Long-Term Shoreline Evolution Using DSAS Technique: A Case Study of Quang Nam Province, Vietnam

A Quang Nam coastline, located in the central of Vietnam, has been strongly affected by severe erosion and accretion due to climate change and human activities. Thus, understanding the causes and mechanisms of coastal morphology changes is essential to offer optimal coastal management and protection solutions. In this research, the Digital Shoreline Analysis System (DSAS) technique developed by the United States Geological Survey was adopted to calculate rate-of-change statistics from multiple historical coastline positions of Quang Nam province extracted from satellite images, i.e., Landsat and Sentinel images from 1990 to 2019. The coastal dynamic was digitized, visualized, and compared by two statistical parameters provided in DSAS, namely End Point Rate (EPR) and Linear Regression Rate (LRR). The final results reveal that the Quang Nam coast experienced remarkable phenomena of erosion and accumulation over the past three decades. The total number of erosional and accretional transects obtained from the EPR results are 401 and 414, with annual change rates of −1.7 and 0.77 m/year, respectively. The LRR parameter was also considered and illustrated a significant correlation with the EPR, as the obtained R2 value of 0.96. The lowest value of EPR over the period 1990–2019 is −42.4 m/year, highlighting the most significant erosion at the north of Cua Dai estuary, whereas coastline advance is recorded in the south segment. As a result, this study’s outcomes provide helpful information for better and sustainable coastal management in Quang Nam province of Vietnam.

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Future Decreases in Freezing Days across North America

Journal of Climate ◽

10.1175/jcli-d-15-0802.1 ◽

2016 ◽

Vol 29 (19) ◽

pp. 6923-6935 ◽

Cited By ~ 5

Author(s):

Michael A. Rawlins ◽

Raymond S. Bradley ◽

Henry F. Diaz ◽

John S. Kimball ◽

David A. Robinson

Keyword(s):

North America ◽

Climate Models ◽

Regional Climate ◽

Regional Climate Models ◽

The United States ◽

Rate Of Change ◽

Mean Annual Temperature ◽

The North ◽

Air Temperatures ◽

Climate Change Assessment

Abstract This study used air temperatures from a suite of regional climate models participating in the North American Climate Change Assessment Program (NARCCAP) together with two atmospheric reanalysis datasets to investigate changes in freezing days (defined as days with daily average temperature below freezing) likely to occur between 30-yr baseline (1971–2000) and midcentury (2041–70) periods across most of North America. Changes in NARCCAP ensemble mean winter temperature show a strong gradient with latitude, with warming of over 4°C near Hudson Bay. The decline in freezing days ranges from less than 10 days across north-central Canada to nearly 90 days in the warmest areas of the continent that currently undergo seasonally freezing conditions. The area experiencing freezing days contracts by 0.9–1.0 × 106 km2 (5.7%–6.4% of the total area). Areas with mean annual temperature between 2° and 6°C and a relatively low rate of change in climatological daily temperatures (<0.2°C day−) near the time of spring thaw will encounter the greatest decreases in freezing days. Advances in the timing of spring thaw will exceed the delay in fall freeze across much of the United States, with the reverse pattern likely over most of Canada.

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

Bulletin of Marine and Coastal Research ◽

10.25268/bimc.invemar.2017.46.1.719 ◽

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.

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Which are the highest peaks in the US Arctic? Fodar settles the debate

The Cryosphere ◽

10.5194/tc-10-1245-2016 ◽

2016 ◽

Vol 10 (3) ◽

pp. 1245-1257 ◽

Cited By ~ 5

Author(s):

Matt Nolan ◽

Kit DesLauriers

Keyword(s):

