No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
REMOTE SENSING APPLICATION FOR COASTLINE DETECTION IN CA MAU, MEKONG DELTA
... Both accretion and erosion issues greatly influence human lives, agriculture and aquaculture, natural resources, and waterway transport activities along the coastal zone. Therefore, shoreline mapping and change detection are essential tasks [2]. Over the years, several approaches have been developed to detect and monitor the shoreline evolution. ...
... Thus, a gap filling preprocessing step was done by using the NASA Landsat gapfill tool linked to ENVI software program. The spectral data across gaps in SLC off images was interpolated from a gap free image [2]. ...
Giens double tombolo linking Giens island to the mainland is a unique geomorphological formation in the world. However, its existence has been threatened by coastal erosion, especially in the eastern part of this tombolo. The investigation of historical shoreline changes along the eastern Giens tombolo were carried out applying the integration of satellite remote sensing and geographic information system (GIS) techniques. Additionally, the combination of the Digital Shoreline Analysis System (DSAS) and linear regression method was used to predict the location of future shorelines. The results obtained from the analysis of shoreline position showed that the average annual change rate along the eastern Giens tombolo varied around +0.18 m/yr during the duration from 1973 to 2015, revealing a general progradation trend. Even though accretion is dominant, there are some local areas undergoing severe erosion. The most severely vulnerable areas were Les Cabanes du Gapeau, the south of Ceinturon, Pesquiers, and the north of La Capte with the maximum change rates of −1.05 m/yr, −0.77 m/yr, −0.44 m/yr, and −0.29 m/yr, respectively. The change analysis of shorelines in 2020 and 2050 also reveals these severely eroded areas. On the other hand, this work demonstrates that both natural factors and human activities are the main causes of the shoreline changes in the eastern Giens tombolo.
... -Chiết tách đường bờ áp dụng phương pháp phân tích giữa giá trị ngưỡng và ảnh tỷ số [5], đường bờ được tách ra để xác định đường đê bao áp dụng theo công thức: ...
The study was conducted to monitor spatial fluctuations of dikes affecting the rice crop structure and evaluate changes in rice crop structure inside and outside the dikes in the Long Xuyen Quadrangle in the period 2005-2020. That serves as a basis for assessing the current status of flood control and the changing trend of rice production in the region in the future. The study uses LANDSAT images and applies the normalized difference water index (NDWI) and shoreline extraction to determine the current condition of dikes in the Long Xuyen Quadrangle region, while combining a series of normalized difference vegetation index (NDVI) on moderate resolution imaging spectroradiometer (MODIS) image data to determine the structure of rice crops in 2005 and 2020. The results show that the embankment length increased by 1,910.15 km compared to 2005 and the natural embankment area increased to 123,020.31 ha (accounting for 24.63% of the area’s natural area) in the period 2005-2020. The farming system in the study area impacted by flood prevention dike changes from other crops to triple-rice crop cultivation. Specifically, the total area of the other cultivation types converted into triple-rice crop cultivation is 90,904.77 ha, accounting for 51.92% of the total area of structural transformation of farming types, concentrated in districts with large dike areas such as Thoai Son, Chau Phu, and Chau Thanh districts (An Giang province). The research results contribute to supporting environmental management and orienting rice production trends in the region in the future.
... In the past, shoreline assessment was conducted by field survey method with traditional tools and equipment, but now we can perform shoreline measurement with modern equipment such as a global positioning system GPS, or camera system and information sources from satellite images. The data source from satellite images will be input into a GIS for semi-automatic processing, analysis, and assessment of shoreline changes [9]. Some previous works on Ca Mau Cape in the short period as 1995 -2010 due to historic data unavailable [10], additionally, other studies have not presented detailed quantitative shoreline changes at commune level [10]. ...
