Dynamics of Scour Hole the Entrance to Kaliningrad Bay
The paper presents the results of an analysis of the morphometric characteristics of scour hole located in the Strait of Baltiysk, which is the entrance to the Vistula Lagoon of the Baltic Sea. The temporal variation of main morphometric characteristics of the hole was analyzed for 9-year period (2008–2016) by year-to-year comparing the data of the digital relief model, changes of the contours of isobaths and displacement of the peaks in hole bathymetry. Specific attention was put the volume of deepest part of the hole – the volume below the isobaths of 21 m, 25 m, 27 m till maximum depths. It was found that, in general for the 9-year period (2008–2016), the volume of the hole increased, the average volume growth was 2450 m3/year. The growth was not monotonous, the deviation from the trend line was -9–6 %. The minimum volume was observed in the period of 2011–2013. The percentage changes in volume were up to 27 % in relation to the minimum volume found for the study period. Two peaks (‘northern’, the ‘near-mole’) and three erosive troughs (which volume gradually increased during studied period) were revealed in the morphometric structure of depression, These troughs elongated in different directions from the peaks, were marked, as the ‘northern’, the ‘near-mole’ and the ‘wraparound’ troughs. Synchronicity in the changes in the position of these two peaks was not observed, but on the whole both peaks were deepened approximately by 1 meter during the study period. Analysis of the dynamics of the depths along main longitudinal and transverse transects showed strong erosion of the base of the wall of the southern mole. The offshore slope of ‘northern’ troughs is conditionally stable, and the onshore slope has moved a little inside the strait for a distance of about 10 m. Analyzed information allows to put forward a hypothesis about the mechanisms of scour hole formation. It is assumed that it is supported by strong currents from the northern rumba due to the interaction of the alongshore current and the southern protective mole considerably protruding into the sea. The northern mole protruding into the sea reduces the cross-section of alongshore flow going from north to south. It is the reason of the acceleration of the flow near the end of the mole. This stream, interacting with the tip of the southern mole staying on its way, reflects from it, forms the central peak and the northern through, and also flow round the tip of the south mole from two sides, forming the outgoing arms of the ‘near-mole’ and the ‘wraparound’ troughs. The scour hole has not reached equilibrium and continues to increase in size. The shift of the onshore slope of the hole indicates a slow spreading of the hole deep into the Strait.
Zakirov Ruslan Bajaditovich, Postgraduate, Immanuel Kant Baltic Federal University, 14, A. Nevski st., Kaliningrad, 236041, Russian Federation, Senior Engineer, Shirshov Institute of Oceanology RAS, 36, Nakhimovski pr., Moscow, 117997, Russian Federation, tel.: (909)783-54-04, e-mail: email@example.com
Chubarenko Boris Valentinovich, Candidate of Sciences (Physical and Mathematical), Leading Researcher, Head Laboratory of Coastal Systems, Shirshov Institute of Oceanology RAS, 36, Nakhimovski pr., Moscow, 117997, Russian Federation, tel.: (906)239-10-32, e-mail: firstname.lastname@example.org
Sologub Sergej Petrovich, Head of Depth Control Group, FSUE “Rosmorport”, North-Western Basin Branch, 7, Pyetr Vyelikiy Quay, Kaliningrad, 236006, Russian Federation, tel.: (921)260-20-56, e-mail: email@example.com
Shusharin Aleksej Vital'evich, Chief Hydrograph, FSUE “Rosmorport”, North-Western Basin Branch, 7, Pyetr Vyelikiy Quay, Kaliningrad, 236006, Russian Federation, tel.: (4012)36-21-00, e-mail: firstname.lastname@example.org. ru