The United States ◽

Disruptive Innovation ◽

Airborne Lidar ◽

United States Geological Survey ◽

Climate Trends ◽

Gps Measurements ◽

The North ◽

Recent Climate ◽

The Us ◽

North American Arctic

Abstract. Though an outstanding achievement for their time, the United States Geological Survey (USGS) topographic maps of the eastern Alaskan Arctic nonetheless contain significant errors, and in this paper we address one of them. Specifically, USGS maps of different scale made in the late 1950s alternate between Mt. Chamberlin and Mt. Isto as the tallest peak in the US Arctic. Given that many of the peaks here are close in height and covered with glaciers, recent climate change may also have changed their height and their order. We resolved these questions using fodar, a new airborne photogrammetric technique that utilizes structure-from-motion (SfM) software and requires no ground control, and validated it using GPS measurements on the peaks as well as airborne lidar. Here we show that Mt. Chamberlin is currently the third tallest peak and that the order and elevations of the five tallest mountains in the US Arctic are Mt. Isto (2735.6 m), Mt. Hubley (2717.6 m), Mt. Chamberlin (2712.3 m), Mt. Michelson (2698.1 m), and an unnamed peak (2694.9 m); these heights are relative to the NAVD88 GEOID12A vertical datum. We find that it is indeed plausible that this ranking has changed over time and may continue to change as summit glaciers continue to shrink, though Mt. Isto will remain the highest under current climate trends. Mt. Isto is also over 100 m taller than the highest peak in Arctic Canada, making it the highest peak in the North American Arctic. Fodar elevations compared to within a few centimeters of our ground-based GPS measurements of the peaks made a few days later and our complete validation assessment indicates a measurement uncertainty of better than &pm;20 cm (95 % RMSE). By analyzing time series of fodar maps, we were able to detect topographic change on the centimeter level on these steep slopes, indicating that fodar can be used to measure mountain snow packs for water resource availability or avalanche danger, glacier volume change, and slope subsidence, as well as many other applications of benefit to society. Compared to lidar, the current state-of-the-art airborne topographic mapping, we found this SfM technique as accurate, more useful scientifically, and significantly less expensive, suggesting that fodar is a disruptive innovation that will enjoy widespread usage in the future.

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Shoreline changes along the Kutubdia Island, south east Bangladesh using digital shoreline analysis system

Bangladesh Journal of Scientific Research ◽

10.3329/bjsr.v27i1.26228 ◽

2016 ◽

Vol 27 (1) ◽

pp. 99-108 ◽

Cited By ~ 5

Author(s):

Md Ashraful Islam ◽

Md Shakhawat Hossain ◽

Tanzeer Hasan ◽

Sanzida Murshed

Keyword(s):

Linear Regression ◽

Shoreline Changes ◽

Change Dynamics ◽

Weighted Linear Regression ◽

The North ◽

Medium Resolution ◽

Digital Shoreline Analysis System ◽

Analysis System ◽

End Point Rate

A ~65 km coastal stretch has been analyzed to estimate the change dynamics of Kutubdia Island with the help of digital shoreline analysis system (DSAS). This study investigated the reliability of medium resolution satellite imagery for mapping shoreline positions and for estimating historic rates of changes. Nine shoreline positions were extracted on 1972, 1976, 1980, 1989, 1999, 2004, 2009, 2011 and 2014 covering a long term of 42 years period. Rates of shoreline changes were estimated by four statistical methods namely, end point rate (EPR), linear regression rate (LRR), weighted linear regression (WLR) and least median of squares (LMS) by using DSAS and subsequently all the methods were verified with the correlation coefficient (R).The scrutiny of shoreline changes shows that the erosion during the last 42 years has affected the island, with some exception, at the north and west segment where minor accretion has been documented. The average rates of changes estimated for north, south, east and west segment using WLR, LMS, EPR and LRR are Ñ4.0 m/yr, Ñ33.7 m/yr Ñ2.6 m/yr and Ñ5.6 m/yr, respectively. The outcome of this particular analysis might be useful for proper planning and management of Kutubida Island. However, this may also be used in statistical modeling for forecasting the future shoreline position.Bangladesh J. Sci. Res. 27(1): 99-108, June-2014

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A Shoreline Change Detection (2012-2021) and forecasting Using Digital Shoreline Analysis System (DSAS) Tool: A Case Study of Dahej Coast, Gulf of Khambhat, Gujarat, India