Coastal erosion as well as loss of aquaculture, cultivated and residential lands are of great concern in the Mekong Delta, especially in the Ca Mau Cape region. Historical map data and remote sensing images such as Landsat data combined with GPS field surveys are the optimal methods for assessing shoreline changes including coastal erosion and sedimentation. The 57-year coastline change during the period from 1965 to 2022 has been described through the processing of topographic map data published in 1965 and a series of Landsat-1 to Landsat-8 images collected in 1973, 1993, 2003, and 2022. The study found that the northeast of the study area in Cho Thu hamlet, Tam Giang Tay commune was the place where the largest erosion reached an annual average of 42.4 m/year. Due to the development program of afforestation, largest sediment reaches an annual average of 88.7 m/year in Ca Mau Cape National Park in Lach Vam hamlet, Dat Mui commune. However, during the 57-year period, coastal erosion has caused a loss of 1,714 hectares of land or 2.60% of the total area. Results from this work also suggest that the accuracy of the shoreline studies should be improved by using higher satellite data spatial resolution and the GPS system with dual frequencies for Real-time Kinematics (RTK) for coordinate positioning measurement.
... Chiết tách đường bờ: Nghiên cứu chiết tách đường bờ được xác định là đường đê bao dựa trên ranh giới giữa vùng ngập và không ngập trên ảnh LANDSAT, được thu thập vào các tháng ngập lũ (từ tháng 8 đến tháng 11 hàng năm) bằng cách áp dụng phương pháp phân tích giữa giá trị ngưỡng và ảnh chỉ số NDWI theo công thức (3) (Claire et al., 2012). ...
Mục tiêu nghiên cứu nhằm theo dõi và đánh giá tác động của đê bao ngăn lũ lên hiện trạng canh tác lúa vùng Đồng Tháp Mười (ĐTM) năm 2000 và 2019. Phương pháp nghiên cứu sử dụng ảnh LANDSAT áp dụng thuật toán ảnh chỉ số khác biệt nước (NDWI) và trích rút đường bờ và bộ dữ liệu ảnh MODIS áp dụng chuỗi ảnh chỉ số thực vật (NDVI) và phân loại phi giám sát (ISODATA) trong 2 năm 2000 và 2019. Độ tin cậy kết quả phân loại ảnh khá cao với độ chính xác toàn cục >85% và hệ số Kappa >0,7 cho 2 năm 2000 – 2019. Kết quả nghiên cứu cho thấy diện tích canh tác lúa trong vùng đê bao ngăn lũ đã tăng thêm khoảng 126.139,40 ha (19,36%). Vùng được bao đê ở ĐTM không còn canh tác lúa 1 vụ và hầu hết đã chuyển đổi sang canh tác 2 hoặc 3 vụ lúa và gia tăng lần lượt năm 2019 là 81.229,47 ha (39,18%) và 126.142,15 ha (60,82%) so với năm 2000. Vùng chuyển đổi nhiều nhất là huyện Tháp Mười và Cao Lãnh tỉnh Đồng Tháp, huyện Mộc Hóa tỉnh Long An, huyện Cái Bè và Cai Lậy tỉnh Tiền Giang.
... The NDVI multi-spectral processing algorithm is the most widely used in mapping analysis (El Kafrawy et al., 2017;Mukhopadhyay et al., 2012). In this study, the limitation of the NDVI algorithm caused errors at several locations, especially in locations with high turbidity water, which then need to be corrected manually (Casse et al., 2012). ...
Cirebon Coastal Area (CCA), which covers Cirebon City and Cirebon District, is an area located on the north coast of Java Island, Indonesia. The area was among the coastal areas with a high-density population in Indonesia. Human activities in this area, which are dominated by industries, fisheries, and agriculture, strongly influenced the coastal environmental conditions. One of the effective and accurate ways to monitor the coastal environmental conditions is to utilize remote sensing technology which has grown significantly in recent years. Although various studies have been conducted, slightly different results were shown and indicated that the coastal dynamics in CCA were not fully understood yet. This research provides a comprehensive analysis with the aim to comprehend the complete pattern of coastal dynamics in CCA. Analysis of coastal dynamics has been carried out by using a combination of Landsat and Google Earth data. This robust combination allowed to cover a long-time span (1996-2020), periodic, and high-resolution data analysis Results indicated that along the CCA shoreline the accretion was dominated rather than the erosion. While on the eastern area showed more dynamic changes rather than the western area, especially at Losari, Pangenan, and Lemahwungkuk sub-districts.
... in extracting water bodies and differentiating between dry and moist soils. The SWIR1 band displays a high contrast between land and water classes and discriminates moisture contents in soil and vegetation [11]. Other studies have used the NIR band [12], whereas we have selected both the green (NIR) and shortwave (SWIR1) bands, achieving significantly suitable main results, particularly during the analysis of images from 1984. ...
