Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 5

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  DSAS
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
Coastal zones, as highly dynamic and complex environments, have substantial ecological and territorial implications for both government authorities and coastal managers. This research study investigated the impacts of port construction on shoreline dynamics along the coastal region of Ksar Esghir, located on the northern coast of Morocco, over a 19-year period (2002–2021). This study aimed to characterize the evolution of the coastline using high-resolution satellite images in a geographic information system (GIS) environment. Coastline evolution was assessed using GIS tools, particularly the digital shoreline analysis system (DSAS). Statistical approaches were used to determine the net rates of shoreline change, namely the end point rate (EPR) and net shoreline movement (NSM). Three main sectors were defined for the study area: The Eddallya sector, the western sector of Ksar Esghir and the port sector. As a result, two distinct zones have been identified in the Eddallya sector. Zone I shows an average accretion of +1.46 m/year, while zone II shows an erosion of -0.80 m/year. Analysis of the western sector of Oued Ksar Sghir revealed both erosion and accretion sites. Furthermore, the port sector showed positive values for shoreline evolution, with an average of +9.44 m and a rate of +0.49 m/year, signifying significant shoreline expansion over the study period. These findings highlight the dynamic and highly complex processes involved in coastal development in the study area. The results suggest that sediment dynamics, tidal regimes and potential anthropogenic influences have a significant impact on shoreline evolution, especially where port construction is concerned. The outcomes of this study provide helpful information for better and sustainable coastal management along the coastal area of Ksar Sghir.
EN
The aim of the paper is to identify a methodology capable of assessing shoreline changes through a geomatic approach based on the use of GIS (Geographic Information System) software. The paper describes a case study that reports the evolution of a coastline over a period of more than 100 years using medium and large-scale metric maps available in different periods. In fact, the coastlines were obtained from the source maps of the Italian Cadastre (dated 1890), from numerical cartography available on the coastline and acquired in different period at scales 1:5000 and 1:2000 and, more recently, from the Google Earth Pro platform. To analyse the evolution of the coastline a new procedure has been performed which is based on the use of GIS software, in particular a plugin called DSAS that allows the evaluation of the changes in the coastline and also obtains a statistical analysis of its evolution. The results showed the ease and applicability of the method in determining the evolution of the coastline and the strong erosion of a stretch of coastline with important socio-economic consequences and repercussions was highlighted in the analysed case study.
EN
El Jadida Beach (X: -8.5007116; Y: 33.2316326) is a sandy beach of low altitude that constitutes a kind of enclave located between the port of El Jadida and rocky outcrops. It is influenced by natural and anthropic factors, as well as the impact of tourism, particularly during the summer, when sand is used for amusement activities (Beach Ball competition). In order to follow the morphodynamic changes of this beach, we carried out a study on two different time scales: a fifty-five years (1963 – 2018) shoreline evolution study using aerial photos and satellite images based on GIS tools using the Digital Shoreline Analysis System (DSAS) and a two-years (2017–2019) morphological beach study using a Differential Global Positioning System (DGPS). According to the results obtained by the diachronic study, the beach studied showed erosion in its middle and an accumulation at these bulges. This result is due to the presence of the harbor breakwater to the NW and the rocky outcrops to the SE; acting as a barrier preventing the movement of sediments and the erosion in the middle can be explained by the reduction of the sediment supply from the Oued Oum Erabia and by the exposure of this part to the dominant swells and also the human activities like used the beach for amusement activities (Beach Ball competition and other). Beach profile observations results show accumulation in the subaerial beach and erosion in the lower part of the foreshore. The study on two different time scales adopted in this paper, allowed us to understand longshore and cross-shore sedimentary mobility.
EN
Shoreline changes have become a serious problem in all coastal areas worldwide. This study aimed to detect shoreline changes and analyze the shoreline change rate caused by abrasion and accretion in the coastal area of Supiori Regency, Indonesia. Landsat 8/9 imagery was used to determine the position of the coastline in 2013 and 2023. The shoreline movement (Net Shoreline Movement) and the shoreline change rate (End Point Rate) were analyzed using the Digital Shoreline Analysis System installed on ArcMap software. The results of this study indicate that there has been abrasion and accretion where there are several very significant locations. The maximum distance of the shoreline movements due to abrasion and accretion occurred in the Supiori Selatan District as far as -67.15 and 92.86 m, respectively. The average shoreline movement caused by abrasion ranges from -11.37 to -13.59 m and from 9.75 to 15.64 m in the case of accretion. From the comparison of abrasion and accretion, only the Kepulauan Aruri District has a positive value (dominant accretion), while the other four districts have a negative value (dominant abrasion). The shoreline changes rates in the study area caused by abrasion and accretion ranged from -1.22 to -1.46 m/yr and 1.05 to 1.68 m/yr, respectively. Abrasion and accretion in the study area are predominantly caused by natural factors such as waves, currents, and river flows, as well as caused by non-natural factors mainly due to human activities. Information on shoreline changes in the study area is an important aid for stakeholders involved in coastal area management. Therefore, planning, strategies, and mitigation efforts are urgently needed to anticipate increased coastal erosion and possible negative impacts.
EN
Shoreline changes are crucial for assessing human-ecosystem interactions in coastal environments. They are a valuable tool for determining the environmental costs of socioeconomic growth along coasts. In this research, we present an assessment of shoreline changes along the eastern coast of Lahou-Kpanda of the Ivory Coast during the period from 1980 to 2020 by applying Digital Shoreline Analysis System method using Landsat Data Series. The measurement of the shoreline dynamics of the Lahou-Kpanda coastline is mainly described in three parts: the west straight cordon, the dynamics at the mouth and the east straight cordon. The findings show a drastic reduction in natural shorelines. The greatest transition occurred along the mouth segment of the coast, where the average erosive velocity approaches 90 meters each year and the average distance has decreased by around 2 kilometers. The Ivory Coast lost more than 40% of its biological shorelines between 1980 and 2020, according to this report, a worrying development because these are regions that were once biologically abundant and highly rich. In general, human operations on the Ivory Coast’s shorelines have never had such an impact. The effects of these changes on habitats, as well as the vulnerability of new shoreline investments to increased human activity and sea-level rise, must be measured.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.