Characterization of sedimentary depositional environments for land use and urban planning in Espoo, Finland

The capital region of Finland is growing rapidly and into areas with challenging con­struction conditions such as deep fine-grained sediments. In the coastal city of Espoo, present land use is mainly focused in the southern and central parts, which were submerged by the Baltic Sea during the early and mid-Holocene. These areas have experienced saline and brackish water phases during the history of the Baltic Sea Basin. The deposition environments of the presently studied onshore areas are an analogue for the present day offshore Baltic Sea sedimentation settings for fine-grained material. The results from Baltic Sea studies have demonstrated that the seabed topography has a significant role in the deposition of sediments and their properties. In this study, paleotopographic models were created for the ancient Baltic Sea Basin in the Espoo area 1) after deglaciation and 2) during the Litorina transgression and classified into bathymetric (terrain) zones and structures. Topographic classification was combined with the water depth of the Litorina stage, the thickness of fine-grained deposits and wind fetch to establish the overall characteristics of sedimentary environments in the coastal area. Fine-grained sediments can be found mainly in depressions that are classified here as broad, narrow or local. The study found the most challenging environments for construction purposes in sheltered narrow depressions that contain thick layers of fine-grained sediments deposited during the Litorina transgression. These are mainly located in the southern and central parts of Espoo. Minor deep canyons were also found in the northern parts of Espoo. This study provides new prior knowledge for urban planning and construction design in Espoo. The methodology could be applied to other Baltic Sea coastal cities and areas with fine-grained sediments.

The second stage of development of artificial reproduction technology of northern pike in the Kaliningrad lagoon basin

The second stage of development of northern pike artificial reproduction technology for stocking with larvae and fry in the Kaliningrad lagoon basin is considered in this paper. Today northern pike natural stocks in the Kaliningrad lagoon basin are not numerous due to unregulated fishery and limited spawning habitat. Since the 1990s, in many countries of the world, the number of natural stocking northern pike has gradually decreased and at present does not exceed several thousand tons. This problem is also relevant for the Baltic Sea basin, where the modern catches of northern pike in the Curonian and Kaliningrad lagoons make 7,2 and 0,6 tons respectively. At the present time different scientific programs and actions are realized in many countries to restore natural stocks of northern pike. One of the most promising solutions of low northern pike numbers problem is organization of northern pike artificial reproduction in the territory of the Kaliningrad Region. Based on our earlier research in the Curonian lagoon basin, the second stage of development of the technology of northern pike artificial reproduction was carried out on the basis of the educational and experimental farm of KSTU in 2020. Prespawning maintenance of 25 northern pike producers with the use of cages from deli, ponds and reclamation canal was carried out, as well as egg incubation and holding of prelarvae in RAS. As a result of the conducted researches, it was established, that the reproductive products of northern pike producers have high quality and the prelarvae at the stage of incubation have high survival rate (82,2–91,7%). The calculated of biometric parameters of producers and their reproductive products, confirmed the correlation between the weight of females and their fecundity, which was 0,86 and 0,95. The scheme of keeping of producers and incubation of northern pike eggs tested at the second stage has shown the prospect of providing 50% of the need in stocking of young northern pike in the Kaliningrad lagoon with the use of 100% stock of producers.

Basin-Scale 3D Sedimentary Modelling: An Approach to Subdivide Baltic Sea Onshore Sediments for Land use and Construction

Understanding the local stratigraphy and geometry of sediment units is necessary for successful 3D modelling and the prediction of ground behaviour and engineering-geological properties for urban land use and construction. A detailed 3D model of the main sediment units for the Rastaala basin in southern coastal Finland was constructed, combining a conceptual geological model and information from local drill-hole logs and geotechnical drilling. The 3D modelling was based on a cross-section approach, where sediment units were defined on the basis of lithological boundaries that are of major geotechnical importance for land use and construction. The conceptual geological model was based on a sequence of events that characterize the late- and postglacial evolution of the Rastaala basin. The present study combines the allostratigraphy and lithostratigraphy of unconsolidated glacial, late-and postglacial sediment units in southern coastal Finland. It also investigates the appearance and distribution of sediment units in the Rastaala basin and compares modelling and visualization results for unit surfaces and solids using two independent modelling software packages. Finally, information on the geotechnical properties of different sediment units in the Rastaala basin is provided so that they can be applied to other onshore regions with similar geological settings in the coastal Baltic Sea Basin.

Tracing the late Holocene storminess at the Polish Baltic Sea coast – regional survey and local in depth research.

<p>Within the Baltic Sea basin, the frequency and intensity of coastal flooding caused by storms is influenced by wind direction and exposure of the coast. Strong (north)westerly winds associated with the North Atlantic Oscillation hit large parts of the Polish coast, while (north)easterly winds affect Puck Bay. Following from that, the research on the frequency and magnitude of past storminess within the Baltic Sea sheds light onto regional climatic conditions indicating changes in wind-field directions and storminess in north-western and northern Europe. Despite the fact that the Baltic Sea basin area bears potentially vast amount of information on the past storminess and climatic conditions on the regional scale, no systematic, basin-wide research on storm deposits and analysis of frequency and intensity of storminess is available.</p><p> </p><p>The spatially variable occurrence of sedimentary evidence for coastal flooding caused by storms indicates necessity for multisite investigations in order to develop reliable records of past storm frequency and intensity. As the historical written sources and instrumental records are insufficient to draw informative conclusion on the past storminess, the survey in search for the depositional evidence of catastrophic coastal flooding has been undertaken along the Polish coast, from the Puck Bay to Wolin Island. Following from that, detailed research on the storm deposits has been undertaken in 4 key locations (one is presented here, Mechelinki).</p><p>The survey allowed to create the list of features common for the locations where sedimentary evidence for coastal flooding is preserved. These include flat, inundational character of the coast, prevailing organic deposition in lowlands close to the shore and non-tidal character of adjacent marine basin.</p><p>Mechelinki peatland (Puck Bay) is separated by a N-S extending sand barrier from the open sea and exposed to (north)easterly winds. Investigated sedimentary succession comprises ca. 450 cm of peat interdigitated with few centimetres thick layers of sand. The origin of sand has been established based on multiproxy investigation including: particle size, shape (automated MorphologyG3, thin sections), diatom, XRF and heavy mineral analyses. Geochronology has been established based on <sup>14</sup>C and <sup>210</sup>Pb/<sup>137</sup>Cs measurements. In the Mechelinki research site, the evidence for about 20 coastal flooding events which took place during the last 5000 years has been discovered. The results prove, there is no universal method to differentiate the storm deposits from the sediments of other origin and only the combination of multiproxy analyses bears unambiguous results.</p><p>The research project CatFlood is funded by National Science Centre, Poland, OPUS grant nr: 2018/29/B/ST10/00042</p>