Indonesian Journal of Geography ◽

10.22146/ijg.56297 ◽

2021 ◽

Vol 53 (2) ◽

Author(s):

Mousumi Dey ◽

Shanmuga Priyaa S ◽

B. K. Jena

Keyword(s):

Linear Regression ◽

Change Detection ◽

Seasonal Pattern ◽

Shoreline Change ◽

Rate Of Change ◽

Shoreline Position ◽

Regression Rate ◽

Filter Model ◽

Analysis System ◽

End Point Rate

Shoreline is one of the coastal landforms which continuously changing in nature. Hence, monitoring of shoreline change is very obligate to understand and manage the coastal process. The objectives of the present study were i) to identify the shoreline change detection (2012 to 2021) based on various statistical methods along Dahej coast, Gujrat. ii) to forecast the shoreline position after 10 years. DSAS tool and Multi-dated satellite images (Sentinel-2 and LISS-IV) were used in present study. The result shows that, the pattern of rate of change was more or less similar with little variation in the values for the 3 different methods. Highest erosion rate was for End Point Rate, Linear Regression Rate and Weighted Linear Regression rate found -33m, -31m, -31m respectively at transect no 54. Highest accretion rate was 38m (EPR), 50m (LRR), 51m (WLR) along a particular transect. The forecast of shoreline position for the year 2032 observed through Kalman Filter Model. Seasonal analysis for 3 years (2016, 2017, 2018) shows the region not having any seasonal pattern.

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The observation of birds as informative tools to develop citizen science: Contributions of a 10-year record in the state of Chihuahua, Mexico

10.1101/704676 ◽

2019 ◽

Author(s):

Fidel González-Quiñones ◽

Luis Roberto Granados ◽

José Manuel Jurado Ruiz ◽

Javier Tarango ◽

Juan D. Machin-Mastromatteo ◽

...

Keyword(s):

Decision Making ◽

Citizen Science ◽

Professional Education ◽

Environmental Issues ◽

The United States ◽

Research Centre ◽

Service Research ◽

United States Geological Survey ◽

The North ◽

Urban Characteristics

AbstractThis article analyses historical data from observations made to birds in breeding, throughout two routes with urban characteristics and during a consecutive period of 10 years (2009-2018), following a precise methodology designed by the North American Breeding Bird Survey. The analyzed routes are officially registered in the Mexican Commission for Biodiversity’s Knowledge and Use, the United States Geological Survey Patuxent Wildlife Research Center, and the Canadian Wildlife Service Research Centre. The observations were made by citizens without formal professional education; hence the results may be considered within the framework of citizen science. Their contributions provided important data for decision-making regarding environmental issues, since the presence of birds is considered one of the main indicators on health conditions of an ecosystem. Data analysis identified two basic conditions: (i) a reduction of the 23% in the number of species found, as many of them disappeared during counting; and (ii) the significant increase in population of other species, three of pigeons among them. Apart from the study of bird behavior in the routes with urban characteristics, the article acknowledges the lack of connection and use of the information produced from monitoring for decision-making and education regarding environmental issues. Therefore, we consider crucial to create scientific observatories, both available to experts in the field and to the general population, as the ultimate purpose would be the production of citizen science.

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The Lower Palaeozoic shale gas play in Denmark

Geological Survey of Denmark and Greenland Bulletin ◽

10.34194/geusb.v31.4640 ◽

1969 ◽

Vol 31 ◽

pp. 19-22 ◽

Cited By ~ 3

Author(s):

Niels H. Schovsbo ◽

Arne T. Nielsen ◽

Donald L. Gautier

Keyword(s):

