Spatial-temporarily variability and discharge trends in the Morača river basin

Abstract

The discharge is the most important element of the water balance and is very important for the study of the variability of a particular watercourse because it represents the reaction of the entire river basin to changes caused by natural or anthropogenic factors. This paper aims to present statistical analyzes of discharge variability in the Morača river basin, up to the profile of the Zlatica hydrological station (42°29'01.64"N and 19°18'25.04"E), which covers the surface of 772.4 km2. The multi-year mean discharge values range from 27.4 m3/s at HS Pernica to 58.9 m3/s at HS Zlatica. Maximum discharges occur during November (Pernica Q=46.7 m3/s) and December (Zlatica Q=112.2 m3/s) and coincide with maximum precipitation in the basin, while secondary maximum occur during April (Zlatica Q =97.8 m3/s and Pernica Q=45.2 m3/s), as a consequence of the air temperature increasing and the snow cover melting on the high mountain areas. Minimum water occurs in August (5.5-7.1 m3/s). The statistical significance of the discharge trend was examined using the non-parametric Mann-Kendall test, and the trend's slope was determined using Sen's slope.. The analysis of the results shows a statistically significant negative change in discharge at HS Zlatica in the autumn season, as well as during October (at a significance level of 95%), while at HS Pernica monthly changes (February, March, September and October) were recorded at a level of low statistical significance (90%). Knowing the basic elements of river regimes variablity is a necessary prerequisite for the optimal and rational use of water resources, such as the Morača River. Therefore, the obtained results represent a good basis for all future water management planning and research.