scholarly journals Analysis of Shoreline Change along Cape Coast-Sekondi Coast, Ghana

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Ishmael Yaw Dadson ◽  
Alex Barimah Owusu ◽  
Osman Adams
Keyword(s):  
Satellite Image ◽  
Shoreline Change ◽  
Aerial Photographs ◽  
Cape Coast ◽  
Change Analysis ◽  
Community Interactions ◽  
Erosion And Accretion ◽  
End Point Rate

The two most important factors constantly impinging on the net movement of shorelines are erosion and accretion. This study analyzed the role of erosion and accretion in shoreline changes along the coast between Cape Coast and Sekondi in the central and western regions of Ghana, respectively. Aerial photographs, satellite images, and topographical maps were used. In addition, field survey using Global Positioning System (GPS) was conducted at selected locations due to the unavailability of satellite image for 2013. Shoreline change analysis was conducted using Digital Shoreline Analysis Systems based on End Point Rate formula. In addition, community interactions were also conducted to get first-hand information from the local inhabitants. The study finds that the shoreline under study has been fluctuating. The sea advanced inland between 1972 and 2005, which is attributed mainly to intense erosion. The study further reveals that, in the past five years, the shoreline had been retreating mainly due to increased accretion. It is recommended that the shoreline under study should be monitored regularly to keep abreast with net movements that will occur in either the short term or the long term so as to factor the net effect into the management of the coastal zone.

scholarly journals Storm Driven Migration of the Napatree Barrier, Rhode Island, USA

Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 330
Author(s):  
Bryan A. Oakley
Keyword(s):  
Rhode Island ◽  
Shoreline Change ◽  
Aerial Photographs ◽  
Tropical Storms ◽  
Lower Intensity ◽  
Storm Activity ◽  
The Impact ◽  
Washover Fan

Napatree Point, an isolated barrier in southern Rhode Island, provides a case study of barrier spit migration via storm driven overwash and washover fan migration. Documented shoreline changes using historical surveys and vertical aerial photographs show that the barrier had little in the way of net change in position between 1883 and 1939, including the impact of the 1938 hurricane. The barrier retreated rapidly between 1945 and 1975, driven by both tropical and extra-tropical storms. The shoreline position has been largely static since 1975. The removal of the foredune during the 1938 hurricane facilitated landward shoreline migration in subsequent lower intensity storms. Dune recovery following the 1962 Ash Wednesday storm has been allowed due to limited overwash and barrier migration over the last several decades. Shoreline change rates during the period from 1945–1975 were more than double the rate of shoreline change between 1939 and 2014 and triple the rate between 1883 and 2014, exceeding the positional uncertainty of these shoreline pairs. The long-term shoreline change rates used to calculate coastal setbacks in Rhode Island likely underestimate the potential for rapid shoreline retreat over shorter time periods, particularly in a cluster of storm activity. While sea-level rise has increased since 1975, the barrier has not migrated, highlighting the importance of storms in barrier migration.

scholarly journals Rapid retreat of permafrost coastline observed with aerial drone photogrammetry

2019 ◽  
Vol 13 (5) ◽  
pp. 1513-1528 ◽  
Author(s):  
Andrew M. Cunliffe ◽  
George Tanski ◽  
Boris Radosavljevic ◽  
William F. Palmer ◽  
Torsten Sachs ◽  
...  
Keyword(s):  
Coastal Erosion ◽  
Average Rate ◽  
Temporal Frequency ◽  
Shoreline Change ◽  
Yukon Territory ◽  
Aerial Photographs ◽  
The Arctic ◽  
Storm Events ◽  
Short Term

Abstract. Permafrost landscapes are changing around the Arctic in response to climate warming, with coastal erosion being one of the most prominent and hazardous features. Using drone platforms, satellite images, and historic aerial photographs, we observed the rapid retreat of a permafrost coastline on Qikiqtaruk – Herschel Island, Yukon Territory, in the Canadian Beaufort Sea. This coastline is adjacent to a gravel spit accommodating several culturally significant sites and is the logistical base for the Qikiqtaruk – Herschel Island Territorial Park operations. In this study we sought to (i) assess short-term coastal erosion dynamics over fine temporal resolution, (ii) evaluate short-term shoreline change in the context of long-term observations, and (iii) demonstrate the potential of low-cost lightweight unmanned aerial vehicles (“drones”) to inform coastline studies and management decisions. We resurveyed a 500 m permafrost coastal reach at high temporal frequency (seven surveys over 40 d in 2017). Intra-seasonal shoreline changes were related to meteorological and oceanographic variables to understand controls on intra-seasonal erosion patterns. To put our short-term observations into historical context, we combined our analysis of shoreline positions in 2016 and 2017 with historical observations from 1952, 1970, 2000, and 2011. In just the summer of 2017, we observed coastal retreat of 14.5 m, more than 6 times faster than the long-term average rate of 2.2±0.1 m a−1 (1952–2017). Coastline retreat rates exceeded 1.0±0.1 m d−1 over a single 4 d period. Over 40 d, we estimated removal of ca. 0.96 m3 m−1 d−1. These findings highlight the episodic nature of shoreline change and the important role of storm events, which are poorly understood along permafrost coastlines. We found drone surveys combined with image-based modelling yield fine spatial resolution and accurately geolocated observations that are highly suitable to observe intra-seasonal erosion dynamics in rapidly changing Arctic landscapes.

