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Grawitacyjne ruchy masowe na obszarze Gdyni udokumentowane na dawnych mapach i w źródłach archiwalnych

Małka Anna

Przegląd Geologiczny

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2019

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Vol. 67, nr 5

308--317

EN

The article deals with selected examples of old nautical maps (portolans), topographic maps, archival materials of the 19th century German language studies, which are valuable sources of information on the history of landslide processes. The city of Gdynia was founded in 1926, and its location despite very unfavourable formation of mass movements, was determined by economic and political reasons. As documented on nautical maps from 1596, landslides have been occurring in the coastal zone of today’s Gdynia since at least the 16th century. Within the limits of the zone, the oldest structural damage has been observed. The Urmesstischblätter map from 1837 documented damage to the redoubt in Cypel Oksywski. These fortifications, which were erected during Napoleonic Wars between 1810 and 1812, were completely rouined in the first half of the 19th century. It was the first time when mass movement resulted in financial losses in Poland’s coastal zones. Compared with the present, the 19th century saw an increase in mass movement activation in coastal zones. Between 1837 and 1909 the maximal changes in Cypel Oksywski were 2.2 m a year. The landslide in Cypel Oksywski is also the first stabilized landslide within the city limits of Gdynia. It also has the longest history of stabilizing efforts that go back to 1909. This article shows, based on the study of a landslide in Wielki Kackfrom 1930, that in the development of the city of Gdynia virtually from the beginning of its foundation in 1926, man-made dangerous gravitational processes have always been present.

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Field trip in the Kerala : report

Rączkowska Z., Prokop P., Kijowska-Strugała M.

Landform Analysis

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2017

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Vol. 35

9--12

EN

This report contains short information about the geomorphological field trip in Kerala State. The field trip was largely focused on various geomorphological and geoecological aspects of laterites and backwaters which dominate in landscape of Kerala. One of the main highlights of the field trip was to the examination of type locality of laterite. Nearly 60% of the Kerala is covered by laterite or laterite-derived materials, and lateritisation process dominates the landform development from the coast to foothills. The second main highlights of the field trip was to the examination of backwaters which are a network of five big lakes (lagoons and estuaries) and rivers linked by natural and man-made canals.

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Naturalne i antropogeniczne przyczyny powstawania i reaktywacji ruchów masowych na obszarze miejskim Gdyni oraz związane z nimi zagrożenia

Małka A., Frydel J., Jurys L.

Biuletyn Państwowego Instytutu Geologicznego

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2017

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nr 470

63--80

PL

W artykule przedstawiono na wybranych przykładach analizę naturalnych i antropogenicznych uwarunkowań rozwoju ruchów masowych na obszarze miejskim Gdyni. Przedmiotem badań były rozległe zespoły osuwisk klifowych w Babich Dołach oraz na Cyplu Oksywskim i Cyplu Redłowskim o powierzchniach przekraczających 4 ha. Obszarowo są to formy dominujące, ponieważ zajmują ponad 60% powierzchni wszystkich gdyńskich osuwisk. Analizą objęto również niewielkie osuwiska (o powierzchni mniejszej niż 0,1 ha) o genezie antropogenicznej położone na obszarze miejskim. Ilościowo jest ich najwięcej. Współcześnie najbardziej aktywnym pod względem ruchów masowych brzegiem klifowym Zatoki Gdańskiej jest Cypel Redłowski. Tempo cofania wybrzeża klifowego, obliczone za pomocą naziemnego skaningu laserowego (TLS) na podstawie serii danych z lat 2010–2015, wynosi od 0 do blisko 5 m, czyli maksymalnie dochodzi do 1 m na rok. Natomiast średnie tempo erozji w latach 2010–2015 wyznaczone w odniesieniu do przebiegu górnej krawędzi Cypla Redłowskiego na odcinku pomiędzy 81,45 a 81,55 km linii brzegowej było równe 0,23 m na rok. Dla porównania, w przeszłości tempo cofania Cypla Oksywskiego charakteryzowało się większą intensywnością. Na początku XIX w. osuwisko na Cyplu Oksywskim miało katastrofalny przebieg i spowodowało całkowite zniszczenie posadowionych tam fortyfikacji. Od ponad stu lat jest ono chronione przed abrazją morską za pomocą opaski brzegowej. Osuwiska klifowe są inicjowane przez procesy abrazji morskiej, na które największy wpływ mają sztormy. Ważnym impulsem sprawczym dla ruchów masowych występujących w Gdyni są również nawalne opady deszczu o sumie dobowej przekraczającej 100 mm. Do opadów takich doszło w Gdyni w 2016 r., obserwowano wówczas wzmożone ruchy osuwiskowe, które spowodowały znaczne straty materialne.

EN

Large group of the natural coastal landslides in the area of Gdynia (Babie Doły, Oksywie and Redłowo) are dominant and cover an area of about 4 ha (i.e. 60% of the area studied). The anthropogenic landslides, on the other hand, are more numerous but not bigger than 0.1 ha and occur within the town area. Cypel Redłowski is the most active cliff of the Bay of Gdańsk. There the erosion causes significant retreat of the coastline. The pace of that backward movement calculated by means of Terrestrial Laser Scanning (TLS), between years 2010 and 2015 was between 0 to almost 5 metres. During the same time the Cypel Redłowski retreated from 81.45 to 81.55 km, i.e. at a pace of 0.23 metres a year. The pace of retreat in the Cypel Oksywski was even faster in the past. There the active landslides caused total damage of the fortifications built at the beginning of the 19th century. Prevention against landslides caused by the marine erosion has been applied for over a hundred years now. The marine erosion is the most significant trigger of the coastal landslides. The intensity of the erosion depends on the frequency of storms. Heavy rains exceeding 100.0 mm per 24 hours also trigger mass movements in the Gdynia area. Such event took place in Gdynia in 2016. At that time a landslide movement causing extensive damage was recorded.

