The Influence of Modern Alluvial Areas on Sea Level Changes in The Neva Bay During Storm Surges in The Conditions of Operation of The Saint Petersburg Flood Prevention Faculty Complex

Using numerical experiments with a three-dimensional baroclinic hydrodynamic model of the Baltic Sea, which covers the refined grid area around the Neva Delta and Neva Bay, and takes into account the operations of the Saint Petersburg Flood Prevention Facility Complex (FPFC), we investigate the influence of modern alluvial areas on sea level changes in the Neva Bay and Neva Delta during storm surges, under different volumes of Neva River discharge. The hydrological conditions that developed in early December 2015, when Storm Desmond approached St. Petersburg, which caused three dangerous level rises in the east of the Gulf of Finland, one after the other. The alluvial deposits of territories do not have noticeable changes in the sea level of the Neva Bay with the gates of the FPFC closed during storm surges. It is shown that, depending on the runoff of the Neva, with the gates of the FPFC closed, additional sea level rises in the Neva Bay due to alluviation do not exceed 1–5 cm, while in the Neva Delta they reach 20.5 cm. The rise of the sea level to 161 cm at the Mining University, at which floods are recorded in St. Petersburg, occurs due to alluviation 1–2 hours earlier. At the maximum volume of Neva runoff for the autumn-winter period, 27 hours after the closure of the gates of the FPFC, a dangerous flood is recorded in the Neva Bay near the Mining University point, and 48 hours later — a particularly dangerous one.

1. Pavlovsky A.A., Epifanova N.N., Shamshurin V.I. On urban planning features of the formation of artificial land plots in St. Petersburg. Environmental Protection of St. Petersburg. No.4(22) December 2021, 2021, 26–30 (in Russian).

2. Pomeranets K.S. On flood statistics in St. Petersburg. Meteorology and hydrology. 1999, 8, 105–110 (in Russian).

3. Averkiev A.S., Klevanny K.A. Determining cyclone trajectories and velocities leading to extreme sea level rises in the gulf of Finland. Russian Meteorology and Hydrology. 2007, 32, 514–519. doi:10.3103/S1068373907080067

4. Zakharchuk E.A., Tikhonova N.A. On the spatiotemporal structure and mechanisms of the Neva River flood formation. Russian Meteorology and Hydrology. 2011, 8, 534–541. doi:10.3103/S106837391108005X

5. Zakharchuk E.A., Sukhachev V.N., Tikhonova N.A. Mechanisms of dangerous sea level rises in the Gulf of Finland. St. Petersburg: Publishing house “Petersburg XXI century”, 2017, 151 p. (in Russian).

6. Zakharchuk E.A., Tikhonova N.A., Sukhachev V.N. Spatial Structure and Propagation of the Neva Flood Waves. Russian Meteorology and Hydrology. 2020, 45(4), 245–253. doi:10.3103/s1068373920040044

7. Zakharchuk E.A., Sukhachev V.N., Tikhonova N.A. Storm surges in the Gulf of Finland of the Baltic Sea. Vestnik of Saint Petersburg University. Earth Sciences. 2021, 66(4). doi:10.21638/spbu07.2021.408 (in Russian).

8. Labzovsky N.A. Non-periodic fluctuations in sea level. L.: Hydrometeoizdat, 1971. 238 p.

9. The Marine Encyclopedic Handbook: in two volumes. Volume 2. Edited by N.N. Isanin, L.: Shipbuilding, 1986, 520 p. (in Russian).

10. Horsburgh K., Haigh I.D., Williams J. et al. “Grey swan” storm surges pose a greater coastal flood hazard than climate change. Ocean Dynamics. 2021, 71, 715–730. doi:10.1007/s10236-021-01453-0

11. Guérou A., Meyssignac B., Prandi P. et al. Current observed global mean sea level rise and acceleration estimated from satellite altimetry and the associated measurement uncertainty. Ocean Science. 2023, 19, 431–451.

12. Zakharchuk E.A., Tikhonova N.A., Sukhachev V.N. Variability of the Baltic Sea level. Water resources in the context of global challenges: environmental problems, management, monitoring. Proceedings of the All-Russian Scientific and Practical Conference with international participation. September 20–22, 2023, Southern Federal University. Novocherkassk, Lik, 2023, 2, 57–62 (in Russian).

