Wszystkie pola: morphodynamic area - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: State of shore and backshore on the basis of monitoring results for selected polish seashores
Stan brzegu i nadbrzeża na podstawie wybranych wyników monitoringu polskich brzegów morskich
Autorzy:: Boniecka, H.
Kaźmierczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/111581.pdf
Data publikacji:: 2015
Wydawca:: Instytut Morski w Gdańsku
Tematy:: beach
backshore
dune
cliff
sandbar
spit
morphodynamic area
morphometric parameters
hydrodynamics
plaża
nadbrzeże
wydma
klif
mierzeja
rejony morfodynamiczne
parametry morfometryczne
hydrodynamika
Opis:: Aim of works on morphology and morphometry of the coastal zone is identification of qualitative and quantitative changes in the beach-dune strip and in the shoreface in conditions of their natural and anthropogenic transformations. As shore and backshore are essential elements reducing risks from the sea to the adjacent hinterland, this article focuses on evaluation of their parameters. Moreover, elements of the coast are described herein in detail. The research material used for the purposes of this article were records of bathymetric-tacheometric measurements of the Polish coast, made at consistent profiles evenly spaced every 500 m. The measurements did not cover the areas adjacent to the Bay of Gdańsk or the Lagoons. This article presents an analysis of the measurements of components of the coastal zone, which covered four morphodynamical areas (the Hel Peninsula, Jastrzębia Góra – Jarosławiec, Jarosławiec – Sarbinowo, and Sarbinowo – Międzyzdroje), twelve sandbar stretches (the Helska, Karniewska, Sarbska, Łebska, Długie, Gardno, Wicko, Kopań, Bukowo, Jamno, Resko, and Dziwnowska Spits) and thirteen cliff stretches (the cliffs in Chłapowo, Jastrzębia Góra, Rowy, Dębina, Ustka, Jarosławiec, Wicie, Sarbinowo, Ustronie Morskie, Śliwin, Trzęsacz, Pobierowo, and on Wolin Island). The basic linear parameters of the beach-dune and beach-cliff belt were read from 678 printouts of tacheometric profiles. A detailed analysis carried out in this manner made it possible for the endangered sections of the coast to manifest themselves. The obtained data are a basis for further comparative analyses, and assessment of the shore under conditions of implementation of the Act on the Protection of Sea Coasts.
Celem prac nad morfologią i morfometrią strefy brzegowej jest poznanie jakościowych i ilościowych zmian zachodzących w pasie plażowo-wydmowym i na podbrzeżu w warunkach ich naturalnych i antropogenicznych przekształceń. W artykule skupiono się na ocenie parametrów brzegu i nadbrzeża, jako znaczących elementów redukujących zagrożenie przyległego zaplecza od strony morza. Ponadto opisano szczegółową charakterystykę elementów wybrzeża. Materiałem badawczym były zapisy pomiarów batymetryczno-tachimetrycznych polskiego wybrzeża, w stałych profilach rozmieszczonych co 500 m. Pomiary nie objęły swoim zasięgiem obszarów przylegających do Zatoki Gdańskiej czy zalewów. W artykule przedstawiono analizę pomiarów elementów strefy brzegowej, które objęły cztery rejony morfodynamiczne (Półwysep Hel, Jastrzębia Góra- -Jarosławiec, Jarosławiec-Sarbinowo oraz Sarbinowo-Międzyzdroje), dwanaście odcinków mierzejowych (Helska, Karniewska Sarbska, Łebska, Długie, Gardno, Wicko, Kopań, Bukowo, Jamno, Resko i Dziwnowska) i trzynaście odcinków klifowych (chłapowski, jastrzębski, rowski, dębski, ustecki, jarosławiecki, wicki, sarbinowski, ustroniomorski, śliwiński, trzęsacki, pobierowski i woliński). Na wydrukach 678 profili tachimetrycznych odczytano podstawowe parametry liniowe pasa plażowo-wydmowego i plażowo-klifowego. Tak przeprowadzona szczegółowa analiza wybrzeża pozwoliła na uwidocznienie zagrożonych odcinków. Uzyskane dane stanowią podstawę do dalszych analiz porównawczych i oceny stanu brzegu w warunkach wdrażania zapisów ustawy o ochronie brzegów morskich.
Źródło:: Biuletyn Instytutu Morskiego w Gdańsku; 2015, 30, 1; 150-163
1230-7424
2450-5536
Pojawia się w:: Biuletyn Instytutu Morskiego w Gdańsku
Dostawca treści:: Biblioteka Nauki

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Tytuł:: Procesy morfodynamiczne w zlewni gównej amazonki w świetle urzeźbienia powierzchni ziarn kwarcowych w mikroskopie elektonowym
Morphodynamic processes in the catchment area of the upper amazon in the light of the surface relief of quartz grains in the electron microscope
Autorzy:: Makowski, J.