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Aktywność procesów osuwiskowych na wybrzeżu klifowym wyspy Wolin w warunkach oddziaływania zdarzeń hydrometeorologicznych o wysokim potencjale morfogenetycznym (Zatoka Pomorska – Bałtyk Południowy)

Winowski M.

Landform Analysis

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2015

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Vol. 28

87--102

PL

Artykuł prezentuje wyniki badań nad aktywnością procesów osuwiskowych na wybrzeżu klifowym wyspy Wolin wywołanych silnymi wezbraniami sztormowymi oraz intensywnymi opadami atmosferycznymi. Badania opierały się na studium pięciu przypadków dotyczących wykształcenia lub przeobrażenia osuwisk klifowych. W wyniku przeprowadzonej analizy zaproponowane zostały wartości progowe odporności systemu stokowego na oddziaływanie takich czynników morfogenetycznych jak wezbrania sztormowe i opady atmosferyczne. W przypadku przekroczenia wymienionego czynnika wartości progowej w obrębie klifu dochodzi do wykształcenia osuwiska. Należy nadmienić, iż inicjacja procesu osuwiskowego warunkowana jest także wieloma innymi czynnikami, które najczęściej mają charakter wybitnie lokalny (morfologia, litologia, hydrogeologia, itd.). Wobec powyższego należy stwierdzić, iż przedstawione wartości progowe są wartościami koniecznymi do wystąpienia procesów osuwiskowych, jednak z uwagi na złożoność tych procesów, w niektórych przypadkach mogą one nie stanowić wartości wystarczających.

EN

The paper presents results of research on the activity of landslides on the Wolin Island cliff coast caused by storm surges and intense rainfall events. The study was based on the analysis of five cases of initiation or transformation of cliff landslides. As a result of the analysis the treshold values of storm surges and precipitation were proposed. Exceeding the threshold values results in a landslide. It should be noted that the process of landslide initiation is conditioned also by many other factors that are most often very local (cliff morphology, lithology, hydrogeology etc.). Therefore, it must be concluded that proposed threshold values are necessary for the occurrence of landslides, but due to the complexity of these processes, in some cases, they may not provide sufficient value.

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Baltic Sea coastal erosion; a case study from the Jastrzębia Góra region

Uścinowicz G., Kramarska R., Kaulbarsz D., Jurys L., Frydel J., Przezdziecki P., Jegliński W.

Geologos

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2014

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Vol. 20, No. 4

259--268

EN

The coastline in the Jastrzębia Góra area can be divided into three major zones of general importance: a beach and barrier section, a cliff section, and a section protected by a heavy hydrotechnical construction. These areas are characterised by a diverse geology and origin, and hence different vulnerability to erosion. In addition, observations have demonstrated a different pace of erosion within each zone. Based on the results obtained by remote sensing methods (analysis of aerial photographs and maps), it has been determined that the coastline in the barrier area, i.e., to the west of Jastrzębia Góra, moved landwards by about 130 m, in a period of 100 years, and 80 m over about 50 years. A smaller displacement of the shoreline could be observed within the cliff. Between the middle of the twentieth and the start of the twenty-first centuries the shore retreated by about 25 m. However, in recent years, an active landslide has led to the displacement of the uppermost part of the cliff locally up to 25 m. Another issue is, functioning since 2000, a heavy hydrotechnical construction which has been built in order to protect the most active part of the cliff. The construction is not stable and its western part, over a distance of 50 m, has moved almost 2 m vertically downwards and c. 2.5 m horizontally towards the sea in the past two years. This illustrates that the erosional factor does not comprise only marine abrasion, but also involves land-based processes determined by geology and hydrogeology. Changes in the shoreline at the beach and barrier part are constantly conditioned by rising sea levels, the slightly sloping profile of the sea floor and low elevation values of the backshore and dune areas. Cliffs are destroyed by mass wasting and repetitive storm surges that are responsible for the removal of the colluvium which protects the coast from adverse wave effects. Presumably, mass movements combined with groundwater outflow from the cliff, plus sea abrasion cause destabilisation of the cliff protection construction.

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Geomorfologiczne skutki tajania pokrywy śniegu na wybrzeżu klifowym wyspy Wolin

Winowski M.

Landform Analysis

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2008

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Vol. 9

222--225

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Probabilistic prognosis of cliffslide along baltic sea coast in Poland

Brzozowski T., Tejchman A.

Studia Geotechnica et Mechanica

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2003

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Vol. 25, nr 1-2

135-144

EN

In recent years, an increasing activity of sliding process in many parts of Polish cliff coast has been observed. It has created a serious danger for all structures located nearby. In order to explain the mechanisms governing sliding process as well as to elaborate calculation stability methods appropriate for these mechanisms, comprehensive investigations have been undertaken. Slope stability is usually analysed by means of deterministic approach. However, such methods are insufficient for determination of stability of cliffs and dangerous zones along the cliff coastline. In the paper, a probabilistic method of cliff sliding prognosis is presented. In the method proposed, soil strength parameters are assumed to be random values. Abrasive activity of a sea is simulated by changes of cliff profile. Numerical calculations based on the method allow verification of cliff stability and evaluation of the range of failure zone in the inland part of cliff.