Wyniki wyszukiwania - Biblioteka Nauki

Ten serwis zostanie wyłączony 2025-02-11.

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

Znaleziono wyników: 4

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: coastal morphology

Sortuj według:

Ogranicz wyniki do:

Impact of cloud cover on local remote sensing – Piaśnica River case study

100%

Paszkuta M.

Oceanological and Hydrobiological Studies

2022

tom Vol. 51, No. 3

283--297

New satellite-based techniques open up new horizons to researchers and local communities. Concurrently, however, requirements and expectations with regard to satel-lite-based remote sensing products are increasingly higher. By relying on satellite-derived information, environmental observations can cover areas of a few to several metres resolution. Here we are dealing with free-of-charge and generally available sources of satellite-based information. The Piaśnica River mouth area was selected as an observation site representing a highly dynamic morphological transect. The paper compares products of cloud cover detection, supplied with data and available in the Copernicus database for a local area in the coastal zone of the Baltic Sea. The absolute difference did not exceed 5%, which confirms a high efficiency of the solutions offered. More than 96% of the clouded area determined for the Sentinel-2/MSI (Multispectral Instrument) was correctly identified when compared with supervised observations. The rate was lower (92%) for the Sentinel-3/OLCI (Ocean and Land Colour Instrument). It was eventually concluded that, at the local level, successful observations can be conducted using the cloud cover map supplied with the satellite data. At the same time, the analyses presented do not rule out further efforts to, e.g., increase the accuracy and speed of the analyses.

Local Wave Energy Dissipation and Morphological Beach Characteristics along a Northernmost Segment of the Polish Coast

100%

Różyński G.

Archives of Hydro-Engineering and Environmental Mechanics

2018

tom Vol. 65, nr 2

91--108

This paper analyses cross-shore bathymetric profiles between Władysławowo (km 125 of the Polish coastal chainage) and Lake Sarbsko (km 174) done in 2005 and 2011. Spaced every 500 m, they cover beach topography from dune/cliff crests to a seabed depth of about 15 m. They were decomposed by signal processing techniques to extract the monotonic component of beach topography and to perform a straightforward assessment of wave energy dissipation rates. Three characteristic dissipation patterns were identified: one associated with large nearshore bars and 2–3 zones of wave breaking; a second, to which the equilibrium beach profile concept can be applied; and a third, characterized by mixed behaviour. An attempt was then made to interpret these types of wave energy dissipation in terms of local coastal morphological features and the underlying sedimentary characteristics.

Some characteristic wave energy dissipation patterns along the Polish coast

100%

Różyński G. , Szmytkiewicz P.

Oceanologia

2018

tom No. 60 (4)

500--512

The paper analyses cross-shore bathymetric profiles between Władysławowo (km 125 of the national coastal chainage) and Lake Sarbsko (km 174) commissioned in 2005 and 2011 by coastal authorities for monitoring purposes. The profiles, spaced every 500 m, cover beach topography from dune/cliff tops through the emerged beach to a seabed depth of about 15 m. They were decomposed by signal processing techniques to extract their monotonic components containing all major modes of the variability of beach topography. They are termed empirical equilibrium profiles and can be used for straightforward assessment of wave energy dissipation rates. Three characteristic patterns of wave energy dissipation were thus identified: one associated with large nearshore bars and several zones of wave breaking; a second, to which the equilibrium beach profile concept can be applied; and a third, characterized by mixed behaviour. Interestingly, most profiles showed significant seabed variations beyond the nearshore depth of closure – this phenomenon requires comprehensive studies in future.

High-energy, microtidal nearshore deposits and their provenance (Lower Miocene, Burdigalian/Eggenburgian, Alpine-Carpathian Foredeep, Lower Austria)

86%

Nehyba S. , Roetzel R.

Geological Quarterly

2022

tom Vol. 66, No. 4

art. no. 33

During the Early Miocene (Early Burdigalian/Eggenburgian) marine transgression at the southeastern margin of the Bohemian Massif, gradual flooding occurred along a rocky coast on granitic bedrock of the Thaya Batholith under high-energy, wave-dominated, microtidal and mixed fair-weather and storm conditions. Deposits of the Burgschleinitz Formation overlie a basal unconformity above a subaerial weathered basement surface (transgressive erosional surface) and are interpreted as a transgressive systems tract. The deposits can be divided into four facies associations/depositional environments, i.e., upper-shoreface, foreshore, gravelly beach and backshore/lagoon. Two stages of transgression and successive overtopping of the basement, with different coastal physiographies, were documented. During the initial stage of transgression a barrier island system developed with relatively fine-grained deposits, reflecting the flooding of the distant parts of the Thaya Batholith with a relative flat basement morphology. The subsequent continuation of the transgression led to the flooding of the more proximal parts of the Thaya Batholith with a steeper relief and formation of a rocky shoreline with deposition of gravelly sedi- ments along palaeo-sea cliffs or wave-cut platforms. While gravel clasts of the deposits investigated originate directly from the underlying granites of the Thaya Batholith, provenance studies show that metamorphic rocks of the Moravian Superunit in the hinterland were the main source of sands. This distant source material was probably delivered mainly by small creeks and alluvial fans to the nearshore. Significant differences in heavy mineral composition of the same formation in the wider vi cinity indicate primarily local sources and rapid deposition with subordinate longshore transport, which may reflect a complex coastal palaeogeography. The Lower Miocene deposits of the Burgschleinitz Formation investigated are a rare example of ancient rocky shore deposits, which generally have low preservation potential in the geological record.