Zakirov R.B., Chubarenko B.V., Sologub S.P., Shusharin A.V. Dynamics of Scour Hole the Entrance to Kaliningrad Bay. The Bulletin of Irkutsk State University. Series Earth Sciences, 2018, vol. 26, pp. 46-59. https://doi.org/10.26516/2073-3402.2018.26.46 (in Russian)
Babakov A.N. Harakteristika pridonnyh techenij Gdan'skogo zaliva v blizi vhodnyh molov porta Baltijsk po dannym naturnyh izmerenij [Characteristics of the bottom currents of the Gdansk Bay in the region of the entrance port of Baltiysk according to field measurements]. Uchenye zapiski Russkogo geograficheskogo obshhestva (Kaliningradskaja oblast') [Scientific notes of the Russian Geographical Society (Kaliningrad Region)], 2008, vol. 7, part 1, pp. G1-G6. (in Russian)
Bass O.V. Jevoljucija vzaimodejstvija prirodnyh i tehnogennyh processov v hode stroitel'stva porta Baltijsk [Evolution of the interaction of natural and man-made processes during the construction of the port of Baltiysk]. Vestnik Kaliningradskogo gosudarstvennogo universiteta [Bulletin of the Kaliningrad State University], 2007, no. 7, pp. 35-43. (in Russian)
Bass O.V., Zhindarev L.A. Tehnogenez v beregovoj zone peschanyh poberezhij vnutrennih morej (st. 2. Vlijanie portovyh ograditel'nyh sooruzhenij na morfodinamiku beregovoj zony Jugo-Vostochnoj Baltiki) [Technogenesis in the coastal zone of sandy coasts of inland seas (art. 2. Influence of port fencing structures on the morphodynamics of the coastal zone of the South-Eastern Baltic)]. Geomorfologija [Geomorphology], 2011, no. 2, pp. 35-41. (in Russian)
Davydenko L.V. Kaliningradskij morskoj kanal [The Kaliningrad Sea Channel]. Kaliningrad, Zhivem Publ], 2011, 120 p. (in Russian)
Knaps R.D. Ograditel'nye sooruzhenija tipa molov I dvizhenie nanosov na peschanyh poberezh'jah [Fencing structures such as malls and sediment movement on sandy coasts]. Izvestija akademii nauk Latv. SSR [Izvestiya of the Academy of Sciences of Latvia. SSR], 1952, no. 6, pp. 87-130. (in Russian)
Lazarenko L.L. Gidrometeorologicheskij rezhim Vislinskogo zaliva [Hydrometeorological regime of the Vistula Lagoon]. Leningrad, Gidrometizdat Publ., 1971, pp. 130-142. (in Russian)
Chechko V.A. Processy sovremennogo osadkoobrazovanija v Vislinskom zalive Baltijskogo morja. Avtoref. dis. Na soisk. uchen. step. kand. geol.-miner. nauk [Processes of modern sedimentation in the Vistula Lagoon of the Baltic Sea. Cand. sci. diss. abstr.]. Moskow, 2007, 25 p. (in Russian)
Acharya A., Acharya A., Duan J.G. Three dimensional simulation of flow around series of spur dikes. International Refereed Journal of Engineering and Science, 2013 vol. 2, no. 7, pp. 36-57.
Beltaos S., Krishnappan B., Roswell R., Carter T., Pilling R., Bergeron E. Flow Structure and Channel Stability at the Site of a Deep Scour Hole, Mackenzie Delta, Canada. Journal of Arctic, 2012, vol. 65, no. 2, pp. 182-194.
Chubarenko B., Margonski P. The Vistula Lagoon. Ecology of Baltic Coastal Waters. Ecological Studies. Schiewer, 2008, pp. 167-195.
Connecticut Department of Transportation (ConnDOT). Erosion, Sedimentation, and Debris Control. “ConnDOT drainage manual” 2002. pp. 2. URL: http://www.ct.gov/dot/cwp/view.asp?a=3200&q=260108.
Hughes S.A. Equilibrium cross sectional area at tidal inlets. Journal Coastal Research, West Palm Beach (Florida). 2002. pp. 160-174. ISSN 0749-0208.
Kirkil G., Constantinescu G., Ettema R. The Horseshoe Vortex System around a Circular Bridge Pier on Equilibrium Scour Bed. World Water and Environmental Resources Congress, Alaska, USA, 2005, pp. 1-12.
Kjerfv B., Shao C.C., Stapor Jr. Formation of deep scour holes at the junction of tidal creeks: an hypothesis. Mar. Geol., 33, 1979, pp. M9-M14.
Steven A., Hughes J., Kamphuis W. Scour at coastal inlet structures / Proceedings of 25th Conference on Coastal Engineering, Orlando, Florida, 1996. pp. 1-14.
Yutao Guan y., Flood R. Morphologic analysis of Shinnecock Inlet using multibeam sonar // Long Island Geologists' Abstracts Collection [SBU], Marine Sciences Research Center State University of New York at Stony Brook, 2010, 3 p.