The current study highlights the usefulness of satellite images in monitoring and predicting changes occurring on shorelines through a bi-dimensional strategy—data based and situational based. Three coastal areas of Jeddah city were selected as the study areas: Salman Bay, Sharm Abhar and Jeddah Port. For the data-based dimension, data collected through satellite images were used in the analysis covering the period from 1972 to 2016. Four regression models were used to study the variation in the coastal borders of the study area. Predictions for the next 9 years, i.e., up to 2025, were carried out using the four regression models. The results revealed that an area reduction has been witnessed in all the areas under study. Another fact that came to the limelight is the proximity of the objective results with the expectations of experts, thus providing credence to the appropriateness of employed statistical models. For situational-based dimension effects, various anthropogenic activities and geo-environmental natural processes in the study area were identified. Based on the findings of the study, continuous monitoring of the coastal areas is suggested along with maintaining a concrete database. The proposed techniques can be extended to study coastal reduction and extension in other regions as well.
... The erosion and accretion processes, especially erosion, greatly affect human life, cultivation and aquaculture, natural resources, and waterway transport activities along the coastal zone. Correspondingly, shoreline mapping and change detection are essential tasks in safe navigation, coastal and marine resource management, environmental protection, and sustainable coastal development and planning [1] . ...
The present study aims to utilize the combination of remote sensing and Geographic Information System (GIS) techniques coupled with the Digital Shoreline Analysis System (DSAS) to investigate the historical shoreline changes as well as to predict the position of future shoreline in Almanarre beach which is being threatened by erosion. The results indicate that the average annual change rate along Almanarre beach was about -0.24 m/year over the period of 1973-2015, showing an erosive trend. Moreover, the maximum erosion rate of -0.86 m/year was observed near Landmark B17. The predicted shoreline change in 2020 is approximately -0.05 m/year, whereas in 2050 it is estimated about -0.22 m/year. The highest erosive areas in future are estimated around Landmarks B06-08 and Landmarks B16-18 with the maximum recession rates of -0.89 m/year and -0.94 m/year, respectively. This research should be useful for predicting the shoreline change trend as well as planning for coastal protection and management.
... The atmospheric correction process was conducted using the COST model that indicated the accuracy of correction algorithms. The contrast between the land and water was highlighted from Alesheikh's research to meet to South Vietnam condition (Casse et al., 2012). Then, the shape of a river was digitized by using convert vector tool in QGIS. ...
In this study, the method of Fault Movement Potential (FMP) proposed by Lee et al. (1997) is used to assess the Surface water resources played a fundamental role in sustainable development of agriculture and aquaculture. They were the main sectors contributing to economic development in the Vietnamese Mekong Delta. Monitoring surface water quality was also one of the essential missions especially in the context of increasing freshwater demands and loads of wastewater fluxes. Recently, remote sensing technology has been widely applied in monitoring and mapping water quality at a regional scale replacing traditional field-based approaches. The aims of this study were to assess the application of the Landsat 8 (OLI) images for estimating Chemical Oxygen Demand (COD) as well as detecting spatial changes of the COD concentration in river reaches of the Binh Dai district, Ben Tre province, a downstream area of the delta. The results indicated the significant correlation (R=0.89) between the spectral reflectance values of Landsat 8 and the COD concentration by applying the Artificial Neuron Network (ANN) approach. In addition, the spatial distribution of the COD concentration was found slightly exceeded the national standard for irrigation according to the B1 column of QCVN 08:2015.
Kien Giang is one of the coastal provinces in the Mekong Delta which is facing the problem of coastal erosion to affect people’s life in the coastal area. This project aims to monitor shoreline and to assess landslide and accretion situation in the period from 1975 to 2015 in the coastal area of Kien Giang province. The study applied Normalized Difference Water Index (MNWI) method and water level extraction using LANDSAT imagery from 1975 to 2015 for highlight the shoreline. Thus, analysis was identified erosion and accretion areas based on shoreline changes and land use influenced by landslides and deposition. The results show to create shoreline changes from 1997 to 2015 in the coastal area of Kien Giang province. A landslide occurred in the west from Nguyen Viet Khai commune to Thuan Hoa commune and Nam Yen commune to Vinh Hoa Hiep commune, Rach Gia city, Kien Giang province. An accretion situation was determined in the areas from Thuan Hoa commune, An Minh district to Nam Thai commune, An Bien district, Kien Giang province, Rach Gia sea encroachment at Rach Gia town and Ha Tien encroachment area at Ha Tien town, Kien Giang province. In general, the coastal area of Kien Giang province has a predominant tendency of accretion, however, the occurrence of erosion and accretion are happened interlacing in the coastal area at Kien Giang province.
