Assessment of the potential for dredged material dispersal from dumping sites in the Gulf of Gdańsk

Abstract

Purpose Environment-friendly management of sites used for disposal of locally generated sedimentary material involves designation of an optimal dumping site location which will render the dredged material re-usable for beneficial purposes. The objective of this research was to determine whether wind, waves, and currents can induce transport of sediment from offshore dumping sites located at intermediate depths in the southern Baltic. Materials and methods The problem was addressed by exploring potential sediment transport from two sites located in the Gulf of Gdańsk at depths of about 20 m. A total of 29 combinations of hydrodynamic variables, representing the most extreme possible situations in the area, including eight theoretical uniform wind fields over the entire Baltic Sea from the W, NW, N, NE, E, SE, S, and SW sectors, the wind speed of 30 m s −1 , as well as 21 historical extreme storms, retrieved from the HIPOCAS project database, were used. Results and discussion The bottom velocities resulting from waves and currents at the dumping sites considered were computed using wave models (WAM, SWAN) and the M3D hydrodynamic model (based on the POM model). To estimate the velocities critical for bedload transport, formulae developed by Soulsby (1997) and Sawamoto and Yamashita (Proc Coastal Sediments 87:415-423, 1987) were used. The volumetric bedload transport was computed based on Meyer-Peter and Müller (1948). The model simulations demonstrated that, for the storm conditions analyzed, the current velocity in the area of the two dumping sites would be so low that it would practically not affect the magnitude of the bottom sediment transport. Thus, the resultant volume of bedload transported would be equal to that generated by the wave action. For the heaviest historical storm, the maximum transport is about 3 × 10 −5 m 2 s −1. Conclusions Under conditions of theoretical storms, the bottom orbital velocities would be higher and the resultant sediment transport would reach almost 7 × 10 −5 m 2 s −1 for northerly winds. However, this value is still very low compared with the volume of sediment being dumped. The findings of this study may prove useful in designation of future dumping sites.

Predicting Dominance of Sand Transport by Waves, Tides, and Their Interactions on Sandy Continental Shelves

“…Careful consideration must be taken to examine the validity of the assumptions made in the model used for training, and how well these represent net sand transport drivers in the area under consideration. This includes consideration of natural processes including wind‐driven/baroclinic circulations (Héquette et al., 2008), anthropogenic processes such as trawling and dredging (Cieślikiewicz et al., 2018; Mengual et al., 2019; Uncles et al., 2020), and potential future changes in forcing conditions due to climate change (Meucci et al., 2020; Young & Ribal, 2019). The computational efficiency of this method relative to running a coupled wave‐tide numerical model enables quick assessment to be made of the influence of changing environmental conditions such as upward trends in storminess across central, western, and northern Europe (Castelle et al., 2018; Donal et al., 2011) on the magnitude and dominant forces driving the net transport of sand on sandy continental shelves, with potential applications globally.…”

“…Residual (net) sediment transport patterns influence the transport and fate of continental shelf sediments, influencing sediment distributions and morphological evolution (Harris & Collins, 1991; King et al., 2019; Leonardi & Plater, 2017; Pingree & Griffiths, 1979; Pingree & Le Cann, 1989; Stride, 1963; van der Molen, 2002; Xu et al., 2016; Zhang et al., 2016). Waves and tidal currents result in resuspension and transport of shelf sediments (Carter & Heath, 1975; Pattiaratchi & Collins, 1988; Thompson et al., 2019), influencing sand wave morphology (Damen et al., 2018a, 2018b; Wang et al., 2019) with implications for marine spatial planning of pipelines and cables for windfarms and offshore renewable energy (Cheng et al., 2020; Németh et al., 2003; Roetert et al., 2017), mobilization and dispersal of sediments and contaminants (e.g., due to dredge disposal and bottom trawling; Cieślikiewicz et al., 2018; Mengual et al., 2019; Uncles et al., 2020), and the fate of shoreface nourishments (Luijendijk et al., 2017). Shear stresses and sand transport driven by tides and waves influence benthic communities through disturbance, while also acting as a vector for recolonization (Aldridge et al., 2015; Bricheno et al., 2015; Dernie et al., 2003; Hall, 1994; Harris, 2014; Levin, 1995; Reiss et al., 2010).…”

“…sand wave morphology (Damen et al, 2018a(Damen et al, , 2018bWang et al, 2019) with implications for marine spatial planning of pipelines and cables for windfarms and offshore renewable energy (Cheng et al, 2020;Németh et al, 2003;Roetert et al, 2017), mobilization and dispersal of sediments and contaminants (e.g., due to dredge disposal and bottom trawling; Cieślikiewicz et al, 2018;Mengual et al, 2019;Uncles et al, 2020), and the fate of shoreface nourishments (Luijendijk et al, 2017). Shear stresses and sand transport driven by tides and waves influence benthic communities through disturbance, while also acting as a vector for recolonization (Aldridge et al, 2015;Bricheno et al, 2015;Dernie et al, 2003;Hall, 1994;Harris, 2014;Levin, 1995;Reiss et al, 2010).…”

Predicting dominance of sand transport by waves, tides and their interactions on sandy continental shelves

“…This approach efficiently indicates where simple noninteractive wave and tide processes may be sufficient for modeling sediment transport, and enables efficient interregional comparisons and sensitivity testing to changing climate conditions with applications globally. sand wave morphology (Damen et al, 2018a(Damen et al, , 2018bWang et al, 2019) with implications for marine spatial planning of pipelines and cables for windfarms and offshore renewable energy (Cheng et al, 2020;Németh et al, 2003;Roetert et al, 2017), mobilization and dispersal of sediments and contaminants (e.g., due to dredge disposal and bottom trawling; Cieślikiewicz et al, 2018;Mengual et al, 2019;Uncles et al, 2020), and the fate of shoreface nourishments (Luijendijk et al, 2017). Shear stresses and sand transport driven by tides and waves influence benthic communities through disturbance, while also acting as a vector for recolonization (Aldridge et al, 2015;Bricheno et al, 2015;Dernie et al, 2003;Hall, 1994;Harris, 2014;Levin, 1995;Reiss et al, 2010).…”

Preface: Proceedings of the 14th IASWS international conference

“…The findings of this paper can be extended to the whole Baltic Sea that should be considered as more susceptible to ongoing climate changes than the open seas and mercury transformations connected with that process. The paper by Cieślikiewicz et al (2018) discussed the problems related to the assessment of the potential for dredged material dispersal from dumping sites in the Gulf of Gdańsk (Poland). The main purpose of this contribution was to determine whether wind, waves, and currents can induce transport of sediment from offshore dumping sites located at intermediate depths in the southern Baltic.…”