13. Passaro M., Müller F.L., Oelsmann J. et al. Absolute Baltic Sea Level Trends in the Satellite Altimetry Era: A Revisit. Frontiers in Marine Science. 2021, 8, 647607. doi:10.3389/fmars.2021.647607

14. Klevannyi K.A., Kolesov A.M., Mostamandi M.-S.V. Predicting the floods in St. Petersburg and the eastern part of the Gulf of Finland under conditions of operation of the flood prevention facility complex. Russian Meteorology and Hydrology. 2015, 40(2), 115–122. doi:10.3103/s1068373915020077

15. Klevanny K.A., Averkiev A.S. The influence of the work of the complex of protective structures of St. Petersburg from floods on the rise of the water level in the eastern part of the Gulf of Finland. Scientific and theoretical journal “Society — Environment –Development”. 2011, 1, 204–209 (in Russian).

16. Pavlovsky A.A., Menzhulin G.V. Climate change and assessment of the prospects for the use of artificial alluvial territories in St. Petersburg urban planning. Proceedings of the Voeikov Main Geophysical Observatory. 2019, 593, 70–84 (in Russian).

17. Popov S.K., Gusev A.V., Fomin V.V. The Secondary Sea Level Maximum during Floods in Saint Petersburg and Its Simulation with Numerical Models. Russian Meteorology and Hydrology. 2018, 43(12), 827–836. doi:10.3103/s1068373918120038

18. Zalesny V.B., Gusev A.V., Ivchenko V.O., Tamsalu R., Aps R. Numerical model of the Baltic Sea circulation. Russian Journal of Numerical Analysis and Mathematical Modelling. 2013, 28, 1, 85–100. doi:10.1515/rnam‑2013-0006

19. Zalesny V.B., Gusev A.V., Chernobay S. Yu. et al. The Baltic Sea circulation modelling and assessment of marine pollution. Russian Journal of Numerical Analysis and Mathematical Modelling. 2014, 29, 2, 129–138. doi:10.1515/rnam‑2014-0010

20. Brydon D., Sun S., Bleck R. A new approximation of the equation of state for seawater, suitable for numerical ocean models. Journal of Geophysical Research-Oceans. 1999, 104, 1537–1540. doi:10.1029/1998jc900059

21. Yakovlev N.G. Reproduction of the large-scale state of water and sea ice in the Arctic Ocean in 1948–2002: Part I. Numerical model. Izvestiya, Atmospheric and Oceanic Physics. 2009, 45(3), 357–371. doi:10.1134/s0001433809030098

22. Smolarkiewicz P. A fully multidimensional positive definite advection transport algorithm with small implicit diffusion. Journal of Computational Physics. 1984, 54, 325–362. doi:10.1016/0021-9991(84)90121-9

23. Hunke E.C., Dukowicz J.K. An elastic-viscous-plastic model for sea ice dynamics. Journal of Physical Oceanography. 1997, 27, 1849–1867. doi:10.1175/1520–0485(1997)027<1849: AEVPMF>2.0.CO;2

24. Hersbach H., Bell B., Berrisford P., et al. The ERA5 global reanalysis. Quarterly Journal of the Royal Meteorological Society. 2020, 146, 1999–2049. doi:10.1002/qj.3803

25. Belyshev A.P., Klevantsov Yu.P., Rozhkov V.A. Probabilistic analysis of sea currents. L., Hydrometeoizdat, 1983, 264 p. (in Russian).

26. Methodical letter on the probabilistic analysis of vector time series of current and wind velocity. L.: Hydrometeoizdat, 1984, 62 p. (in Russian).

27. Malakar P., Kesarkar A., Bhate J., Singh V., Deshamukhya A. Comparison of Reanalysis Data Sets to Comprehend the Evolution of Tropical Cyclones Over North Indian Ocean. Earth and Space Science. 2020, 7, e2019EA000978. doi:10.1029/2019EA000978

28. Li X., Yang J., Han G. et al. Tropical Cyclone Wind Field Reconstruction and Validation Using Measurements from SFMR and SMAP Radiometer. Remote Sensing. 2022, 14(16), 3929. doi:10.3390/rs14163929

29. Wübber C., Krauss W. The two-dimensional seiches of the Baltic Sea. Oceanologica Acta. 1979, 4(2), 435–446.

30. Zakharchuk E.A., Tikhonova N.А., Zakharova E., Kouraev A.V. Spatiotemporal structure of Baltic free sea level oscillations in barotropic and baroclinic conditions from hydrodynamic modelling. Ocean Science. 2021, 17(2), 543–559. doi:10.5194/os‑17-543-2021

31. Sukhachev V.N., Zakharchuk E.A., Klevantsov Yu.P., Tikhonova N.A. Variability of hydrological characteristics in the eastern part of the Gulf of Finland according to measurements at the automatic bottom station SPO GOIN. Problems of the Arctic and Antarctic. 2014, 3(101), 97–108 (in Russian).