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1.
The waterline detection method (WDM) based on satellite images is one of the most effective methods for constructing digital elevation models (DEMs) for tidal flats. The general practicability of the WDM has been demonstrated in previous studies for small areas. This article attempts to generate a DEM over a large offshore sandbank with a tidal flat area of more than 620 km2 by integrating the conventional WDM with a hydraulic model and multitemporal satellite images. For illustration purposes, a case study was conducted at the Dongsha sandbank, one of the largest sandbanks among the radial tidal sand ridges of Jiangsu Province, China. In this study, 34 multitemporal satellite images acquired at different tidal phases in 2006 were analyzed to detect the waterlines. The water level at each satellite overpass moment was simulated by a south Yellow Sea hydraulic model, and discrete waterline points were combined with the corresponding water levels to produce a topographic map. Compared with the DEM produced during the same period by the airborne light detection and ranging (LiDAR) data, the DEM derived from WDM effectively contains the average height error within 47 cm, which is satisfactory. All of these findings may be useful for researchers and local authorities, as the findings could be used as a reference for sandbank evolution research or to support environmental management, coast protection, and storm forecasting. 相似文献
2.
提出并实现了基于遥感技术和多站点潮位插值的淤泥质海岸线推算方案。利用多时相遥感影像提取出人工岸线和瞬时水边线,在控制站点潮汐调和分析的基础上,利用潮汐线性分带插值校正处理,赋予水边线离散点在影像成像时刻的实际潮位,进而根据三角函数相似性原理推算出岸滩的平均坡度和平均大潮高潮点位置,连接形成自然岸线,最终根据自然岸线与人工岸线合成得到海岸线的空间分布。实践应用证明,该方案得到的海岸线与现场测定的平均大潮高潮痕迹点相吻合,可为快速确定淤泥质海岸岸线,监测岸滩资源的空间变化提供方法与数据支撑。 相似文献
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4.
平缓潮滩的测绘受到潮汐和淤泥的双重影响,难以进行大区域的人工作业。探讨利用序列遥感影像构建潮滩DEM的技术方法。基于多时相BJ-1小卫星自动提取水边线,利用中国近海高分辨率潮位网格,与卫星过境时刻的水边线进行空间关联与内插,生成带有高程值的系列水边点,并以此来构建潮滩地形三角网,最后生成格网潮滩DEM。与现场RTK验证的三个剖面的高程相比,其高程绝对误差均值小于0.2m。结果表明,应用中分辨率遥感影像进行淤泥质潮滩地形反演可以达到一定比例尺的制图精度。 相似文献
5.
GF-3号SAR卫星遥感围填海监测方法研究——以大连金州湾为例 总被引：1，自引：0，他引：1
依据不同围填海类型在高分三号(GF-3)合成孔径雷达(synthetic aperture radar,SAR)卫星遥感影像上可分性,建立围填海遥感分类体系及相应的围填海类型解译标志,进而分析SAR图像岸线提取方法,构建GF-3围填海监测技术流程。采用几何主动轮廓模型进行GF-3 SAR影像自动提取海岸线,获得围填海专题图。通过外业精度调查验证GF-3 SAR卫星遥感影像可以有效获取围填海信息。 相似文献
6.
江苏中部淤泥质海岸岸线变化遥感监测研究 总被引：4，自引：0，他引：4
海岸线监测是了解海岸冲淤变化的基础。针对淤泥质海岸潮间带坡度平缓的特点,考虑到潮汐对遥感海岸线监测的影响,基于多潮位站插值校正的水边线离散点潮位赋值及坡度计算对水边线方法进行了改进,并结合潮间带实测坡度资料校正,推算遥感海岸线。选择江苏中部冲淤变化频繁、自然岸线保有率较高的扁担河口至川东港岸段开展海岸线变迁遥感监测研究。结果表明,研究区坡度主要在0.001~0.002之间,潮间带宽度由北向南越来越宽。北部扁担河口至射阳河口岸段处于冲刷环境中,大量以养殖塘围堤为主的人工岸线不断被侵蚀后退;射阳河口至四卯酉河口岸段以海岸线在自然状态下的动态变化为主,2010-2015年平均冲淤速率小于10 m/a,变化幅度较小;南部四卯酉河口至川东港岸段,自然岸线淤长明显,同时人工围垦导致岸线不断向海推进。根据监测结果,认为新洋港至斗龙港岸段应为研究区由北部侵蚀转向南部淤长的过渡带。 相似文献
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海岸线具有重要的生态功能和资源价值,在海洋保护和开发利用管理中具有举足轻重的作用。海岸线精细化、高精度、高频次监测已成为当前海岸线管理工作的新要求和新任务。以宁波市大陆海岸线为研究对象,综合运用多时相卫星遥感影像、航空遥感影像、无人机航摄影像、全野外调查等多源数据,开展宁波市2019-2021年大陆海岸线变化监测研究,对海岸线变化情况、分布情况、使用情况以及多源数据应用情况等进行分析,提出变化岸段分类标准,发现基于多源数据采集的海岸线监测具有覆盖广、准确性高、时效性强、投入成本低等特点,能够为加强海岸线保护与利用管理提供参考。 相似文献
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Tidal Flats are important examples of extensive areas of natural environment that remain relatively unaffected by man. Monitoring of tidal flats is required for a variety of purposes. Remote sensing has become an established technique for the measurement of topography over tidal flats. A further requirement is to measure topographic changes in order to measure sediment budgets. To date there have been few attempts to make quantitative estimates of morphological change over tidal flat areas. This paper illustrates the use of remote sensing to measure quantitative and qualitative changes in the tidal flats of Morecambe Bay during the relatively long period 1991–2007. An understanding of the patterns of sediment transport within the Bay is of considerable interest for coastal management and defence purposes. Tidal asymmetry is considered to be the dominant cause of morphological change in the Bay, with the higher currents associated with the flood tide being the main agency moulding the channel system. Quantitative changes were measured by comparing a Digital Elevation Model (DEM) of the intertidal zone formed using the waterline technique applied to satellite Synthetic Aperture Radar (SAR) images from 1991–1994, to a second DEM constructed from airborne laser altimetry data acquired in 2005. Qualitative changes were studied using additional SAR images acquired since 2003. A significant movement of