The studies described herein aimed to estimate the accuracy of determination of the volumetric changes on the dune coast of the southern Baltic Sea through the application of the XBeach numerical model, which is crucial for coastal engineering. In the first phase of the study, the profile (1D) mode of the model was adapted to 19 cross-shore profiles located along the Dziwnów Spit. The model was calibrated with a storm event in 2009 that caused significant changes to dunes and beaches. Cross-shore profiles were measured approximately one and a half months before and after the storm. An evaluation of model performance was made based on the Brier skill score (BSS), the visual match of the profile shape (VMS), the absolute volumetric change error (m3/m) and the relative volumetric change error (%). In this study, parameters related to the asymmetry transport (facua) and the dune erosion algorithm (wetslp) were taken into account. The best results for model calibration on all 19 cross-shore profiles were obtained with facua values ranging from 0.16 to 0.40 and wetslp values from 0.35 to 0.60. The calibration of individual profiles yielded good results, with an average absolute error of approximately 4 m3/m and an average relative error of ca. 20%. The poorest results were collected for the profiles situated near coastal engineering structures, where the average absolute error was 10 m3/m and the relative error was 60%. The possibility of accepting one set of parameter values for all the profiles at once was also investigated. These studies revealed that the application of one set of facua and wetslp values for all profiles simultaneously resulted in a relative volumetric change error of ca. 25% on average, with the maximum of about 40%. Due to the difficulty of collecting data just before and after the storm event, complex studies using all available bathymetric data were performed. Using a joint dataset composed of prestorm topography recorded before that storm and bathymetry from different years, a simulation of the 2009 storm event was carried out. The studies revealed that the prestorm bathymetry and the randomness of the selection of calibration parameters have similar effects on the accuracy of volumetric changes. Moreover, the impact of the nearshore bathymetry (to a depth of 2 m) on modeling the volumetric changes in the terrestrial part of the shore is evident. A change in the sea bottom inclination and a successive change in the nearshore sediment volume can increase the difference between modeled and actual volumetric changes.
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Due to the rising environmental awareness, emissions and releases of pollutants, including metals, have been considerably reduced in the last decades. Therefore, the remobilization of natural and anthropogenic contaminants is gaining importance in their biogeochemical cycle. In the marine coastal zone, this process occurs during the erosion of a shore, especially the most vulnerable cliffs. The research was conducted in the Gulf of Gdańsk (southern Baltic Sea) from 2016 to 2017. The sediment cores were collected from four cliffs; additionally, marine surface sediments were also taken. The concentrations of essential (Cr, Mn, Fr, Cu, Zn) and nonessential (Rb, Sr, Y, Zr, Ba) metals were analyzed using the XRF technique. The levels of the analyzed metals were relatively low, typical of nonpolluted areas. However, considering the mass of eroded sediments, the annual load of metals introduced into the sea in this way is significant. In the case of Cu, Zn, and Y the load can amount to a few kilograms, for Cr and Rb – over ten kilograms, for Mn, Sr, and Zr – several tens of kilograms, for toxic Ba – over 100 kg, and in the case of Fe – 4.8 tonnes. During strong winds and storms, when the upper part of a cliff is eroded, especially the load of Zn and Cr entering the sea may increase. The content of Cr, Zr, and Ba in the cliffs was higher compared to marine sediments from the deep accumulation bottom, which indicates that coastal erosion may be an important source of these metals.
Timbulsloko is a village on the coast of Sayung District, Demak Regency that is severely affected by coastal erosion. The coastal erosion in the Timbulsloko Village is mainly caused by the removal of mangrove areas, which has eliminated the function of the natural breakwater for the coast of the Timbulsloko Village. This study aimed to mitigate the coastal erosion in the form of structural and non-structural protection. Structurally (physically), mitigation is conducted by protecting the coastal area with the application of environmentally friendly coastal protection technology in the form of a Permeable breakwater with a Hybrid Engineering structure. Furthermore, the effectiveness of two different structure segments in damping waves from September 2020 – March 2021 will be measured. In contrast, non-structurally, mitigation is conducted in a non-physical way by analyzing the Coastal Vulnerability Index of Timbulsloko Village based on the parameters of Coastal Typology, Average Tidal Range, Significant Wave Height, Coastal Slope, Coastal Geomorphology, Sea Level Rises, and Shoreline Displacement using the CVI method. The effectiveness of the permeable structure’s wave damping is determined by the initial wave height and transmission wave height measured by the ultrasonic sensor. On the basis of segment differences, the Permeable Breakwater Segment 2 with a distance between bamboo of 0.25 m has better effectiveness than a Permeable Breakwater Segment 1 with a distance between bamboo of 0.5 m. The results of the Coastal Vulnerability Analysis show that the Timbulsloko Village is vulnerable to coastal disasters, especially coastal erosion.
