Sediment transport on the Romanian section of the Danube River

Abstract

The paper briefly presents the physico-geographical characteristics of the Danube River basin in order to introduce data and considerations on the river water and sediment discharges, focusing on the coarse-grained bed- and suspended loads.
The analysis of interactions between the water flow and the riverbed physical structure allowed to establish the empirical functions of the bed- and suspended coarse-grained sediment load transport. For a given cross-section a linear dependence between the average specific water discharge and the coarse sediment bed-load average specific discharge as well as the mean concentration of the suspended coarse sediment was found.

The coarse-grained sediment transport empirical functions based on a long series data for the period 1965 – 1989 allowed the determination of the daily coarse-grained bed- and suspended sediment discharges along the Romanian Danube River section for an extended period between 1840 and 2012.

The multiannual average values and maximum annual discharges of the bed- and suspended coarse-grained sediment load (d50%>0.063 mm) have been
computed for the cross-sections downstream the Iron Gates barrages.

For the coarse-grained bed load:

• The multiannual average values of the bed-load discharge vary from 14.6 kg/s at Gruia (km 856.5) to 5.6 kg/s at Ceatal Ismail (Km 80.5);


• The maximum values of the bed-load discharge vary between 23.9 kg/s at Zimnicea (km 553.23) and 47.9 kg/s at Grindu (km 141.3).


• For the coarse-grained suspended load:


• The multiannual average values of the coarse-grained suspended load discharge vary between 54.1 kg/s at Zimnicea and 130.1 kg/s at Ceatal Ismail;


• The maximum values of the coarse-grained suspended load discharge vary from 400 kg/s at Corabia (km 624.2) to 2048 kg/s at Ceatal Ismail.