Annual and seasonal variations of river discharges in the South Morava River Basin (Republic of Serbia)

Abstract

Understanding the current status of wateriness, which include studying the variability of different hydrological parameters over a long period of time, represents a significant process for determining the availability and quantity of water resources, especially at the local and regional level. First, it is necessary to identify certain paternity and frequency in a long time series of hydrological parameters. Secondly, it is important to correlate them with variability of some climatological elements on the one hand and anthropogenic influence in other hand, which are the main factors that have influence on the changes in river wateriness. The main objective of this paper is the analysis of seasonal and annual variations of river discharges in the South Morava river basin, for the period of 50 years (1968-2017), and the observation of certain trends (using non-parametric Mann-Kendall test and homogeneity test). Explanation and understanding the potential causes of observed changes, which are significant, is one of the tasks of this research. In this paper are observed data of the mean annual and monthly river discharges from 20 active hydrological stations in the South Morava river basin, for which there are empirical data for the taken period. The results indicate that most rivers in the basin have dominant decreasing trend of the mean annual river discharges (85% of them), but the more significant changes are noticed for the values of the seasonal river discharges.