scholarly journals FIELD INVESTIGATION OF SEDIMENT TRANSPORT PATTERN IN A CLOSED SYSTEM

1976 ◽  
Vol 1 (15) ◽  
pp. 72
Author(s):  
Tsuguo Sunamura ◽  
Kiyoshi Horikawa
Keyword(s):  
Sediment Transport ◽  
Closed System ◽  
Shoreline Change ◽  
Field Investigation ◽  
Depositional Environments ◽  
Aerial Photographs ◽  
Beach Sand ◽  
Sieve Analysis ◽  
Alongshore Sediment Transport

In order to elucidate the transport pattern of sediment in a closed system, a pocket beach was chosen and investigated from various aspects. This investigation included the following studies: (1) bathymetric survey by an echo sounder, (2) survey of submarine geology using an acoustic probe, (3) observation of nearshore current systems using floats, (4) documentation of the transport pattern of suspended sediment by aerial photographs, (5) examination of depositional environments of bottom and beach material by sieve analysis, (6) inference of long-term alongshore sediment transport pattern from the grain size properties of beach sand, and measurement of short-term trends by use of fluorescent sand, and (7) examination of long-term shoreline change using old and recent maps.

Contemporary challenges for Shoreline Change Analysis

2020 ◽  
Author(s):  
Sue Brooks ◽  
Jamie Pollard ◽  
Tom Spencer
Keyword(s):  
Water Level ◽  
Methodological Approach ◽  
Shoreline Change ◽  
Data Availability ◽  
Aerial Photographs ◽  
Publication Date ◽  
Landsat Images ◽  
Change Analysis ◽  
Decadal Scale ◽  
Shoreline Change Analysis

<p>Shoreline change analysis has been deployed across a range of spatio-temporal scales. Accordingly, shoreline change studies have sought to capture shoreline dynamics at a variety of scales, ranging from the local impacts of individual storms to global trends measured over multiple decades. The scale at which we can approach the issue of shoreline change is, to a large extent, determined by the availability of data over time and space. With existing threats from the interactions between accelerated sea level rise, changing storminess and human intervention, shoreline change analysis has never been more relevant or challenging. Historic, centennial-scale shoreline change analysis relies on historic maps where there is normally just a single proxy indicator for consistent shoreline position; the mean water level of ordinary tides on UK Ordnance Survey maps, for example. Occasionally where there are specific coastal landforms that can be mapped, there might be a second proxy such as cliff top position. Shoreline change rates can be determined by extracting these proxies from sequential map surveys, provided the survey dates (ie: not the map publication date) are known.</p><p> </p><p>Shoreline change quantification for more recent decadal-scale periods has been greatly enhanced by increased data availability. This is exemplified by analyses that use widespread coverage available from aerial photographs (past 3 decades). Even more recently on near-annual scales Light Detection and Ranging (LiDAR) data are becoming the norm for capturing storm impacts and shoreline change, enabling volumetric assessments of change in addition to the more traditional linear approaches. LiDAR is enhanced by ground survey Real Time Kinematic (RTK) Instrumentation that can be timed to coincide with storms. As the frequency of dataset capture has increased so has the spatial scale of coverage. Hence the latest shoreline change assessments are global in scale and use Landsat images to focus on hotspots of shoreline change (advance as well as retreat) over the past 30 years. Considering all scales together raises three central questions for shoreline change analysis and these are addressed in this paper.</p><p> </p><p>Firstly, what methodological approach is most suitable for delimiting shorelines and generating the underpinning digitised shorelines for shoreline change assessment?</p><p>Secondly, what lessons can be learnt from using an approach that combines both proxy-based (visually discernible signatures) and datum-based (related to a particular water level) shorelines that change differentially with respect to different process-drivers?</p><p>Thirdly, given the current state-of-the-art around data availability, what is the most appropriate scale to approach shoreline change assessments?</p>

scholarly journals DETECCIÓN DE CAMBIOS DE LA LÍNEA COSTERA AL NORTE DEL DISTRITO DE BUENAVENTURA MEDIANTE EL USO DE SENSORES REMOTOS

