共查询到19条相似文献,搜索用时 109 毫秒
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何裕 《测绘与空间地理信息》2022,(2):156-160
海岸线是海洋和陆地的分界线,其中海岛岸线与海岛海岸带管理、周围海域使用等活动密切相关.如何提高海岛岸线测量效率及精度,为海岛海岸带的开发与保护提供技术支持显得尤为重要.本文以浙江省舟山市岱山岛为研究区,以Sentinel-2遥感影像为数据源,利用面向对象的隶属度函数分类对岱山岛海岸线进行自动提取,再根据海岸线界定标准对... 相似文献
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基于RS和GIS技术对铁山港地区4个时期的Landsat卫星遥感数据进行处理,分析岸线特征,提取海岸线,研究该区海岸线近20年来(1987年~2006年)的变化特征。结果显示:研究区海岸线总体处于向海推进状态,其变化主要受人为因素影响。岸线变化的主要表现在铁山港与丹兜海湾顶两侧,以养殖开发、港口码头建设为主。 相似文献
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利用卫星遥感数据提取地物信息,已成为遥感观测地物的一种重要手段.但在地物信息提取时由于多种因素的干扰,导致部分地物信息丢失.如何解译出地物的细部信息成为遥感信息提取的关键.利用Landsat7遥感数据为例,探讨了提取水体专题信息的方法,通过对遥感影像进行最佳波段组合、色彩变换、分类后对水体信息进行提取,效果较好. 相似文献
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海岛岸线遥感立体测图精细测量方法 总被引:2,自引:0,他引:2
提出了一种海岛岸线遥感测图精细测量新方法,该方法直接基于理论定义的海岸线,利用航空影像瞬时水涯线数据在立体测图环境中提取瞬时水位高程;利用海岛周边精密海潮模型和瞬时水位高程推算海岛岸线高程;最后依据海岛岸线高程,采用立体测图方法测制海岛岸线的平面位置。该方法确保了海岛岸线成果的唯一性和连续性,适合大比例尺的大陆海岸线和海岛岸线测量。测试结果显示,在较高精度海潮模型和海面地形支持下,海岛岸线高程精度优于0.2 m,可满足1:2000测图要求。 相似文献
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在遥感图像处理中,通过遥感影像判别识别各种目标是其发展的一个重要环节,无论是专业信息的提取、动态变化监测,还是专题地图的制作和遥感数据库的建立等都离不开所需信息的提取,因此影像信息的提取是影像图像处理的研究重点。掩膜(MASK)技术就是运用地物及影像的特点将影像中的地物提取出来。本文主要介绍地物及影像的特点,运用MASK技术将影像中的水提取出来,并将提取成果与原始影像进行比较分析。 相似文献
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Funafuti Atoll, Tuvalu is located in the southwestern Pacific Ocean, which has experienced some of the highest rates of global sea-level rise over the past 60 years. Atoll islands are low-lying accumulations of reef-derived sediment that provide the only habitable land in Tuvalu, and are considered vulnerable to the myriad possible impacts of climate change, especially sea-level rise. This study examines the shoreline change of twenty-eight islands in Funafuti Atoll between 2005 and 2015 using 0.65 m QuickBird, 0.46 m WorldView-2, and 0.31 m WorldView-3 imagery using an image segmentation and decision tree classification. Shoreline change estimates are compared to previous study that used a visual interpretation approach. The feasibility of estimating island area with Landsat-8 Operational Land Imager (OLI) data is explored using CLASlite software. Results indicate a 0.13% (0.35 ha) decrease in net island area over the study time period, with 13 islands decreasing in area and 15 islands increasing in area. Substantial decreases in island area occurred on the islands of Fuagea, Tefala and Vasafua, which coincides with the timing of Cyclone Pam in March, 2015. Comparison between the WorldView-2 shoreline maps and those created from Landstat-8 indicate that the estimates tend to be in higher agreement for islands that have an area > 0.5 ha, a compact shape, and no built structures. Ten islands had > 90% agreement, with percent disagreements ranging from 2.78 to 100%. The methods and results of this study speak to the potential of automated EoV shoreline monitoring through segmentation and classification tree approach, which would reduce down data processing and analysis time. With the growing constellation of high and medium spatial resolution satellite-based sensors and the development of semi or fully automated image processing technology, it is now possible to remotely assess the short and medium-term shoreline dynamics on dynamic atolls. Landsat estimates were reasonably matched to those derived from fine resolution imagery, with some caveats about island size and shape. 相似文献
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Shoreline and coral reef ecosystem changes in gulf of Mannar, Southeast coast of India 总被引:1,自引:0,他引:1
M. Thanikachalam S. Ramachandran 《Journal of the Indian Society of Remote Sensing》2003,31(3):157-173
Changes in shoreline, coral reef and seafloor have been mapped using remote sensing satellite data of IRS LISS-III (1998),
IRS LISS-II (1988), Survey of India Topographic sheet (1969), Naval Hydrographic Chart (NHO) 1975 and bathymetry data (1999)
with ARC-INFO and ARC-VIEW GIS. The analysis of multi-date shoreline maps showed that 4.34 and 23.49 km2 of the mainland coast
and 4.14 and 3.31 km2 areas of island coast have been eroded and accreted, respectively, in the Gulf of Mannar. The analysis of multi-date coral
reef maps showed that 25.52 km2 of reef area and 2.16 km2 of reef vegetation in Gulf of Mannar have been lost over a period of ten years. The analysis of multi-date bathymetry data
indicates that the depth of seafloor has decreased along the coast and around the islands in the study area. The average reduction
of depth in seafloor has been estimated as 0.51m over a period of twenty four years. The increased suspended sediment concentration
due to coastal and island erosion, and raised reef due to emerging of coast by tectonic movement are responsible for coral
reef degradation in the Gulf of Mannar. Validation by ground truth has confirmed these results. 相似文献
