Technical Reports Parts C,D - ICPDR

Technical Reports – Part C: Water Quality 41
4.9. Suspended Solids Discharges
The rivers Prut and Siret drain the southeastern part of Ukrainian Carpaty. The average annual
discharge of suspended solids in the river Prut basin amounts up to 49-241 ton per km 2 per year,
30-39 ton per km 2 per year in Cheremosh River basin, 119 ton per km 2 per year in the Siret River
basin. The high rate of human induced denudation, calculated by suspended solid discharges,
occurs in the stream river basins with high human pressure (for example, Siret River basin).
The rivers Tisza, Latorytsia and Uzh have high-suspended solids discharges in many cases
exceeding 100 ton per km 2 per year. Only in upper reaches of Tisza, Tereblia and Borjava it varies
between 71-105 ton per m 2 per year. In the other river basins the suspended solids discharges vary
between 11-384 ton per km 2 per year.
The sediments of the majority of the rivers consist of the 5-10% particles with 0,5-1,0 mm in
diameter. The highest turbidity is reported for mountainous parts (up to 500-750 g per m 3 ). The
movement of bottom sediments is not sufficiently studied for the rivers of Western Ukraine. It is
reported that transport of bottom sediments consists of 10 -15 % of suspended solids. In
mountainous and semi-mountainous rivers this ratio may reach 70-90% and exceeds suspended
solids transport by 2-3 times.
4.10. Content of the Suspended Solids
Content of the suspended solids in the Danube water (Vilkovo) is presented in the Fig. 4.8.
Maximal content of suspended solids is observed during the summer seasons, and because the
rivers are not covered with ice during winter periods. Small peaks in springtime are related to the
spring flood events.
Figure 4.8.
60
Suspended sediment concentration in 1997 (mg/l), Danube,
Vilkovo
50
40
30
20
Left
Middle
Right
10
0
Jan Feb Mar Apr May Jun Jul
Aug Sep Oct Nov Dec