2017 ◽  
Vol 46 (1) ◽  
Author(s):  
María Alejandra Cifuentes Ossa ◽  
Leidy Viviana Rosero Henao ◽  
John Josephraj Selvaraj
Keyword(s):  
Salt Marshes ◽  
Shoreline Change ◽  
The United States ◽  
Shoreline Changes ◽  
Natural Processes ◽  
Northern District ◽  
Erosion And Accretion ◽  
Analysis System ◽  
End Point Rate ◽  
Colombian Pacific

This study focuses on detecting the magnitude of shoreline changes of the northern District ofBuenaventura, in the Colombian Pacific, over a 30-year period, on a coast where the geomorphologyincludes beaches, cliffs, estuaries, deltas and salt marshes. Satellite imagery (Landsat MSS, ETM + andOLI TIRS) were used to detect historical positions of the shoreline in order to identify the processes ofchange, in terms of erosion and accretion, from 1986 to 2015. Statistical analysis of changes was carriedout to estimate distances and shoreline change rates, using a tool developed by the United States GeologicalSurvey (USGS): Digital Shoreline Analysis System (DSAS). The statistics on Net Shoreline Movement(NSM) and End Point Rate (EPR), provided information about the magnitude and trends of changes in theshoreline. The results indicate that areas with more advanced processes of accretion correspond to sectorsin Boca San Juan, Puerto España and near to La Concepción beach in the Department of Valle del Caucaand in the south of Chavica, in the Department of Chocó; all these sectors are located in the northern partof the study area. Also in the same sectors, particularly around Chavica, the most advanced processes oferosion were found, along with El Choncho beach and a small sector in the Malaga bay. Some sectors ofthe shoreline remained mostly stable, such as Malaga and Buenaventura Bays. Average shoreline changerate of (-) 0.21m per year was found, reflecting its erosive tendency with maximum EPR values 26.92mof accretion and (-) 21.01m for coastal erosion. Natural processes such as the influence of river dischargeand El Niño phenomenon, have contributed to these shoreline changes. The identified erosion and accretionprocesses can be recognized as priority areas of coastal management in the Colombian Pacific.

Shoreline Change Analysis in Parts of the Barrier–Lagoon and Mud Sections of Nigeria Coast

2017 ◽  
Vol 04 (04) ◽  
pp. 1850004 ◽  
Author(s):  
G. Badru ◽  
S. Odunuga ◽  
A. Omojola ◽  
E. Oladipo
Keyword(s):  
Extreme Event ◽  
Average Rate ◽  
Storm Surges ◽  
Shoreline Change ◽  
Extraction Methods ◽  
Change Analysis ◽  
Adaptation Measures ◽  
End Point Rate ◽  
Landsat Satellite ◽  
Shoreline Change Analysis

This study assesses the short- and long-term changing position of the shorelines along the barrier lagoon and mud section of the Nigeria coast using remote sensing techniques. Five shoreline positions, covering a 30-year period (1986–2016), were extracted from medium resolution multi-spectral Landsat satellite imageries using both manual and semi-automatic shoreline extraction methods. Approximately, 533 orthogonal transects were cast using DSAS at simple right angles along the entire coast at 250-m interval. The shoreline change analysis was calculated using the Net Shoreline Movement and the End Point Rate techniques. The results show that the shoreline is highly dynamic; with the average rate of erosion estimated to be 28.08[Formula: see text]m/year and the average rate of accretion estimated to be 20.56[Formula: see text]m/year. While the persistence of erosional tendencies was found mainly in the Okesiri-Abereke-Aiyetoro parts of the mud section of the shoreline, the accretional tendencies was found mainly in the Aboraji-Araromi (barrier lagoon) and the Ajegunle-Jinriwo-Awoye (mud section) parts of the shoreline. The high dynamism of the shoreline is mainly attributed to the increasing frequency of storm surges in the area with over 13 incidents experienced within this period. This study submits that addressing coastal erosion and flooding problems in Nigeria should be based on the system boundary model where the coastal process and dynamics are constantly monitored holistically rather than locally or regionally as it is currently being done. This will also ensure the incorporation of the extent, frequency and intensity of extreme event in the development of adaptation measures.

scholarly journals Perubahan Garis Pantai di Pesisir Cirebon Berdasarkan Analisis Spasial

2018 ◽  
Vol 2017 (2) ◽  
Author(s):  
Aida Heriati ◽  
Semeidi Husrin
Keyword(s):  
Coastal Area ◽  
Fundamental Problem ◽  
Shoreline Change ◽  
Coastal Communities ◽  
Severe Damage ◽  
Change Analysis ◽  
Coastal Morphology ◽  
Erosion Processes ◽  
Coastal Area Management

