girls. Although the final exam and the success of the elementary school are characterized by certain shortcomings, it is a good thing that they jointly contribute to the enrollment of students in high school because they compensate for their mutual shortcomings. However, it is important to make efforts to improve the quality of the assessment and the final exam, so that the education system is more equitable than it is currently.

This paper examines temporal and spatial variability and trends of annual and seasonal precipitation in Slovenia and their relationship with three atmospheric circulation patterns represented by their indices: North Atlantic Oscillation index (NAOi), Mediterranean Oscillation index (MOi) andWestern Mediterranean Oscillation index (WeMOi). Data from 45 precipitation stations were used for the period 1963–2012.Mean annual precipitation varies from 736 mm in eastern Slovenia to 2,518 mm in northwestern Slovenia. A significant annual precipitation decrease (from −3% to −6% per decade) is observed in western Slovenia. Significant negative trends are observed in southwestern Slovenia in summer (from −4% to −10% per decade) and near the Adriatic coast in spring (from −6% to −10% per decade). Non-significant negative and positive trends are observed in winter and autumn, respectively. Results indicate significant correlations between winter precipitation and MOi (from −0.3 to −0.7), NAOi (from −0.3 to −0.6) andWeMOi (from 0.3 to 0.6). Significant We-MOi influence is observed in spring and autumn, while NAOi and MOi influence has not been detected. Annual precipitation and WeMOi are significantly correlated in central and eastern Slovenia, while significant NAOi and MOi influence is observed in western Slovenia (with the larger area covered by MOi influence).

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.

The WQI method is most frequently used in expert and scientific research and basically it provides a mechanism for cumulative representation, numeric expression and defining a certain level of water quality. This paper aims to assess water quality of the Tisa River in Vojvodina (North Serbia) for the 2003 - 2012 period. Serbian Water Quality Index (SWQI) was used for assessment of the river water quality. WQI is expressed as a single value ranging from 0 to 100 (best quality) derived from numerous physical, chemical, biological and microbiological parameters. The results of SWQI for the Tisa River were mainly rated as good. Also, in this study it is noticed a clear decrease in water quality during warmer period of the year. Also, this study shows that water quality along the Tisa River decreases slightly but steadily down- stream, from Martonoš to Titel station and all along the length of the river provides values that according to SWQI descriptive quality indicator has been defined as good (72-83). The main problem of SWQI used in this paper is that it does not involve parameters of heavy metals concentration.

Due to negative demographic trends that primarily took hold of rural areas in the Republic of Serbia as early as at the end of the twentieth century - a decline in birth-rate and migrations from rural to urban areas, the question of ever growing number of combined classes and their organisation is being raised. Combined classes in schools do not represent a desirable model that should be aspired to in the organising of educational work in primary education. In fact it is a necessity and practical need in certain social rural areas. Combined classes are increasingly becoming a reality. Village schools make 60 percent of the total number of schools and are attended by only 8 percent of pupils. The larger number of grades a classroom teacher works with in a classroom, the more numerous teaching organisation problems there are. The Educational Strategy of the Republic of Serbia 2011-2120 says that small village schools should be saved since their number will increase in the coming years considering demographic trends. This paper depicts main didactic problems that occur in the process of simultaneous work with students of different ages, in the same room, by one class teacher, as well as the possibility of their solution. Methods used in this paper include theoretical analysis of the existing literature as well as conversations with primary school teachers who teach combined classes.

The river Danube belongs to the Black Sea basin and it flows through ten European countries. It also flows through 35 larger cities including Novi Sad in Serbia. The water quality of the Danube is one of significant factors that are taken into consideration in evaluation of sustainability of the development of this region and it is controlled by complex anthropogenic activities and natural factors. With the assistance of correlation analysis, the paper studied the impact of natural factors such as water temperature, air temperature and precipitation rate on certain parameters indicating the water quality. Based on the results of the study it has been determined that natural factors affect changes in water quality throughout the year and that water temperature affects most the concentration of nitrogen oxide.

A Water Quality Index (WQI) is a numeric expression used to evaluate the quality of water bodies and make it easier understood by managers. This paper aims to assess water quality of Sava River in Vojvo­dina (North Serbia) for the 2004 - 2011 period. For this purpose authors applied: Serbian Water Qual­ity Index (SWQI) assessment. WQI value is dimensionless, single number ranging from 0 to 100 (best quality) derived from numerous physical, chemical, biological and microbiological parameters. For the Sava River SWQI was mainly rated as very good. This study shows a clear decrease in water quality dur­ing warmer periods of the year. Additionally, this study shows that water quality along Sava River de­creases slightly downstream, of Sremska Mitrovica station but it still provides values that according to SWQI descriptive quality indicator have been defined as good (72-83) and very good (84 - 89). Also, this study shows an increase of SWQI downstream of the confluence of Drina River into Sava River. This methodology includes parameters for assessment of organic loading, but does not involve parameters of heavy metals concentration.

The focus of this research is Special nature reserve Carska bara that is situated in the area of central Banat (Vojvodina, Serbia). The whole territory of the Reserve and the surrounding area represents space that has been under the influence of human activities since the very beginning of the development of human communities. Another great influence comes from the process of melioration of the whole area and mainly of the river Begej, which consequently results in changes in sediments and their quality. Sediment has a strong influence on numerous goals and functions of protection. It changes the characteristics of the landscape and ecosystems. That is why the process of sediment remediation, through the process of demudding, is of crucial importance for the protection of this area and its natural values. Remediation influences some important aims of managing the area such as nature protection, education and tourism.