This book constitutes the refereed post-conference proceedings of the International Conferences ICCASA and ICTCC 2019, held in November 2019 in My Tho, Vietnam. The 20 revised full papers presented were carefully selected from 33 submissions. The papers of ICCASA cover a wide spectrum in the area of context-aware-systems. CAS is characterized by its self- facets such as self-organization, self-configuration, self-healing, self-optimization, self-protection used to dynamically control computing and networking functions. The papers of ICTCC cover formal methods for self-adaptive systems and discuss natural approaches and techniques for computation and communication.
Flooding is a natural risk, large floods have occurred almost every year. These are major issues that researchers are interested and to identify flooded areas or assess the risk of flooding, the researchers using image LiDAR or image RADAR to flood mapping, flood risk management, observation and change detection in floodable area. However, flood modeling or flood assessment don’t solve the problem of flood risks. Therefore, in this paper we propose a new approach of processing methodology based on time series analysis that enables predicting of the floodable areas in the Mekong Delta using new satellite images such as Lansat 7 ETM+, Landsat 8 OLI and sentinel-2 MSI.
Kien Giang is one of the coastal provinces in the Mekong Delta which is facing the problem of coastal erosion to affect people’s life in the coastal area. This project aims to monitor shoreline and to assess landslide and accretion situation in the period from 1975 to 2015 in the coastal area of Kien Giang province. The study applied Normalized Difference Water Index (MNWI) method and water level extraction using LANDSAT imagery from 1975 to 2015 for highlight the shoreline. Thus, analysis was identified erosion and accretion areas based on shoreline changes and land use influenced by landslides and deposition. The results show to create shoreline changes from 1997 to 2015 in the coastal area of Kien Giang province. A landslide occurred in the west from Nguyen Viet Khai commune to Thuan Hoa commune and Nam Yen commune to Vinh Hoa Hiep commune, Rach Gia city, Kien Giang province. An accretion situation was determined in the areas from Thuan Hoa commune, An Minh district to Nam Thai commune, An Bien district, Kien Giang province, Rach Gia sea encroachment at Rach Gia town and Ha Tien encroachment area at Ha Tien town, Kien Giang province. In general, the coastal area of Kien Giang province has a predominant tendency of accretion, however, the occurrence of erosion and accretion are happened interlacing in the coastal area at Kien Giang province.
An attempt is being made to elucidate the effect of shoreline changes ersion and accretion along are IRS (1971) used for this study. The kind and extent of shoreline changes were investigated by using km 2 , 1991 to 2001 was 4.91, 2001 to 2006 was 0.39 and 2006 to 2012 was 1.27 km 2 respectively. 2 , No 2 accretion were also observed in specific geographical areas such as beach, plantation, land with dominates, are analyzed and presented in this paper. The study results revealed that 3.21 km 2 area erosion Keywords:
Coastal is an area that is influent by two processing factors that are marine and land dynamic process. In this area, occurs a complex dynamic process, which caused the relatively quick changes. The use of remote sensing data to study the process that occur in the area will get some helpful information to know the changes that happened, e.g. to study coastline dynamic. The need of this kind information is useful by countries that have long coastline and have so many islands just like Indonesia. This study use Landsat 7 data with ETM+ sensor, supported by Landsat 5 (TM), bathymetric map and tidal data from the study case area of Riau Archipelago especially Batam Island and surrounding. From this study can be summarize that the information on the coastline can be obtain in easy and accurate with combining band ratio of 4/2 and 5/2. The result has to be corrected with visual interpretation of color composite 543 RGB by visual editing to reduce errors from digital processing. The result also has to be corrected with tidal data because the information are obtain from different tidal time, which are usually different with the standard tidal data that are used to determine the coastline. Preface