North Sea ◽

Best Practice ◽

The United States ◽

United States Geological Survey ◽

The North ◽

Alum Shale ◽

Wide Range ◽

The North Sea ◽

Potential Resource ◽

Lower Palaeozoic

The unconventional gas resources in the Lower Palaeozoic shale of Denmark were recently assessed by the United States Geological Survey (USGS; Gautier et al. 2013). Assuming unrestricted application of best practice current technology, recoverable gas resources of 0 to 130 × 109 Nm3 gas were estimated onshore (mean = 67 × 109 Nm3 gas) and 0 to 228 × 109 Nm3 gas were estimated offshore (mean = 119 × 109 Nm3 gas), i.e. a total estimated mean of 186 × 109 Nm3 gas (Nm3: normal cubic metre, unit used for natural gas at 0°C and 101.325 kPa). Nearly all of this potential resource is assumed to be contained in the Cambro-Ordovician Alum Shale. The wide range of estimates reflects the sparse data and the geological uncertainty inherent in the still untested play. The estimated mean quantity of gas resource is comparable to the total volume of gas produced from the Danish part of the North Sea during 1972–2011 and twice the amount of the estimated remaining reserves of conventional gas in the Danish part of the North Sea.

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The Application of GIS and Remote Sensing in a Spatiotemporal Analysis of Coastline Retreat in Rufisque, Senegal

Geomatics and Environmental Engineering ◽

10.7494/geom.2021.15.3.55 ◽

2021 ◽

Vol 15 (3) ◽

pp. 55-80

Author(s):

Cheikh Tidiane Koulibaly ◽

Johnson O. Ayoade

Keyword(s):

Coastal Erosion ◽

Shoreline Change ◽

Spatiotemporal Analysis ◽

The United States ◽

United States Geological Survey ◽

Landsat Images ◽

Change Analysis ◽

Gis And Remote Sensing ◽

Local Residents ◽

Analysis System

This paper is aimed at analyzing the phenomenon of shoreline retreat in the locality of Rufisque from 1978 to 2018 mainly using geospatial data and field visits. A set of Landsat images from different dates at 10 year intervals was then acquired through the United States Geological Survey platform and shoreline change analysis was run using the Digital Shoreline Analysis System. In addition to that desktop work, interactions with local residents allowed the determination of ongoing adaptation strategies actually in place to cope with coastal erosion. The study showed that Rufisque is subject to serious rates of erosion reaching −19.48 m/year from 1978–1988, close to −8 m/year from 1988–1998, −5.88 m/year from 1998–2008 and −6.67 m/year from 2008–2018. Beside that coastal erosion, it has been noticed that the coastline also experienced in some of its parts cases of accretion reaching 4.94 m/year for 1988–1998, 7.29 m/year from 1998–2008 and 7.68 m/year during the period 2008–2018. In terms of surfaces, Rufisque’ shoreline respectively lost 156.81 ha (1978–1988), 80.55 ha (1988–1998), 6.94 ha (1998–2008), 12.93 ha (2008–2018) and in the same note gained 2.86 ha (1988–1998), 32.51 ha (1998–2008) and 19.16 ha (2008–2018) attesting to the fact that the coastline is subject to both spatiotemporal changes. Finally, this study also reveals that while authorities’ reaction is taking place at much lower pace, local communities are actually using their ingenuity to put in place strategies to tackle coastal erosion.

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A DSAS-based study of central shoreline change in Jiangsu over 45 years

Anthropocene Coasts ◽

10.1139/anc-2020-0001 ◽

2021 ◽

Vol 4 (1) ◽

pp. 115-128

Author(s):

Yuan Song ◽

Yongming Shen ◽

Ruofan Xie ◽

Jialin Li

Keyword(s):

