STUDY REGARDING THE RIVERBED MORPHOLOGICAL CHANGES OF THE DANUBE RIVER - EPURASU BRANCH

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7105-99-5 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 12, 841-848 pp, DOI: 10.5593/sgem2017/12/S02.107

ABSTRACT

This paper aims to analyse the link between the hydraulic structures and the watercourse riverbed. In this regard the Epurasu branch has been chosen as a case study area. This is a secondary branch of the Lower Danube, located between the 341-334 kilometers of the Danube River. Epurasu branch is in an advanced state of silting/colmation, possibly due to the unfinished damming works, from the mid-80s of the last century. Thus, over the years, various solutions have been proposed to ensure the longitudinal connectivity between the Danube and Epurasu branch. To improve navigation conditions on the Danube, from 2011 until 2016 a submerged guiding dam was built. Following the data obtained from the in situ monitoring activities conducted during this period, it has been observed the fact that the colmation process was emphasized, due to the low discharge which is distributed on Epurasu branch. As a solution to this issue, a groove was built into the submerged guiding dam body (proposed by INCDPM team). Over the years, under the influence of this anthropogenic intervention, the water discharge has shaped the riverbed, leading to significant morphological changes. Thus, based on the information volume obtained from the single-beam and multi-beam bathymetrical measurements, the situations regarding the riverbed differences in various stages of the construction have been compared. The riverbed morphological changes were investigated in the same sections, taking into account the situations before and after the submerged guiding dam construction and also the groove influence. The results obtained from the research highlighted the efficiency of hydraulic structures and provided preliminary data on the riverbed dynamics under the influence of anthropogenic interventions.

Keywords: Danube, hydro technical works, morphological changes, riverbed