The coastal zone represents varied and highly productive ecosystems such as mangroves, coral reefs, sea grasses and sand dunes. These ecosystems are under pressure on account of increased anthropogenic activity on the coast, as a result of globalisation. It is necessary to protect these coastal ecosystems to ensure sustainable development. This requires information on habitats, landforms, coastal processes, water quality, natural hazards on a repetitive basis. In India, remote sensing data, especially Indian Remote Sensing (IRS) data, having moderate (23-36 m) to high spatial resolution (6 m), have been used to generate database on various components of coastal environment of the entire country. However, the moderate resolution data provide macro-level information on 1:250,000 and 1:50,000 scale about the condition of habitats, type of landforms and areas under erosion and deposition. The major advantage of remote sensing data is monitoring of change periodically. The combination of moderate and high-resolution data provided detailed coastal land use maps on the 1:25,000-scale for implementing coastal regulation measures. The classification accuracy have been achieved is 85 per cent or better at 90 per cent confidence level. Mangrove areas were classified up to community level through contextual editing. Various zones of coral reef were identified, however, species level information is not possible to generate using such data. The knowledge about bio-optical properties of water is vital for coral reef and sea grass bed monitoring. The OCEANSAT I (IRS P4) Ocean Colour Monitor (OCM) data provide useful information on the phytoplankton and suspended sediments. The information on phytoplankton and sea surface temperature (SST) has been used to predict potential fishery zones routinely. The information on sediments provides some insight in to the movement of sediments along the coast. Satellite-derived derived information were integrated with the other collateral information through GIS to select sites for aquaculture, zoning of coastal zone for regulatory purpose and assess possible impact of sea level rise. Realising the value of the remote-sensing derived information, the state and central agencies responsible for the conservation of these ecosystems are increasingly adopting remote sensing data for their routine use.
Analysis of shoreline variability and shoreline erosion-accretion trends is fundamental to a broad range of investigations undertaken by coastal scientists, coastal engineers, and coastal managers. Though strictly defined as the intersection of water and land surfaces, for practical purposes, the dynamic nature of this boundary and its dependence on the temporal and spatial scale at which it is being considered results in the use of a range of shoreline indicators. These proxies are generally one of two types: either a feature that is visibly discernible in coastal imagery (e.g., high-water line [HWL]) or the intersection of a tidal datum with the coastal profile (e.g., mean high water [MHW]). Recently, a third category of shoreline indicator has begun to be reported in the literature, based on the application of image-processing techniques to extract proxy shoreline features from digital coastal images that are not necessarily visible to the human eye. Potential data sources for shoreline investigation include historical photographs, coastal maps and charts, aerial photography, beach surveys, in situ geographic positioning system shorelines, and a range of digital elevation or image data derived from remote sensing platforms. The identification of a "shoreline" involves two stages: the first requires the selection and definition of a shoreline indicator feature, and the second is the detection of the chosen shoreline feature within the available data source. To date, the most common shoreline detection technique has been subjective visual interpretation. Recent photogrammetry, topographic data collection, and digital image-processing techniques now make it possible for the coastal investigator to use objective shoreline detection methods. The remaining challenge is to improve the quantitative and process-based understanding of these shoreline indicator features and their spatial relationship relative to the physical land-water boundary.
Coastal zone detection is an important task in sustainable development and environmental protection. For coastline zone monitoring, extraction and analysis of coastline changes are an important task. Detection of coastline changes by satellite images and remote sensing methods became increasingly important over the recent decades. This study extracted mean high tide lines of the Yellow River estuary from Landsat MSS, TM and ETM+ data from 1976 to 2005, totaling 27 scenes. Results show that: The general pattern of accretion-erosion of the entire estuary was divided into four stages: The rapid accretion stage (1976-1986), accretion-erosion adjustment stage (1985-1996), slow erosion stage (1997-2003), and slow accretion stage (2004-present). The relation between the area and length is presented in Fig.7. There is a clear quadratic trend between the area and length. The relationship has a correlation coefficient, R=0.862, and significant level, P=0.001. For the Q8 course estuary, the total area increased by 8.52 km2 with a mean net accretion rate of 0.95 km2/a during the period from 1996 to 2005. Due to the low runoff and sediment load, the Yellow River delta could be eroded naturally for several years in the future.