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The serious destruction of resources and environment in Laizhou Bay has attracted extensive attention of researchers. This study mainly analysed the changes of fish structure and environment in the coastal zone of Laizhou Bay caused by human activities. By consulting literatures and field measurements, the changes of dominant fish species, coastline and sea water intrusion were analysed. The results showed that dominant fish species in Laizhou Bay change from high-economic species to low-economic species under the influence of human activities, and the coastline erosion was serious, and the area of sea water intrusion was also increasing year by year. It is concluded from the research results that human activities had a significant impact on the structure of fish school and the environment. It is necessary to arrange human activities in an appropriate amount to reduce the overexploitation of resources in order to restore the fishery resources and environment in Laizhou Bay.
Beach sands from the Rosa Marina locality (Adriatic coast, southern Italy) were analysed mainly microscopically in order to trace the source areas of their lithoclastic and bioclastic components. The main cropping out sedimentary units were also studied with the objective to identify the potential source areas of lithoclasts. This allowed to establish how the various rock units contribute to the formation of beach sands. The analysis of the bioclastic components allows to estimate the actual role of organisms regarding the supply of this material to the beach. Identification of taxa that are present in the beach sands as shell fragments or other remains was carried out at the genus or family level. Ecological investigation of the same beach and the recognition of sub-environments (mainly distinguished on the basis of the nature of the substrate and of the water depth) was the key topic that allowed to establish the actual source areas of bioclasts in the Rosa Marina beach sands. The sedimentological analysis (including a physical study of the beach and the calculation of some statistical parameters concerning the grain-size curves) shows that the Rosa Marina beach is nowadays subject to erosion.
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.
Od 2010 r. w Państwowym Instytucie Geologicznym – Państwowym Instytucie Badawczym jest wdrażana technologia naziemnego skaningu laserowego do monitorowania procesów geodynamicznych zachodzących na klifowych odcinkach polskiego brzegu Bałtyku. Przedstawiono metodę wykonania pomiarów za pomocą impulsowego skanera laserowego Riegl VZ-400 oraz analizę danych na przykładzie klifu Jastrzębiej Góry. Pomiary poszczególnych odcinków klifu, wykonywane od kwietnia 2010 do marca 2011 r., wykazały zróżnicowane tempo erozji. Zachodni segment masywnej zabudowy zbocza uległ odkłuciu od ściany klifu i przesunięciu o prawie 1 m w pionie i około 1,2 m w kierunku morza. Czynne osuwisko w centralnej części badanego odcinka spowodowało cofnięcie brzegu o około 10 m i ubytek mas ziemnych o ponad 4000 m3. We wschodniej części odcinka, na makroskopowo stabilnym koluwium, stwierdzono przesunięcia drzewostanu o około 1 m. Uzyskane wyniki są początkiem bazy danych morfometrycznych pozyskanych metodą naziemnego skaningu laserowego.
EN
Since 2010, the Polish Geological Institute – National Research Institute has implemented the use of Terrestrial Laser Scanning (TLS) for geodynamical processes monitoring of backshore parts of the Polish coastal zone. This article describes the methodology of TLS surveying, using Riegl VZ-400 ground-based laser scanner. The analyzed data originates from Jastrzębia Góra cliff. Coastal surveying, launched in April 2010 (ended in March 2011), showed diverse erosion rates. Western part of the Massive Cliff Stabilization System had split from the cliff face and advanced ca. 1.2 m seawards, together with nearly 1 m vertical displacement. An active landslide in the central coast section, caused shore retreat by 10 m and land loss of 4000 m3. In the eastern part, within the macroscopically stable colluvium, a shift of the forest stand of approximately 1 m was detected. The obtained data forms the basis of the morphometric database acquired by TLS.
