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Gdańsk is an important Polish city and harbour situated on the southern coast of the Baltic Sea in the Gulf of Gdańsk, in the lowland delta at the mouth of the Vistula River. At present Gdańsk has 460 thousand inhabitants and covers an area of 262 km2. The population and the area of the city have not changed over recent decades. In previous centuries the city was affected by severe floods, which caused considerable economic damage and the death of inhabitants. Most of these floods were caused by ice jams. The complicated system of rivers and channels within the city and in its close surroundings is called the Gdańsk Water Node (GWN ). The possible directions of flood hazard are: from the sea (Martwa Vistula), and from the main Vistula channel in the case of a breached left embankment. Flood hazard from the catchment of the RC h was not considered by city authorities. In July 2001, a devastating flash flood unexpectedly hit the city of Gdańsk. The paper presents this flood as a case study, without reference to other floods of similar character. It describes the city of Gdańsk, which is an important economic, cultural, scientific, political and industrial center, the system of rivers and channels within Gdańsk which form Gdańsk Water Node (GWN ), the precipitation regime, the course of the flood, and its effects. A special project was formulated after the flood with the aim of developing the proposal of new hydraulic engineering solutions in the GWN and in the catchment of Radunia Channel to prevent similar floods in the city in cases of rainfall similar to that of 2001. The paper also presents the implementation of the proposed engineering solutions.
The Vistula is the Poland’s largest River. It flows from the south to the north and has its mouth in the Baltic Sea. Hydrographically the Vistula is divided into three sections: the Upper Vistula from the source to San tributary; the Middle Vistula up to the Narew tributary; and the Lower Vistula till the outlet to the sea. The Lower Vistula is 391 km in length. Along it there are several very important urban centers: Gdańsk with its harbor and container terminal, Elbląg with its harbor situated on the Vistula Lagoon, Tczew, Grudziądz, Włocławek, Płock and Warsaw, the capital of Poland. The Lower Vistula establishes part of the International Waterway E70 and E40 as it has important economic value and development potential. The Lower Vistula has important hydroenergy potential, is the source of water supply for people, industry and agriculture as well as being a very important ecological corridor. The whole length of the Lower Vistula, except for Włocławek Reservoir is included in the NATURA 2000 Program. The Włocławek hydraulic project lies along this section. It was commissioned in 1970 and has been the source of significant debate discussion between ecologists and water resources specialists. The Lower Vistula also benefits from scenic countryside and is popular for tourism and recreation. Along the Lower Vistula, a very important problem still exists in the form of flood hazard, mainly caused by ice phenomena and is also endangered by droughts. The paper begins with a short discussion about sustainable development. It then presents the current state of the management of the Lower Vistula and its catchment, its economic potential and plans for development. Possibilities regarding the construction of future hydraulic projects are also discussed, including the benefits for energy production, navigation, water supply, tourism and recreation.
During the austral summer of 2002/2003 the author collected 38 marine and/or glacio-marine sediment samples from Admiralty Bay on King George Island (South Shetland Islands, West Antarctica). Recent "living" (Rose Bengal stained) and "dead" (subfossil) benthic foraminifera represented by 105 species belonging to 65 genera are recognized in samples from water depths of up to 520 m. They show large spatial variability. Four distinctive foraminiferal zones within the fjord of Admiralty Bay were recognized and analyzed in terms of environmental conditions. The zones are: restricted coves, open inlets, intermediate-, and deep-waters. The major environmental factors, which dictate foraminiferal distribution, are closely related to bathymetry and distance to open sea. Sediment composition and chlorophyll content appear to have minor influence on foraminiferal communities. Most diverse, deep-water faunas dominate water-depths below 200 m, which seems to be the lowest limit of atmospheric and meltwater influence. In waters shallower than 200 m, environmental features, affecting distribution of various benthic foraminiferal assemblages, appear to be sedimentation rate and hydrographic isolation. The results of this study gives promise to use the Admiralty Bay foraminiferal distribution pattern as a paleo- environmental tool for shallow- to intermediate-water Quaternary marine research in fjord settings of the South Shetland Islands.
The response of planktonic foraminifera to changing oceanographic conditions during Middle Miocene Climate Transition (MMCT) ~14 million years ago (Ma) at ODP Site 747 (Kergeulen Plateau) is investigated. Faunal changes are presented in the background of sea surface temperature (SST) estimates and multi−taxon δ18O and δ13C data presented in other studies. Four faunal transitions are distinguished between 15.0 and 12.2 Ma. The first two affected only a limited number of taxa, and do not lead to large−scale assemblage reorganizations. They are only minor assemblage changes within the pre−MMCT fauna. The first (14.5–14.4 Ma) is marked by a reduction in the Globorotalia zealandica plexus in favor of the Globorotalia praescitula plexus, coupled with the first signs of increased seasonality. The second (14.3–14.2 Ma) is characterized by recovery and diversification of the G. zealandica plexus and an increase in Turborotalita quinqueloba in response to further enhanced seasonality. The third faunal transition across the Middle Miocene Shift (MMS) in 18O (13.9–13.8 Ma) affects almost all planktonic foraminifera, leading to dismembering of the pre−MMCT assemblage. These changes were triggered by the SST drop by ~7C, followed by reduced sea−surface salinity following the MMS, which favored the opportunistic Neogloboquadrina continuosa. Its dominance spans the transitional period (13.8–13.2 Ma), during which several planktonic foraminiferal events gradually shaped the post−MMCT assemblage. The fourth faunal threshold took place during the hiatus in the ODP Hole 747A record spanning 13.2–12.5 Ma. It is expressed by the establishment of an assemblage dominated by Globorotalia praescitula and Globigerina bulloides in association with diminishing of the low−salinity surface layer. The two dominant taxa exhibit well−defined morphologies, much different from their earlier relatives. The microperforate foraminifera show relatively few morphological changes, probably due to their morphological conservatism. Their changes are thought to herald the large foraminiferal transformations, especially in case of the third and fourth faunal transition thresholds.
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Urban flash flood in Gdansk, 2001

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Floods in urban areas cause considerable economic losses and affect many people. Measures for flood mitigation in urban areas are primarily of an engineering character, however, existing city infrastructure very often restricts the introduction of appropriate new constructions. The city of Gdańsk is situated at the mouth of the Vistula river, on the area, which forms Vistula delta. It is the most flood-prone agglomeration in Poland. Now there are three possible flood sources. The first is from the moraine hills, in case of intensive precipitation. This area was recently rapidly urbanized. The second source of fl ood is from the Gulf of Gdańsk caused by storm surges and the third is from main channel of Vistula river in case of very high discharge or ice jam. The city of Gdańsk is situated within a complicated system of rivers and channels called Gdańsk Water Node (GWN). It is influenced by the discharge of rivers flowing from the moraine hills in the west, and from possible storm surges in the Gulf of Gdańsk. In July 2001 a severe flash flood, arising for the fi rst time from the moraine hills, caused by very intensive rainfall, hit Gdańsk. In the paper description of the operation of GWN, the flood cause, run and damages are presented. Description of measures, which were proposed to mitigate infl uence of a similar flood in the future are given. These measures were proposed on the basis of detailed field measurements, hydrologic analysis, hydraulic calculations and possible hydro-engineering developments.
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