Changes in Soil Erosion Intensity Caused by Land Use and Demographic Changes in the Jablanica River Basin, Serbia

The aim of this research is to determine the change in the spatial distribution of erosion intensity in the territory of the Jablanica River Basin in the period 1971-2016 caused by land use and demographic changes. The Erosion Potential Method (EPM) was used to quantify changes in erosion intensity and to estimate the total annual sediment yield. The research results show that the value of the erosion coefficient decreased from 0.432 in 1971 to 0.360 in 2016. Specific annual gross erosion in the Jablanica River Basin was 654.41 m(3)/km(2)/year in 1971, while in 2016 it was 472.03 m(3)/km(2)/year. The analysis of proportional changes was used to determine demographic changes and land use patterns in the basin area. In terms of the scale and intensity of the erosion process, three types and one sub-type of population dynamics of settlements and land use changes were distinguished, respectively: progressive, stagnant, regressive and dominant regressive. It was concluded that the results show the significance of demographic and land use changes in the control of the intensity of erosion. The Soil Erosion Map may be useful to planners and land use managers to take appropriate decisions for soil conservation in the basin

Statistical analysis of water quality parameters in the basin of the Nisava River (Serbia) in the period 2009-2018

This paper analyzes water quality from four hydrological stations in the Nisava river basin from 2009-2018 based on the following parameters: pH, conductivity, O-2 saturation, BOD5, suspended solids, total oxidized nitrogen, phosphates, turbidity and coliform bacteria. Authors have applied WQI (water quality index) as the most reliable indicator of the watercourses pollution for setting of surface water flow quality. Statistical analysis of variance (ANOVA) using t-test inferential statistical analysis and post-hoc Tukey test were applied to evaluate statistically significant differences between specific data groups. The results show that bad water quality was registered on all the profiles on an annual basis (WQI = 65-71). The river water pH decreases downstream, while values of BOD5, suspended solids, turbidity, TON, phosphates and coliform bacteria gradually increase. The waters of the Nisava at the station Nis belong to the third class of waters and they are mostly loaded with organic matter originating from waste sewage and industrial waters of both urban and rural areas

Statistical analysis of temperature regime change on the example of Sokobanja basin in eastern Serbia

The changes and oscillations in air temperature during the second half of the 20th and in the early 21st century, have become one of the major concerns of almost all scientific disciplines. Such changes are noticeable both at the local and global level. The objective of this paper is to point out that the changes of this climate element can also be detected at the local level. The research underlying this paper is, in terms of territory, limited to the Sokobanja basin in Eastern Serbia. The analysis relies on the data on air temperature for the period 1946-2012 taken from the Meteorological weather station located in Sokobanja. The obtained data were processed in line with the recommendations of the World Meteorological Organization. The evidenced statistically significant changes in air temperature were examined using the following statistical tests: Pettit test, Standard Normal Homogeneity test, Buishand range test, and von Neumann test

Statistical analysis of annual and seasonal temperature regime change in Rasina River basin, Serbia

In this research, changes in annual and seasonal trends of mean temperatures were analyzed on the territory of the Rasina River basin (central Serbia). We used data from four meteorological stations during three periods: 1961–1989, 1990–2018, and 1979–2013. The change detection analysis has been conceded using the Pettitt’s test, von Neumann ratio test, Buishand’s range test, and standard normal homogeneity (SNH) test, while the linear regression, Mann-Kendall, and Sen's slope tests have been applied for trend analysis. The results show that the change in summer temperatures occurred shortly after 1980. The analysis results showed that inhomogeneous structures are generally observed between 1976 and 1984, between 1997 and 1998, and in 2006. The trend of all the data on annual basis showed positive increasing trend. The analysis indicated that the average annual, winter, and summer temperatures show significant increasing trend both in the longer period (1961–2018) and in the second part of the period (1990–2018). In the first part of the period (1961–1989), autumn temperatures in Kruševac, summer and autumn temperatures in Blace, as well as winter and autumn temperatures in Goč showed significant decreasing trend. The significant rising trend in the summer and winter months in the last 30 years may affect water availability and water demands in the region

