Establishment of the Sediment Monitoring System for the Sava River Basin - Page 5

Monitoring of Morphological Changes

Monitoring of siltation in reservoirs and morphological changes in rivers is usually performed by hydrographic survey of a channel bed (Figure 6). The surveys are usually made from a boat by using single-beam or multi-beam sonar. The location of a boat/sonar and vertical elevation is gained by RTK-GPS so the 3D absolute coordinates of a channel bottom can be produced. A comparison of repeated hydrographic surveys shows the changes of sedimentation in reservoirs or morphological changes of the river bed.


Figure 6: Single-beam and multi-beam hydrographic surveys.


Proposed Future Sediment Monitoring Network

Future sediment monitoring network should cover the whole SRB, i.e. all river basins larger than 1000 km2. However, monitoring of sediment on the Sava River main course is crucial and should be established as the first phase of the future SRB monitoring network development. Besides the monitoring along the Sava, sediment should be monitored at profiles established on the lowest sections of its main tributaries to get the clear picture on their role in the Sava River sediment balance. The map of future common monitoring network is presented on Figure 7, and their list is given in Table 3.


Figure 7: Map of SRB and sediment monitoring profiles.