The future of the reservoirs in the Siret River Basin considering the sediment transport of rivers (ROMANIA)

Petru OLARIU, Gianina Maria COJOC, Alina TIRNOVAN, Florin OBREJA

Abstract


The Siret River Basin is characterized by an important use of hydro potential, resulted in the number of reservoirs constructed and operational. The cascade power stage of the reservoirs on Bistrita and Siret rivers indicate the anthropic interventions with different purposes (hydro energy, water supply, irrigation etc.) in the Siret River Basin. In terms of the capacity in the Siret River Basin there is a dominance of the small capacity reservoirs, which is given by the less than 20 mil m³ volumes. Only two lakes have capacities over 200 mil m³: Izvoru Muntelui on Bistrita River and Siriu on Buzau River. Based on the monitoring of the alluvial flow at the hydrometric stations, from the Siret River Basin, there have been analysed the sediment yield formation and the solid transit dimensions in order to obtain typical values for the geographical areas of this territory. The silting of these reservoirs was monitored by successive topobatimetric measurements performed by the Bureau of Prognosis, Hydrology and Hydrogeology and a compartment within Hidroelectrica S.A. Piatra Neamt Subsidiary. The quantities of the deposited sediments are very impressive. The annual rates range betwee3 000 – 2 000 000 t/year, depending on the size of the hydrographical basin, the capacity of the reservoirs, the liquid flow and many other factors which may influence the upstream transport of sediments. These rates of sedimentation lead to a high degree of silting in the reservoirs. Many of them are silted over 50% of the initial capacity and the others even more. The effects of the silting have an important impact when analysing the effective exploitation of the reservoirs. 

Keywords


Reservoir, silting, alluvial deposits, Siret River Basin

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References


Ciaglic V., Vornicu P., Stefan A., Rudnic I. and Micu I. 1973. Contribuţii la cunoaşterea fenomenului de colmatare a lacului de acumulare Pângaraţi. Hidrobiologia 14.

Obreja F. 2012. Assessment of trap efficiency of the reservoirs in the Siret Basin (Romania). Scientific Annals of Stefan cel Mare University of Suceava. Geography Series 21, 107-117.

Olariu P. 1988. Tendinţe în evoluţia scurgerii aluviunilor în suspensie în bazinul hidrografic Siret, în raport cu modificările mediului geografic. Lucrările celui deal III-lea Simpozion „Provenienţa şi efluenţa aluviunilor”, Piatra Neamţ.

Olariu P. 1990. Controlul producţiei de aluviuni în bazinul hidrografic Bistriţa. Lucrările celui de al III-lea simpozion „Provenienţa şi efluenţa aluviunilor”, Piatra Neamţ.

Olariu P. 1992. Impactul antropic asupra regimului scurgerii apei şi aluviunilor în bazinul hidrografic Siret. Lucr. IV Simpozionului PEA, pp.121-130.

Olariu P. 1997. Gospodărirea tranzitului de aluviuni în spaţiul hidrografic Siret, in Măsuri nonstructuraleîn gospodărirea apelor, Editura H.G.A. Bucureşti.

Olariu P., Gheorghe D. 1999. The Effects of Human Activity on Land Erosion and suspended Sediment Transport in the Siret Hydrographic Basin, in Vegetation Land Use and Erosion Processes, Bucureşti.

Radoane M., Obreja F., Cristea I., Mihăilă D. 2013. Changes in the channel-bed level of the eastern Carpathian rivers: climatic vs. human control over the last 50 years. Geomorphology 193, 91–111

Radoane M., Radoane N. 2005. Dams, sediment sources and reservoir silting in Romania, Geomorphology 71, 217-226.