The impact of Mediterranean oscillations on periodicity and trend of temperature in the valley of the Nisava river - a fourier and wavelet approach

Periodicity of temperature on three stations in the Nisava River valley in period 1949-2014, has been analyzed by means of Fourier and wavelet transforms. Combined periodogram based on fast Fourier transform shows considerable similarity among individual series and identffies significant periods on 2.2, 2.7, 3.3, 5, 6-7, and 8.2 years in all datasets. Wavelet coherence analysis connects strongest 6-7 years spectral component to Mediterranean oscillation, starting in 1980s. Combined periodogram of Mediterranean oscillation index reveals 6-7 years spectral component as a dominant mode in period 1949-2014. Wavelet power spectra and partial combined periodograms show absence of 6-7 years component before 1975, after which this component becomes dominant in the spectrum. Consistency between alternation in temperature trend in the Nisava River valley and change in periodicity of Mediterranean oscillation was found

A multi-site campaign to measure solar-like oscillations in Procyon. II. Mode frequencies

We have analyzed data from a multi-site campaign to observe oscillations in the F5 star Procyon. The data consist of high-precision velocities that we obtained over more than three weeks with eleven telescopes. A new method for adjusting the data weights allows us to suppress the sidelobes in the power spectrum. Stacking the power spectrum in a so-called echelle diagram reveals two clear ridges that we identify with even and odd values of the angular degree (l=0 and 2, and l=1 and 3, respectively). We interpret a strong, narrow peak at 446 muHz that lies close to the l=1 ridge as a mode with mixed character. We show that the frequencies of the ridge centroids and their separations are useful diagnostics for asteroseismology. In particular, variations in the large separation appear to indicate a glitch in the sound-speed profile at an acoustic depth of about 1000 s. We list frequencies for 55 modes extracted from the data spanning 20 radial orders, a range comparable to the best solar data, which will provide valuable constraints for theoretical models. A preliminary comparison with published models shows that the offset between observed and calculated frequencies for the radial modes is very different for Procyon than for the Sun and other cool stars. We find the mean lifetime of the modes in Procyon to be 1.29 +0.55/-0.49 days, which is significantly shorter than the 2-4 days seen in the Sun.Comment: accepted for publication in Ap

The effect of air temperature on forest fire risk in the municipality of Negotin

Fires in nature are caused by moisture content in the burning material, which is dependent on the values of the climatic elements. The occurrence of these fires in Serbia is becoming more common, depending on the intensity and duration have a major impact on the state of vegetation. The aim of this study was to determine the association between changes in air temperature and the dynamics of the appearance of forest fires. To study the association of these properties were used Pearson correlation coefficients. The analysis is based on meteorological data obtained from meteorological station in Negotin for the period 1991-2010. Research has found that the annual number of fires, correlating with an average annual air temperature (p = 0.317, ñ = 0.21). Also, it was found that the annual number of fires positive, medium intensity, correlate with the absolute maximum air temperature (p = 0.578, ñ = 0.26), but not statistically significant (p> 0.05)

Thermal characteristics of air of the basin of Nis for the purpose of quicker economic development

The characteristics of air temperature or heat mode the air is an important segment of the overall climate and the natural resource factor in the economic development of any place or region. In order to properly determine those, needs is a continuous series of data for at least 25-35 years. As longer as series are, the obtained data are more realistic. Weather Station-observatory "Tvrdjava" in Nis (φ-430 20 ', λ-21054', h-201 m), is the only higher-order station in the Niš valley, so, for determining the thermal properties of air, used measurement data from this station, for the period 1950-2009. Based on this 60-year period, analyzed the mean monthly, extreme temperature and annual temperature, the certain temperature thresholds and dates of onset for characteristic temperatures, and analyzed the frequency of occurrence some typical days