Peer-reviewed articles 17,970 +



Title: DYNAMICS OF BEDFORMS IN THE DANUBE DELTA, SULINA CHANNEL

DYNAMICS OF BEDFORMS IN THE DANUBE DELTA, SULINA CHANNEL
D. Florin;L. Tiron Dutu;A. Popa
1314-2704
English
20
3.1
In the Danube delta, on the Sulina Channel, the morphology and bedforms characteristics have been investigated. 3D bathymetry, flow velocity, and bed sediments data have been acquired, in order to investigate the dynamic of the bedforms, the distribution of the water, and their influence against the river bed. A single observation (in May 2019) was made regarding the geometry, sediment composition and hydraulic conditions under which the dunes grew and decomposed. The investigation focuses here mostly on the geometrical parameters of these bed forms such as height, length, as well as grain size characteristics of the sediment and water dynamics. Based on in-site measurements different hydraulic parameters were calculated such as stream power and bed shear stresses. During the field campaign, the measured water mean velocity was from v = 0.10?1.18 m.s-1 for a water discharge (measured upstream, at the bifurcation, knot Ceatal St. George) of 1511 m3.s-1. At the same time the measured shear stresses within the dune field formation were from ?0 = 1.12 N.m-2 (on the ?Big M? meander) to 4.77 N.m-2 (on the main channel). Sediment samples were acquired throughout several cross-sections, in order to investigate the bed sediment characteristics and dynamics. Four types of bedforms have been distinguished, including flat bed, megaripples, and small and large dunes, and there is a good exponential correlation between H and L of all bedforms. However, the megaripples that were identified in the bed as singular primary forms, or overlapping the dunes (as secondary forms), were quite large in size near the maximum limit of evolution. We have found that the maximum height is situated at H = 0.0679L0.6737, with R2 = 0.6102. The relation H/L is situated for all the cases below 0.06 (between 0.003 and 0.06).
conference
20th International Multidisciplinary Scientific GeoConference SGEM 2020
20th International Multidisciplinary Scientific GeoConference SGEM 2020, 18 - 24 August, 2020
Proceedings Paper
STEF92 Technology
International Multidisciplinary Scientific GeoConference-SGEM
SWS Scholarly Society; Acad Sci Czech Republ; Latvian Acad Sci; Polish Acad Sci; Russian Acad Sci; Serbian Acad Sci & Arts; Natl Acad Sci Ukraine; Natl Acad Sci Armenia; Sci Council Japan; European Acad Sci, Arts & Letters; Acad Fine Arts Zagreb Croatia; C
83-90
18 - 24 August, 2020
website
cdrom
7107
bedform; hydro-morphology processes; Sulina Channel; multibeam measurements; human impact