Mycielska-Dowgiallo, E.
Powiązania:: https://bibliotekanauki.pl/articles/2085669.pdf
Data publikacji:: 1988
Wydawca:: Uniwersytet Warszawski. Wydział Geografii i Studiów Regionalnych
Tematy:: procesy morfodynamiczne
rzeka Amazonka
zlewnie
rzezby
powierzchnia
ziarna kwarcowe
mikroskop elektronowy
Ameryka Poludniowa
Opis:: The article concerns the results of investigations of the surface relief of quartz grains in two samples of deposits coming from the upper part of the Amazon catchment area, presented in conditions of the natural environment prevailing nowadays and in those of the Pleistocene epoch. The analysis of the greatly magnified sand grains surface was done in a scanning electron microscope of the ISM-25 Jeol type, in the Institute of Geology, Warsaw. The samples of deposits were collected during field investigations in Peruvian Amazonia, in the summer of 1980. The first of the samples comes from the Huallaga valley (right tributary of the Maranón) near the town of Tingo María. It is an area of a warm and humid climate (over 3000 mm of precipitation per year) with intensive processes of chemical weathering, especially among limestone mountain massifs strewn with caves. Even in close proximity of Tingo María the climate is much differentiated; in the neighbouring Huánuco valley, crossed by the Huallaga river, precipitation does not exceed 400 mm yearly and the mountain-slopes are not densely covered with vegetation. The bottom of the Huallaga valley, the mid-channel and coastal sand-banks are built of thick, ill-sorted material containing pebbles, gravel and various-grain sands. The same material may be observed in the exposures of the river’s gorge section (between Huánuco and Tingo María), where it forms high terrace horizons now intensively destroyed by stone-falls and landslides. A cold and humid climate prevailed in the Andes in the glacial epoch. The Central Andes were then glaciated twice at least, and the traces of glaciation such as moraines and post-glacial lakes are common in the upper sections of river valleys of that region. Glaciers developed probably also in the Huallaga valley (above Huánuco) and in the upper parts of the valleys of some of its tributaries. It was probably at that time that the valleys of the Central Andes were highly filled up and among them the Huallaga valley in its gorge section. The analysis of the surface relief of quartz grains in the scanning microscope, by 400-1500 x magnification, has allowed to recognize the character of grain-forming processes and the order of their action. Smooth surfaces have conchoidal breakage with bunches of steps and block relief (Pl. I, photo 4, Pl. II. photo 1). On weathered surfaces there occur fragments covered with a crust (Pl. II, photo 2) which is an indication of dry climate in which silica and other minerals could be precipitated on the grain surface. Other fragments show forms directed in accordance with the crystallographic lattice which points to chemical etching processes (Pl. II, photo 3). There occurs sporadic „lichen” - type chipping (Pl. II, photo 4) observed in areas of intensive mechanical weathering. If more magnified (1500-5000 X) the surfaces modelled by weathering processes display deep corrosive pits (Pl. III, photo 1) frequently having a crystal-directed form (Pl. III. photo 2) and secondary crystallization on the surface. The alternation of the relief types allows to infer on the order in which the processes acted. Three stages may be distinguished: 1) intensive weathering in changing climatic conditions (humid, dry; of high and low temperature); 2) mechanical destruction of the grains; 3) renewed processes of chemical weathering. The time interpretation of those facts presents many difficulties. It cannot be excluded that the glacial period is indirectly recorded in the stage of intensive disintegration of quartz grains, separating two periods of active weathering processes. Thus the glaciation period would be preceded by a period of very dry climate and by another - of great humidity and presumably of high temperature. Uncluckily it is impossible to infer on the succession of those processes by the remaining forms of relief. The post-glacial period was marked only by chemical weathering. However, another origin of the fresh structures preserved on grain surfaces cannot be excluded. In strongly dynamic rivers, carrying masses of pebbles, quartz grains may undergo grinding and trituration like in rock mills. Thus the sharp-edged forms preserved on grains may be as well as relict of the time of flow of fluvioglacial water as they may be shaped at present in highly dynamic rivers to which the Huallaga belongs. The other sample of deposits comes from the Amazon Lowland. It was collected from the edge of a mid-channel sand-bank in the Amazon valley, near Iquitos. The place of collection lies ca 130 km below the confluence of the Ucayali and the Maranón. In this part of the Amazonia a humid, equatorial climate prevails, the mean temperature being 25°C and the precipitation - 2500 mm yearly. It is a low-lying and relatively flat area. The small differentiation of relief is connected with a relatively simple geological structure. Vast plateaux are built of terrigenic formations of the Upper Tertiary (Pebas Formation) and of younger deposits dating