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利用TM卫星多时相数据,采用变化探测技术研究了官厅水库1988—2001年时间段库区边岸的动态变化。对库区淤积、边岸侵蚀等问题进行了探讨;结合水位差数据,提出边岸坡度和边岸稳定性的遥感时空分析方法和判据;分析了上述问题对官厅水库水资源利用的影响。边岸稳定性判别方法可应用于湖泊、海洋的滩涂地区。 相似文献
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官厅水库的遥感动态变化探测及边岸稳定性判别 总被引:2,自引:0,他引:2
利用TM卫星多时相数据,采用变化探测技术研究了官厅水库1988—2001年时间段库区边岸的动态变化。对库区淤积、边岸侵蚀等问题进行了探讨;结合水位差数据,提出边岸坡度和边岸稳定性的遥感时空分析方法和判据;分析了上述问题对官厅水库水资源利用的影响。边岸稳定性判别方法可应用于湖泊、海洋的滩涂地区。 相似文献
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This study describes a method to map shoreline indicators on a sandy beach. The hypothesis is that, on this beach, spectral albedo is predominantly determined by moisture content and water lines can, therefore, be detected as albedo contrasts. A laboratory experiment is performed to relate moisture content to image albedo, and supervised edge detection is subsequently used to map the shoreline indicators with remote sensing imagery. The algorithm is tested with data from visible, near-infrared and shortwave-infrared wavelength regions. These results are compared to shoreline indicators obtained by a field survey and a shoreline indicator derived from a digital elevation model. Both the water line present when the imagery was acquired, as well as the maximum extent of the last flood, can be detected as a single edge. Older high water lines are confused with the last high water line and appear dispersed, as there are multiple debris lines present on the beach. The low water line, usually in saturated sand, also appears dispersed due to the presence of channels and troughs. Shorelines are constant moving boundaries, which is why shoreline indicators are used as a proxy. Unlike a mathematical indicator that is based on an elevation model, our method is more sensitive to the dynamic nature of shorelines. Supervised edge-detection is a technique for generating reproducible measurements of shoreline indicator positions over time, and aids in the monitoring of coastline migration. 相似文献
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Spatial modeling using high resolution image for future shoreline prediction along Junput Coast,West Bengal,India 总被引:1,自引:0,他引:1
National policies and legal decisions are very much dependent on the position of the shoreline. Shoreline change rates are frequently employed to summarize historical shoreline movements. This also helps to predict the future position of the shoreline based on the perceived historical trends. In this regard, the future shoreline positions at both the long-term, that is 2050, and short-term, that is 2015, time interval was predicted using the End Point Rate (EPR) model along the Junput Coast of West Bengal, India. The whole project work was divided into five parts. The first part showed the detection of shoreline from satellite data like IRS LISS Ⅳ and Landsat 7 ETM+ and from the Survey of India Toposheet. The second part gave the glimpse of the dynamic segmentation of the shoreline to get the dynamically segmented nodal points along the shoreline. Shoreline prediction for the years 2015 and 2050 using End Point Rate (EPR) model was done in the third part. In the fourth part, Coastal Terrain Model (CTM) was prepared, and the digital shoreline estimated. The model result was validated and accuracy assessed with respect to the GPS data collected from the field at the fifth stage. Finally at the end of the present work, limitations of the project and the future scope of the work was sited. 相似文献
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E. Saranathan R. Chandrasekaran D. Soosai Manickaraj M. Kannan 《Journal of the Indian Society of Remote Sensing》2011,39(1):107-115
Coastal zone is very dynamic, being the meeting place of land and sea water. The development in coastal area and subsequent
population growth have given rise to problems such as erosion, sedimentation, saltwater intrusion, degradation of natural
resources, etc. Satellite data has proved to be more appropriate for change detections quantifying and monitoring coastal
zones compared to conventional sources. An attempt is being made to elucidate the effect of shoreline changes with reference
to the spatial and field data observed along the Tharangampadi area. The base map was prepared on 1:50,000 scale for delineation
and identification of shoreline changes. The spatial variability of shoreline changes are studied using IRS 1B LISS-II 1991,
IRS 1C LISS-III 2004 and IRS P6 LISS-IV and IRS 1D PAN merge data 2006. The corresponding Survey of India toposheets of 1852,
1972 and survey and land record village map of 1918 also supplemented for this study. The kind and extent of shoreline changes
were investigated by using GPS during ground truth verification. The results are analyzed and presented in this paper. The
study results revealed that 180 m receding of the shoreline occurred in the past 155 years. 相似文献