Cross Section ◽

Large Scale ◽

Shoreline Change ◽

Sand Ridge ◽

Change Rate ◽

Shoreline Evolution ◽

Quantitative Monitoring ◽

Length Changes ◽

Analysis System ◽

End Point Rate

A large-scale sand ridge group is distributed in the central Jiangsu coastal area, and a deposition muddy sea bank was developed in the nearshore area. Quantitative monitoring of coastline changes is of great significance for tidal beach development and protection. The shorelines of the central coast of Jiangsu within six periods (1973–2018) were extracted in this study, and their length changes over the years were analyzed. The Digital Shoreline Analysis System (DSAS) was employed to generate a cross section perpendicular to the baseline and calculate the linear regression rate (LRR) of the shoreline, changes in end point rate (EPR), and net shoreline movement (NSM), based on which the shoreline change features were analyzed. The DSAS results indicated that the shorelines in the study area maintained fluctuating growth and presented a continuous advancing trend towards the sea. From the changes in shoreline evolution distance during 1973–2018, the advancing shorelines in the study area accounted for over 50% of the total shorelines and presented first rising and then declining trends with the period of 2003–2013 taken as the time boundary. The average shoreline change rate was 207 m/year, and the periods with the highest change degrees were 1983–1993 and 1993–2013. The shoreline change tended to be stable during 2013–2018, and only a few estuaries and ports underwent obvious erosion and sedimentation.

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Dinamika perubahan garis pantai Kabupaten Kendal tahun 2000-2020

Majalah Geografi Indonesia ◽

10.22146/mgi.62301 ◽

2021 ◽

Vol 35 (1) ◽

pp. 75

Author(s):

Bernadetta Indri Dwi Astuti ◽

Agung Laksono ◽

Dzakwan Taufiq Nur Muhammad ◽

Intan Fatin Nurbaiti ◽

Noverita Nur Hanifah ◽

...

Keyword(s):

Linear Regression ◽

Shoreline Change ◽

Rate Of Change ◽

Regression Rate ◽

End Point ◽

Digital Shoreline Analysis System ◽

Landsat 7 ◽

Analysis System ◽

End Point Rate ◽

The Impact

Abstrak Pemantauan garis pantai akibat adanya proses akresi dan abrasi merupakan salah satu upaya untuk menjaga batas wilayah wilayah di Kabupaten Kendal. Lima multitemporal citra Landsat 7 ETM+ dalam periode tahun 20 tahun (2000-2020) digunakan untuk menganalisis perubahan garis pantai di Kabupaten Kendal.Tujuan dari penelitian ini adalah untuk menganalisis perubahan garis pantai dan menganalisis dampak serta upaya mitigasi dalam menangani perubahan garis pantai di Kabupaten Kendal. Digital Shoreline Analysis System (DSAS) digunakan untuk menganalisis perubahan garis pantai dengan metode Net Shoreline Movement (NSM), End Point Rate (EPR), dan Linear Regression Rate-of-Change (LRR). Hasil penelitian menunjukkan bahwa nilai tertinggi dari Linear Regression Rate-of-Change (LRR) selama periode 20 tahun adalah sebesar 50,9 m/tahun sedangkan nilai terendah sebesar -35,81 meter/tahun. Nilai rata-rata EPR dan NSM selama periode 20 tahun adalah sebesar -0,07 m/tahun dan -1,14 meter. Berdasarkan studi ini, dampak dari perubahan garis pantai yang disebabkan abrasi dan akresi adalah adanya peningkatan dan penurunan luas wilayah. Bentuk mitigasi perubahan garis pantai di Kabupaten Kendal yakni dengan pembangunan breakwater dan penanaman hutan mangrove. Abstract Monitoring shoreline change due to accretion and abrasion processes is one of the efforts to protect the maritime boundary of Kendal Regency. Five multi-temporal Landsat 7 ETM + images spanning 20 years (2000-2020) is used in the tudy for the analysis of shoreline change in Kendal Regency. This study aims to investigate the shoreline change, analyze the impact, and propose mitigation of shoreline change in Kendal Regency as well. Digital Shoreline Analysis System (DSAS) is utilized for the analysis of the shoreline change through Net Shoreline Movement (NSM), End Point Rate (EPR), and Linear Regression Rate-of-Change (LRR). The result shows that the highest value of the Linear Regression Rate (LRR) for 20 years is 50.09 m/year and the lowest value of LRR is -35.81 m/year. The average EPR and NSM are -0.07 m/years and -1.14 m. From this study, it can be observed that the impact of shoreline change induced by accretion and abrasion are the addition and subtraction of the predetermined area. The impacts can be mitigated by building breakwaters and planting mangroves.

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