A direct consequence of the global climate change is the alteration of seasonal precipitation patterns and as a consequences pluvial flood in urban areas becoming more frequent. In this study, precipitation patterns for the city of Novi Sad were analysed for the 1961-2020 period. For the extraction of extreme precipitation values, the peaks-over-threshold method was applied with the threshold level set at the 90th percentile. For the inspection of time-dependent occurrence rates and assessment of significant changes, a Kernel estimation was applied. For the assessment of the significances of the occurrence rate estimation Cox-Lewis (CL) test was used. The obtained results indicate decreasing trends in occurrence rate and frequency of minor and strong events in the second half of the 20th century. On the other hand, we argue that there is the increase of occurrence rate and frequency of extreme events at the beginning of the new millennia. Regarding the occurrence and frequency of the extreme events a clear increase in occurrence rate and frequency can be observed, especially when frequency is observed as from the year 2000 a total of 11 of these extreme years occurred in contrast to six events prior 2000. The application of the CL test yields a decreasing trend of strong events and increasing trend of extreme events. The p values are as small as 0.0336 and 0.0034 respectively. The test confirms what confidence bands display, i.e., more and more extreme participations per decade towards the modern times. [ABSTRACT FROM AUTHOR]

The article titled "Water Resources Management: Methods, Applications and Challenges" is a comprehensive monograph that provides insights into various aspects of water resources management. It covers topics such as the impact of climate change on river discharge, flood exposure in Serbia, water quality concerns in the Volga River Basin, and the ecological consequences of abandoned hydropower projects. The monograph offers valuable information for scholars, policymakers, and practitioners in the field of water resources management. It emphasizes the need for proactive measures to address climate change, water pollution, and sustainable water resource utilization. [Extracted from the article]

The main aim of the research was to determine teachers' opinion on the importance of teaching equipment in geography classroom. The research was conducted during the school year 2020/2021. A total of 134 geography teachers from different districts in Serbia took part in the survey. In general, 57.5% of the participants stated that their school buildings have a specialized and separate geography classroom, while in other schools a classroom is shared between related subjects. It is interesting that 84.3% of the participants stated that in their classrooms they have internet at their disposal. Further, it was concluded that there is no statistically significant correlation between the availability of internet connection and the location of school (rural and urban). On the other hand, one of the biggest problems that 38.8% of the participants highlighted is that maps, which are essential for geography teaching, are approximately 20 years old. On average, the best grade for equipment is awarded to schools in the City of Belgrade (3.47) while the lowest grade is awarded to geography classrooms in Kosovo and Metohija province (2.00). On average, participants graded that their classroom equipment is "good" (3.02) while the importance of classroom equipment was graded with "very good" (4.49). [ABSTRACT FROM AUTHOR]

Drought is a natural phenomenon that occurs when the availability of water is significantly below the normal levels during a shorter or longer period of time and cannot meet the necessary demand. This study focused on hydrological drought assessment of the Tisza River on four gauging stations: Vásárosnamény, Szolnok, Szeged, and Senta for the period 1964-2018. An effective Streamflow Drought Index (SDI) has been recently proposed and widely used for determining hydrological droughts. Both long- and short-term droughts have very severe impacts on the investigated locations. Two drought periods can be singled out: the first period was from 1983 to 1993, with the exceptions in 1985 and 1987. This period is characterized by higher absolute SDI values on Vásárosnamény (-0.84) and Szolnok (-0.87) than on Szeged (-0.29) and Senta (-0.40) stations. The second period was more severe and lasted from 2011 to 2015, with an average SDI value of -1.32 on Vásárosnamény, -1.08 on Szolnok, -0.53 on Szeged, and -0.57 on Senta station. The Mann-Kendall test results indicate that there is no trend indicating transition from humid towards more arid condition over the investigated period. [ABSTRACT FROM AUTHOR]

Droughts are natural hazards that endanger the safety of population, their property and can create serious agricultural and ecological problems over the affected region. An analysis of the Standardized Precipitation Index (SPI) was performed by using the database of sixty years (1956-2016) of the monthly precipitation for the nine meteorological stations in Vojvodina region (Serbia). The SPI has been used for drought determination. The present study investigates the application of k-means clustering methods on the SPI at the 12-month timescale values to detect distinct drought clusters. For the purpose of determining the optimal number of clusters, the Gap Statistics was used. The results show that the total of four clusters (regions) can be identified in Vojvodina: three stations are listed in region 1 (Sombor, Palić, and Novi Sad), two stations in region 2 (Bač and Sremska Mitrovica), region 3 is a single-station region (Bela Crkva), while in region 4, three stations are grouped (Kikinda, Zrenjanin, and Vršac). The Mann-Kendall test has shown that only in region 1 there is a trend in SPI values ranging from arid towards more humid conditions in the 1956-2016 period. In other regions no trend was observed in the data series. These results could contribute to water resources and agricultural planning and management in Vojvodina region and also confirm the usefulness of clustering methods for drought regionalization. [ABSTRACT FROM AUTHOR]