Ensuring environmental safety of the Baltic Sea basin

The Baltic Sea is not only important for transport, but for a long time it has been supplying people with seafood. In 1998, the Government of the Russian Federation adopted Decree N 1202 “On approval of the 1992 Convention on the Protection of the Marine Environment of the Baltic Sea Region”, according to which Russia approved the Helsinki Convention and its obligations. However, the threat of eutrophication has become urgent for the Baltic Sea basin and Northwest region due to the increased concentration of phosphorus and nitrogen in wastewater. This article studies the methods of dephosphation of wastewater using industrial waste.

KHILCHEVSKYI V.K. MODERN CHARACTERISTICS OF WATER BODIES IN UKRAINE: WATERCOURSES AND RESERVOIRS

According to the assessment made in the article, the current data on the number of water bodies on the territory of Ukraine are: 63119 rivers; about 20 thousand lakes; 1054 reservoirs; 50793 ponds. There are rivers in Ukraine: large (> 50 thousand km2) – 8 rivers: Dnieper, Dniester, Danube, Desna, Pripyat, Southern Bug, Seversky Donets, Tisa; medium (2.0-50 thousand km2) – 82 rivers; small (<2.0 thousand km2) – 63,029 rivers (99.87%). There are lakes in Ukraine: very large (> 100 km2) – 1 lake: Yalpug; large (10-100 km2) – 21 lakes; medium (1-10 km2) – about 70; small (0.5-1.0 km2) and very small (<0.5 km2) - all other lakes (99.54%). There are reservoirs in Ukraine: very large (10-50 km3) – 2 reservoirs: Kremenchug and Kakhovskoe – on the river.Dnipro (0.2%); large (1.0-10 km3) – 5 reservoirs; Kievskoe,Kanevskoe, Kamenskoe, Dneprovskoe (on the Dnieper river), Dnestrovsky – on the Dniester (0.5%); medium (0.1-1.0 km3) – 11 reservoirs (1.0%); small (0.01-0.1 km3) – 88 reservoirs (8.4%); small (<0.01 km3) – 948 reservoirs (89.9%). There are ponds in Ukraine: very large (> 500 thousand m3) and large (200-500 thousand m3) – 13%; medium (50-200 thousand m3) – 29%; small (10-50 thousand m3) and very small (<10 thousand m3) - 58%. Of great importance was the approval by the Verkhovna Rada of Ukraine in 2016 of the hydrographic zoning of the territory of Ukraine with the allocation of 9 regions of river basins: the Dnieper, Dniester, Danube, Southern Bug, Don, Vistula, Crimean rivers Black Sea rivers, Azov rivers. Almost all rivers of Ukraine belong to the basin of the Black and Azov seas. In addition to the area of the river basin Vistula (Western Bug and San rivers) which belongs to the Baltic Sea basin and occupies only 2.5% of the country's territory. It is shown that since hydrographic studies in Ukraine were carried out more than 50 years ago, modern hydrographic surveys of the country’s territory with the creation of a modern water cadastre and the establishment of real morphometric parameters of water bodies (rivers, lakes, reservoirs, ponds) are necessary. The main organizations dealing with these issues are the State Agency for Water Resources of Ukraine and the Ukrainian Hydrometeorological Center of the State Service of Ukraine for Emergency Situations. It is also necessary to regulate a number of concepts that are used a priori, but do not have a definition, clear parameters (for example, a stream, a source, a digging pond, etc.). This is difficult to implement through the Water Code of Ukraine or state standards, but it can be easier to do through the officially approved methods in which these terms are used.

European river lamprey Lampetra fluviatilis L. in the Baltic and Caspian seas basins of Tver region

Представлена дополненная информация о распространении и условиях обитания речной миноги (Lampetra fluviatilis L.) на территории Тверской области. Ареал на территории области представляет собой сочетание исторического (водотоки бассейна Балтийского моря) и инвазионного (водотоки бассейна Каспийского моря) компонентов. Обоснована идея вселения миноги в систему р. Волга по системам искусственных судоходных каналов. Состояние популяций в Каспийском бассейне указывает на продолжающийся процесс освоения новых местообитаний. Additional information on the distribution and habitat of the European river lamprey (Lampetra fluviatilis L.) in the Tver Region is presented. The areal of the European river lamprey in the Region consists of the historical (watercourses of the Baltic Sea Basin) and invasive (watercourses of the Caspian Sea Basin) components. The idea of the lamprey invasion in the Volga River through the system of manmade shipping canals is substantiated. The condition of the lamprey’s populations in the Caspian Sea Basin indicates the ongoing process of the species expansion.