On a mathematical model of simulating the hydraulic process of bars’ formation at the Danube River mouths

• Main Author: BONDAR Constantin
• Format: Article
• Language: English
• Published: CITDD Publishing House 2018-05-01
• Series: Scientific Annals of the Danube Delta Institute
• Subjects: hydraulic process; hydraulic simulation; Danube’s mouth; bar formation
• Online Access: http://www.ddniscientificannals.ro/scientific-annals/24-volume-23/144-vol21_art03-20

The paper presents the description of the hydraulic process which takes place at the contact of the fluvial waters with the marine ones. The mathematical analysis of this hydraulic process is done and it results in two differential equations of the water flow. Both of them are related to the fluvial jets with variable discharge and constant discharge, respectively. The integration of the two differential equations was performed with finite differences at intervals of dx = 100 m, along the river jets, and two computing programs have been constructed in the Quick Basic 45 programming environment. Based on these programs, a mathematical model was constructed to simulate the fluvial sediment bars formation at the Sulina arm mouth where it meets the Black Sea waters. The results of simulation were compared to water depth measurements carried out within 1991-2009 on the central alignment of the bar. The model was tested using hydrological data from the 1978-2012 study interval, multiannual average monthly values of water discharges and coarse sediment transport, discharged by the Sulina arm mouth into the Black Sea. The model shows that the thickness of the bar alluvial layers deposited varies along the jets, extendinging off the sea up to a distance of about 1200 m. Based on the scenarios constructed in this model, the bar’s dredging technology and the zones to be dredged can be established as the water has e depth to assure a good maritime navigation on the Sulina mouth bar