River Sediment Transport in Serbia - page 06

Conclusions

The territory of Serbia and its natural geomorphology are conducive to erosion processes, given that three quarters of the territory is hilly or mountainous. Consequently, most domestic rivers feature significant sediment discharges. However, it should be noted that the largest watercourses in Serbia are transboundary rivers—the Danube, the Sava and the Tisa. Most of the sediment transport takes place along these rivers.

The assessment presented above shows the sediment regime of several characteristic watercourses, including large, medium and small rivers. In the large river category, sediment transport along the Velika Morava, the largest domestic river, is discussed. The conclusion is that sediment transport has recently been reduced. Erosion control and hydraulic engineering projects in the Velika Morava River Basin have decreased the production of eroded sediment and sediment is trapped within impoundments. The impoundments also retain a considerable amount of sediment delivered from the drainage areas of tributaries.

The Lim River was used as an example of a medium-sized river. The case study of that river is interesting because there is an impoundment where aggradation is monitored. A comparison of sediment measurement data and aggradation data revealed a relatively good match. Consequently, the conclusion is that Serbia's sediment database constitutes a sound basis for all river management activities.

The river sediment regimes of the Vlasina and the Toplica were assessed in the small river category. An especially interesting conclusion of that case study is that the hydrological and sediment regimes are in agreement. A more pronounced torrential nature of the Vlasina is reflected in higher rates of sediment discharge, especially in the high-flow range.

Serbia's river sediment monitoring network is not all-encompassing, such that not all the watercourses which are significant contributors to the sediment budget are covered. However, based on the existing sediment database, taking into account the erosion map and hydrological characteristics of significant watercourses, it is still possible to assess Serbia's approximated sediment budget. In that regard, the role of large river reservoirs in the sediment budget needs to be highlighted. There are several tens of such reservoirs in Serbia.