from the end of the Tertiary and the beginning of the Quaternary (Iquitos Formation) filling the valley-like depressions cut in older formations. Quaternary and contemporary deposits fill the valleys and build terrace horizons. It is very difficult to define precisely the age of Quaternary acumulation horizons. The phase of intensive erosion in the Amazon valley which descended, along the section from the river mouth to Manaus (1500 km), much below the present-day sea level, is connected with the period of pre-Flandrian regression corresponding with the Vistula glaciation. The climate of the present-day Amazonia was then drier than nowadays. In place of the now existing forests (selva) there grew a savannah with small spots of forests in more humid habitats. At that time, in the Andes foreland, there may have occurred the accumulation of large cones and terrace horizons. The formation of the flood-plain terrace (3-8 m high) in the Ucayali and the Amazon valleys can be probably connected with that period. Similar conditions must have prevailed in the farmer glaciation (the Riss) and the above-floodplain terrace (10-12 m high) could have been formed then. The rise of the ocean level in the Holocene (Flandrian transgression) and a more humid climate caused the expansion of forests and the set-back of erosion. A negative balance of alluvia due to dense vegetation did not allow the deposits to fill the Amazon valley in its lower part; moderate erosion cannot be excluded in the river’s upper part. Among the present-day processes modelling the relief in the river valleys, beside fluvial processes, the activity of the wind should be mentioned, which makes the water wave. This process is favoured by the considerable width of rivers and the existence of numerous overflow arms. The results of waving, such as beaches and cliffs reaching 1.5 m of height, can be seen on both sides of the river bed. Strong waving is also caused by the movement of boats. The analysis of quartz grains of the second sample has shown essential differences in the character of the relief forms of the grain surface as compared with the sample from the Huallaga valley. By 400 X magnification monadnock relief connected with weathering processes, and smooth, rounded edges (Pl. IV, photo 3) may be observed. Larger magnification (2000-7000 X) allows to interpret the relief type in its genetic sense and to connect it with appropriate processes. The oldest process recorded on the grain surface was that of precipitation of amorphous silica forming crusts (Pl. IV, photo 4, Pl. V, photo 1). It may be the record of weathering processes in dry, continental climate of the last glaciation. Another type of forms occurring on all the grains under investigation are V-shaped cuts chaotically disposed (Pl. VI, photos 3, 4, Pl. VII, photos 1, 2), characteristic of beach environment. Some of the V-shaped forms have developed on crust-covered surfaces, some - on fresh surfaces. At times accumulations of V-shaped forms may be observed together with crescent-shaped cuts (Pl. VII, photos 3, 4) which might indicate beach environment where intensive processes of chemical weathering cooperate. It may be supposed that both types of forms (forms connected with chemical weathering and forms developed through abrasion caused by waving) develop nowadays in the region of the upper Amazon. Waving and great changes of water level over the year cause strong side-erosion of higher terraces. This may explain the occurrence, in the alluvia, of crust-covered grains which probably lie on a secondary deposit.
Źródło:: Prace i Studia Geograficzne; 1988, 09; 141-175
0208-4589
Pojawia się w:: Prace i Studia Geograficzne
Dostawca treści:: Biblioteka Nauki

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Tytuł:: Coastal morphodynamics associated natural hazards: a case study of Oluvil area in Ampara district, Sri Lanka
Autorzy:: Nijamir, K.
Kaleel, M. I. M.
Powiązania:: https://bibliotekanauki.pl/articles/1177917.pdf
Data publikacji:: 2018
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:: GIS
Tidal action
biodiversity
littoral change
morphodynamic
natural hazard
Opis:: The tidal action is one of the most significant forces of the littoral changes. This study mainly focuses on coastal morphodynamics associated hazards which are caused by the natural phenomena. The study area, which is covered about 16 km in length, is rich by coastal resources and has an abundance of natural biodiversity. The objectives of this study (a) to identify the coastal morphodynamics associated hazards by the waves in the study area and (b) to detect coastal morphodynamics using time series data from 1981 to 2015 and to show the intensity of shoreline changes with the aid of Geo Spatial Technology. For this study, Aerial photograph in 1981 and satellite images of 2001 and 2015 used to identify the costal morphodynamics of the study area and they were subjected to the analysis with the aid of GIS 10.5 software. This study is concluded that the coastal morphodynamics associated hazards have been identified heavily in the study area due to the severe wave action.
Źródło:: World Scientific News; 2018, 97; 113-124
2392-2192
Pojawia się w:: World Scientific News
Dostawca treści:: Biblioteka Nauki

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