The geohazards – floods, hurricanes, earthquakes, volcanic eruption, tsunamis, mass movements, avalanches etc. are reasons of many catastrophes and tragedies in the scale of our Globe. Thanks to the geographical position of Poland, it is missing at the list of the biggest natural disasters in the XX century. A breakthrough moment for awakening of social consciousness in relation to natural catastrophes happened in summer 1997. At that time the catastrophic regional flood took place in the Odra River and affected substantial areas in Poland, and other countries of Central Europe innundaing many towns and villages. Over 100 people were killed and material losses were counted in millions of dollars. Soon after the flood, the enormous amounts of landslides were activated, mainly in the Carpathians. The list of the main geohazards in Poland includes: mass movements, coastal erosion, soil erosion and floods. Geohazard phenomena are measured and monitored by different means, mainly precise levelling, GPS and other geodetic methods. In the last years the new technology appeared – Persistant Scatterer Interferometry (PSI), based on the remote sensing radar satellites. The technology uses the data collected by European Radar Satellites (ERS-1, ERS-2 and ENVISAT) in a process called Synthetic Aperture Radar Interferometry, or PSI for short. PSI can cover whole cities and regions, and because an archive exist of "repeat" satellite data, measurements can uniquely be provided back in time for the last twelve years. It will be effective operative tool for geohazards monitoring in the nearest future.
PL
Geozagrożenia, takie jak powodzie, huragany, trzęsienia ziemi, wulkanizm, tsunami, powierzchniowe ruchy masowe itp., są przyczyną wielu katastrof i tragedii w skali całej naszej planety. Dzięki usytuowaniu geograficznemu i geologicznemu, Polska szczęśliwie nie znajduje się na liście krajów, w których w XX wieku miały miejsce wielkie naturalne katastrofy przyrodnicze. Przełomowym momentem dla obudzenia świadomości społeczeństwa w odniesieniu do katastrof przyrodniczych były wydarzenia, które wystąpiły latem 1997 r. W tym okresie miała miejsce katastrofalna powódź regionalna na Odrze i jej dopływach, która zalała wiele miast i wiosek w Polsce i przyległych krajach oraz spowodowała śmierć ponad 100 osób i ogromne straty materialne. Wkrótce potem zaktywizowały się na ogromną skalę osuwiska, głównie w Karpatach. Lista głównych zagrożeń w Polsce obejmuje: powierzchniowe ruchy masowe, erozję brzegową, erozję gleb oraz powodzie. Geozagrożenia są identyfikowane i monitorowane przy pomocy różnych metod: niwelacji precyzyjnej, lokalizatorów GPS i innych metod geodezyjnych. W ostatnich latach doszła nowa metoda, PSI – Satelitarna Interferometria Radarowa (wykorzystująca ciągłe punkty pomiarowe). Metoda ta bazuje na danych z europejskich satelitów radarowych (ERS-1, ERS-2 oraz ENVISAT) oraz wykorzystuje analizę interferometryczną – PSI. PSI może objąć analizą znaczne obszary, a istnienie archiwalnych danych radarowych umożliwia przeprowadzenie studiów w ciągu ostatnich 12 lat. W niedługiej przyszłości PSI będzie jedną z głównych operacyjnych metod dla detekcji i monitorowania geozagrożeń.
