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The erosion potential model was applied to estimate the soil erosion status of rural settlements during the years 1971 and 2011. We used univariate and bivariate local Moran's I indices to detect and visualize the spatial clustering of settlements with respect to changes in erosion intensity and agricultural land use, as well as their mutual spatial correlation. The study area was differentiated into four statistically significant clusters using the calculated bivariate local Moran's I indices. The statistical analysis examined the two largest clusters, i.e., the high–high and low–low clusters, and the results of the research indicate that the first four principal components explained 70.50% and 73.47% of the total variance, respectively. In the high–high cluster, the low rates of erosion reduction (average Index Z = 98) in the most significant types of rural settlements were determined according to demographic indicators (i.e., the higher population vitality and population density, the smaller share of the old population and the lower average age of the population) and the large proportion of arable land and Neogene sediments. In the low–low cluster, high erosion reduction rates were detected (average index Z = 64). In this cluster, the more statistically significant influence of natural conditions in combination with demographic–agrarian processes (i.e., the larger share of the old population, the higher average age of the population, the lower vitality index and deagrarization) were decisive factors in changing erosion intensity. [ABSTRACT FROM AUTHOR]

In many Eastern European countries, the standard of living increased as a result of the process of industrialization in the second half of the 20th Century. Consequently, the population in rural areas with small-scale farming decreased due to the availability of employment elsewhere. This directly impacted soil erosion (and thereby sustainability of the land), but the degree and direction are not well known. This study investigates two municipalities within Serbia, their change in population and its impact on land use changes and soil erosion. The standard of living increased after the industrialization process in the 1960s within these municipalities. The erosion potential model is used to calculate gross annual erosion. The changes related to population and arable land in rural settlements are analyzed according to proportional spatial changes. The results show an overall decrease of erosion intensity in the study area. In addition, two basic findings are derived: first, the highest level of human impact on soil is in rural settlements at the lowest elevation zones, where erosion intensity shows the least amount of decrease; and, second, the most intensive depopulation process, recorded in higher elevation zones, indicates a rapid decrease of erosion intensity. [ABSTRACT FROM AUTHOR]

The study is concerned with determination of the trend of water discharge, suspended sediment concentration and sediment load in the most downstream profile of the Velika Morava River in the period 1967-2007. The gradual trend test (Mann-Kendall test - MK test) and abrupt change test (Pettitt test) have been employed on annual, seasonal and monthly water discharge, suspended sediment concentration and suspended sediment load for the given time series. Both the Mann-Kendall and Pettitt tests indicate that water discharge showed no significant annual trend or abrupt shift. However, annual suspended sediment concentration and sediment load showed significant decreasing trends (α=0.001). The average decrease of suspended sediment load transport amounted to 3.15 t/km2/yr. The Pettitt test results showed that the change-point year was detected in 1982. The average specific sediment load amounted to 134.6 t/km2/yr before the transition year, and 36.5 t/km2/yr after the transition year, i.e., it was reduced by 73 %. In the intra-annual distribution, the MK test results indicate that the most pronounced decreasing trend (α=0.001) of the sediment load is during summer and winter. Strong seasonal and monthly variability in sediment load was found. Sediment was strongly transported during spring months, in the period of frequent flood events. Almost 50% of the annual sediment is transported during March, April and May. Analysis of the discharge and suspended sediment concentration relationship revealed the existence of hysteresis loop in the shape of figure eight. The results of this study confirm the complex and heterogeneous nature of sediment response in the Velika Morava River. [ABSTRACT FROM AUTHOR]

Considering recent weather events in Serbia (especially the floods in 2014), a need has arisen for research that would help in identifying extreme weather phenomena. Therefore, the aim of this paper is to determine the thresholds above which intense precipitation can be considered as extreme precipitation events in Serbia. In this study, we determined the frequency of precipitation occurring at an intensity above the threshold of an extreme phenomenon (1961–2015), as well as the frequency of precipitation occurring at or above the absolute daily maximum in the reference period (1961–1990). The study sample included daily rainfall observations from 28 stations from the national meteorological network in Serbia. Applying a decile method, all the stations recording precipitation above the threshold of dangerous phenomena on the same day are classified into the corresponding decile. The threshold value was determined as the average value of the extreme annual precipitation in the analyzed period. The cases that are due to the high prevalence listed in the last decile are considered extreme. The results showed that the critical number of observation points above which an event is considered extreme precipitation event is 6.21, and a warning of the danger could be ensured only in the case of neighboring stations in the network. The threshold of extreme precipitation events for the individual stations ranges up to 130 mm. The obtained results might be used to mitigate the effects of extreme precipitation events in Serbia in the future. [ABSTRACT FROM AUTHOR]