The normalized difference vegetation index (NDVI) has been widely used for remote sensing of vegetation for many years. This index uses radiances or reflectances from a red channel around 0.66 μm and a near-IR channel around 0.86 μm. The red channel is located in the strong chlorophyll absorption region, while the near-IR channel is located in the high reflectance plateau of vegetation canopies. The two channels sense very different depths through vegetation canopies. In this article, another index, namely, the normalized difference water index (NDWI), is proposed for remote sensing of vegetation liquid water from space. NDWI is defined as , where ϱ represents the radiance in reflectance units. Both the 0.86-μm and the 1.24-μm channels are located in the high reflectance plateau of vegetation canopies. They sense similar depths through vegetation canopies. Absorption by vegetation liquid water near 0.86 μm is negligible. Weak liquid absorption at 1.24 μm is present. Canopy scattering enhances the water absorption. As a result, NDWI is sensitive to changes in liquid water content of vegetation canopies. Atmospheric aerosol scattering effects in the 0.86–1.24 μm region are weak. NDWI is less sensitive to atmospheric effects than NDVI. NDWI does not remove completely the background soil reflectance effects, similar to NDVI. Because the information about vegetation canopies contained in the 1.24-μm channel is very different from that contained in the red channel near 0.66 μm, NDWI should be considered as an independent vegetation index. It is complementary to, not a substitute for NDVI. Laboratory-measured reflectance spectra of stacked green leaves, and spectral imaging data acquired with Airborne Visible Infrared Imaging Spectrometer (AVIRIS) over Jasper Ridge in California and the High Plains in northern Colorado, are used to demonstrate the usefulness of NDWI. Comparisons between NDWI and NDVI images are also given.
Coast is a unique environment in which atmosphere, hydrosphere and lithosphere contact each other. Coastline is one of the most important linear features on the earth’s surface, which display a dynamic nature. Coastal zone, and its environmental management requires the information about coastlines and their changes. This paper examines the current methods of coastline change detection using satellite images. Based on the advantages and drawbacks of the methods, a new procedure has been developed. The proposed procedure is based on a combination of histogram thresholding and band ratio techniques. The study area of the project is Urmia Lake; the 20th. largest, and the second hyper saline lake in the world. In order to assess the accuracy of the results, they have been compared with ground truth observations. The accuracy of the extracted coastline has been estimated as 1.3 pixels (pixel size=30 m). Based on this investigation, the area of the lake has been decreased approximately 1040 square kilometers from August 1998 to August 2001. This result has been verified through TOPEX/Posidon satellite information that indicates a height variation of three meters.
Waterline technique based on satellite remote sensing is potentially one of the most effective tools for studying changes in tidal flat environment and coastlines. However, multi-temporal waterlines obtained from satellite images are often difficult to compare directly because fluctuant tidal conditions may produce different elevation of waterlines. To overcome the difficulty, this study developed a comparable waterline solution to estimate active lateral evolutions using TM satellite images at different tide conditions. Owing to the dynamic properties, the Yangtze River mouth was selected as the case example to test the suitability of the approach, and totally four time slices were partitioned during 1987–2004 for investigating coastline changes. The first step of this technique is to digitize waterlines with various elevations labeling in a time slice. In the second step, the waterlines were merged to generate DEMs and contour maps using the linear gridding interpolation method. In the last step, any interested contour line may be extracted from DEMs and used for comparison of tideland changes. To evaluate the errors in digitizing and interpolation process, quantitative checks were examined after the DEMs were constructed. In order to monitoring the rate of coastline spread, a proposed approach for estimating mean coastline spread distance between two time spans is developed in this paper. To conclude, this work demonstrates the importance of TM/ETM images to provide high-frequency historical topography and morphodynamics information for coastal monitoring and evaluation.
Shoreline Change Monitoring in Coastal India, Using Remote Sensing and GIS Tools
- K Selvanayagam
Selvanayagam, K., 2008. Shoreline Change Monitoring in Coastal India, Using Remote Sensing and
GIS Tools. EnzineArticles.com, 29 Aug 2008, available on:
http://ezinearticles.com/?ShoreLine-Change-Monitoring-in-Coastal-India,-Using-Remote-Sensing-and-GIS-Tools&id=1154397