ABSTRAKInformasi kerusakan daerah Pesisir Utara Jawa bukan hal yang baru. Daerah pesisir Cirebon sebagai salah satu bagian Pesisir Utara Jawa mengalami permasalahan dinamika pesisir yang ditandai oleh erosi dan sedimentasi pantai. Erosi dan sedimentasi merupakan permasalahan mendasar dalam pengelolaan wilayah pesisir. Penelitian ini mengkaji kerusakan pesisir Cirebon ditinjau melalui perubahan garis pantai yang ditimbulkan oleh proses sedimentasi dan erosi yang terjadi secara alami ataupun akibat aktivitas manusia. Pengolahan data satelit Landsat tahun 1999 dan 2013 memberikan informasi sedimentasi dan erosi di sekitar pesisir Cirebon. Hasil perubahan garis pantai dari analisis satelit diverifikasi dengan pengamatan di lapangan dan wawancara dengan masyarakat pesisir yang dilakukan pada Juni 2013. Analisis memperlihatkan perubahan garis pantai di Pesisir Cirebon sangat dipengaruhi oleh aspek-aspek hidro-oseanografi, morfologi pantai, dan aktivitas manusia. Hasil ini diharapkan dapat menambah informasi mengenai kondisi pesisir di Cirebon yang dapat digunakan dasar dalam pengelolaan kerusakan wilayah pesisir sesuai dengan kondisi real di lapangan.Kata kunci: Cirebon, garis pantai, erosi, akresi, panturaABSTRACTThe damage of coastal area in Northen Java has been known for decades. As part of Northen Java Coastal, Cirebon coastal area suffered from severe damage due to erosion-abrasion phenomenon and turned to be a fundamental problem in coastal area management. This research analyses Cirebon coastal changes by analising shoreline changes induced by long term sedimentation and erosion processes. Landsat data in 1999 and 2013 are used in shoreline change analysis. The sattelite analysis results are verified by field observations and coastal communities interview in June 2013. The results show that the coastline dynamics of Cirebon are strongly influenced by hydro-oceanography aspects, coastal morphology and human activities. This result provides valuable information on the latest conditions of coastal area in Cirebon and this can be used as basis for land use management and future mitigation of costal areas.Keywords: Cirebon, coastlines, erosion, accretion, pantura

scholarly journals BEACH MORPHOLOGICAL CHANGES ON SENDAI COAST BY TYPHOON LIONROCK

2018 ◽  
pp. 34
Author(s):  
Yuta Mitobe ◽  
Hitoshi Tanaka ◽  
Akihiro Suzuki ◽  
Makoto Umeda ◽  
Daisuke Komori ◽  
...  
Keyword(s):  
Pacific Coast ◽  
Morphological Changes ◽  
Shoreline Change ◽  
Aerial Photographs ◽  
Change Analysis ◽  
Field Surveys ◽  
Beach Processes ◽  
The Pacific ◽  
History Of ◽  
The Impact

In 2016, a few typhoons attacked Tohoku Area of Japan, and one of them, named Typhoon Lionrock, approached and hit Tohoku Area from the Pacific Coast, which is the first observed typhoon to have such a course in the observation history of Japan. In order to know magnitude of the storm surge and high waves induced by the typhoon and their influence on the coastal area, field surveys were conducted on the day of the typhoon arrival and also the next day. The target of the survey was Sendai Coast, which is a part of the Pacific Coast of Tohoku Area. The coast was severely affected by the 2011 Great East Japan Earthquake Tsunami, and its effect on the beach morphology still remains according to shoreline change analysis with aerial photographs by Hoang et al. (2016). In this paper, the shoreline changes by and after the typhoon were analyzed with the aerial photographs taken in every one or two months to understand its effect on the beach processes. And the results were combined with the shoreline data after the 2011 tsunami to see the impact of the typhoon on the beach processes under the recovery from the tsunami event.

scholarly journals LONG-TERM MORPHOLOGICAL EVOLUTION MODEL

2018 ◽  
pp. 64
Author(s):  
Bradley Johnson ◽  
Jesse McNinch
Keyword(s):  
South Carolina ◽  
Morphological Evolution ◽  
Shoreline Change ◽  
One Dimensional ◽  
The Past ◽  
Longshore Transport ◽  
Model Predictions ◽  
Erosion And Accretion ◽  
The One

Nearshore morphology models predicting storm-scale erosion have been in use for the past several decades. These empirical tools typically focus on a single time-scale, which limits the utilization. For example, models developed to predict cross-shore storm erosion are poorly suited for longer-term simulations that include the beach recovery between events and gradients in longshore transport. Herein, the one-dimensional model CSHORE is extended to include shoreline change associated with along- shore variation in transport. A comparison of model predictions with long-term shoreline data from South Carolina demonstrate reasonable agreement with both erosion and accretion.

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