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Evaluation of erosion threats was the main aim of the European Commission project called EUROSION. To fulfill this task many European programs and plans for coastal management were reviewed. Geographic Information Systems were present in all of them as one of the most important tools. Based on that experience some recommendations for designing a dedicated system were prepared. Another project MESSINA - .Managing European Shoreline and Sharing Information on Near-Shore Areas. was aimed at implementation of those recommendations and their verification. The Laboratory of Remote Sensing and Marine Cartography localized at the University of Szczecin was responsible for collecting data and implementing it into comprehensive GIS system for the Rewal community within the MESSINA Project. The main emphasis was placed on erosion problems and hazards of a long term near-shore investment connected with this issue. Many sets of data both graphic and attribute ones were collected for the pilot area of the Rewal community. The data reaching back even to year 1933 consisted of archival and present raster and vector maps, pictures, high resolution space images, coefficients of erosion rate and future investment plans up to 2015. All data was organized in one coordinate system with the use of ArcGIS software and presented in a way to enable display and analysis of plots and their development over any other available data. Calculation of shoreline changes was based on coefficients of erosion rate and prepared with the use of buffering tool leading to results of predicted changes that are supposed to occur in 20, 50 and 100 years. All analyses were conducted in two different scenarios. One assuming that the cliff where ruins of Trzęsacz church are standing will be protected and the second one assuming no human interference. To automate this time-consuming analyzis a Model Builder module was used. Both scenarios representing different changes of the coastline included two different forecasts. Depending on the erosion rate we can call them optimistic and the second one is a pessimistic forecast. Beside the value of erosion range and information about parcels spatial distribution both scenarios include estimated losses for each plot. Also parts that are not under any threats within the period of 20, 50 or 100 years are available for display. All results can by compared with the investment plans and for better perception they may be strengthened with the remote sensing data displayed below the basic information. This effective tool created within the MESSINA Project to predict shoreline behavior can be used in the decision making process by the community council. Additionally, the created system was used to explain complicated shoreline issues and its results in social consultations.
Polish coast of the Baltic Sea has a total length of 498 km (without internal lagoons coasts). Quaternary deposits dominate coastal zone, similar to central and northern Poland. According to morphology and geological structure, three types of coast are distinguished: cliffs (c. 101 km), barriers (380 km) and coast similar to wetlands (salt marshes) (c. 17 km). Generally, three types of mass movements can be distinguished on cliff coast: eboulements (rock falls) dominated on the cliffs built mainly by tills, talus and landslip, dominated on sandy cliffs, and typical landslides occurred on cliff stretches with a complex structure where the main role play clay layers being initial slide layers for other deposits. Serious risks are related to erosion of low and narrow barriers, which could be easy broken during storm surges. Storm floods in case of barrier being broken threaten lowlands behind the barriers. Similar flood hazard exists also on lagoon coasts located behind large and relatively stable barriers. It is caused by barographic high water stands, which in extreme cases reach up to 2 m above the mean sea level, and water back flow into straits connecting lagoons with the sea.
PL
Długość polskiego wybrzeża morskiego wynosi 498 km (bez linii brzegowej Zalewów Wiślanego i Szczecińskiego). W budowie geologicznej strefy brzegowej, podobnie jak środkowej i północnej Polski, dominują osady czwartorzędowe. Biorąc pod uwagę geomorfologię i budowę geologiczną wyróżniono trzy zasadnicze typy wybrzeży: klify o łącznej długości ok. 101 km, wybrzeża wydmowe (mierzeje) o łącznej długości ok. 380 km oraz wybrzeża nizinne typu Wetland o długości ok. 17 km. Na wybrzeżach klifowych wyróżniono trzy typy ruchów masowych: obrywy dominujące na klifach, w których występuje glina zwałowa, zsuwy i osypiska dominujące na klifach zbudowanych głównie z osadów piaszczystych oraz typowe osuwiska występujące na klifach o złożonej strukturze geologicznej, gdzie główną rolę odgrywają warstwy ilaste będące powierzchnią poślizgu dla warstw wyżej ległych. Poważne zagrożenia związane są też z erozją niskich i wąskich mierzei, które łatwo mogą być przerwane w czasie sztormów. Nisko położone obszary zaplecza mierzei w takim wypadku zagrożone są powodziami sztormowymi. Podobne zagrożenia powodziowe istnieją też na zapleczu mierzei relatywnie stabilnych - szerokich z wysokimi wałami wydmowymi. Powodzie mogą wystąpić w przypadku wysokich stanów wody spowodowanych spiętrzeniami sztormowymi i barycznymi, dochodzącymi maksymalnie do 2 m ponad średni poziom morza, kiedy dochodzi do wlewów wód morskich do Zalewów i jezior przybrzeżnych.
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