sediment from below Mean Sea Level (MSL) to above MSL was detected by comparing the two Digital Elevation Models, though the proportion of this change that could be ascribed to seasonal effects was not clear. Between 1991 and 2004 there was a migration of the Ulverston channel of the river Leven north-east by about 5 km, followed by the development of a straighter channel to the west, leaving the previous channel decoupled from the river. This is thought to be due to independent tidal and fluvial forcing mechanisms acting on the channel. The results demonstrate the effectiveness of remote sensing for measurement of long-term morphological change in tidal flat areas. An alternative use of waterlines as partial bathymetry for assimilation into a morphodynamic model of the coastal zone is also discussed. 相似文献
9.
Mapping shoreline changes along coastal regions is critically important in monitoring continuously rising sea surface heights due to climate change and frequent severe storms. Thus, it is especially important if the region has very high tidal ranges over very gentle tidal flats, which is a very vulnerable region. Although the various remote sensing platforms can be used to map shoreline changes, the spatial and temporal resolutions are not enough to obtain it for a short time. Accordingly, in this study we introduce the newly developed low altitude Helikite remote sensing platform to achieve much better resolutions of shorelines and a bathymetry. The Helikite stands for Helium balloon and Kite, which is a kind of aerial platform that uses the advantages of both a Helium balloon and a kite. Field experiments were conducted in the Jaebu Island, off the coast of the west Korean Peninsula in January 29, 2011. In order to extract shorelines from the consecutive images taken by the low altitude Helikite remote sensing platform, active contours without edges (ACWE) is used. Edges or boundaries exist primarily on places between one type of objective and the other. Since the hydrodynamic pressure has an effect everywhere, the locations of the waterlines can be the isobath lines. We could map several waterlines, which would enable us to complete a local bathymetry map ranges from 35 to 60 cm depth. The error resulting from applying ACWE algorithm to the imagery to determine the waterline is approximately less than 1 m. Therefore, it is very unique way to obtain such high resolutions of bathymetry with high accuracy for the regions of extremely high tidal ranges for a short time. 相似文献
10.
利用海岸线的海洋遥感图像控制点(GCP)自动匹配法 总被引：5，自引：2，他引：3
研究一种利用海岸线自动确定海上地面控制点(GCP)的方法.借助边缘检测技术提取海岸线,将海岸线的点全部作为控制点的备选集合,利用相关松弛法寻找同名点,建立一种可靠判别机制来保证海岸线上GCP的正确性,通过平均法和插值法求取海上GCP的值.利用本方法可以方便地得到分布密集的GCP值,其中海上GCP值具有子像元精度.同时研究了一种新的几何变换方法,即用插值法直接求取需校正图像的几何变换坐标,随着插值密度的增加,求得海上GCP值的点就越多,最后使所有点的坐标值通过插值方法计算得到,代替二元n次方程组进行空间坐标变换,使遥感图像的几何配准误差在某种程度上达到0,利用该方法对海洋遥感资料进行几何配准,可以提高配准的精度和节省机时,为遥感资料的动态监测和数据库建设创造了有利条件. 相似文献
11.
Many ship-borne geodetic surveys at sea, such as Global Navigation Satellite System (GNSS)-based sea surface height (SSH) observation, acoustic profiling of the bottom, and others, deal with a dynamic topography which undergoes several changes during the survey campaign (e.g., changes in tide, salinity and currents). Those changes affect the measurements and may causes for some variations in the results. There are several methods for tidal variations correction, being the most dominant phenomena, such as tidal zoning, tidal constituent interpolation or ocean tidal models. In this study, we have implemented the tidal constituent interpolation method for the Israeli coastline in order to assess its quality and determine whether it is suitable for use in this particular region. This paper depicts the interpolation method, discusses some difficulties in the implementation for the Israeli coast and presents results from exemplary processing. In addition, we compare the results to those obtained using global and regional tidal models. 相似文献
12.
The exposed area of intertidal zone varies with tidal water level changes. If intercomparisons of
satellite images are adopted as a method to determine geomorphological changes of the intertidal
zone in response to accretion or erosion processes, then the e?ect of water level variations must be
evaluated. In this study, two Landsat TM images overpassing the central Jiangsu coastal waters on
2 January and 7 March 2002, respectively, were treated by the changing detection analysis using
Image Di?erencing and Post-classiˉcation Comparison. The simultaneous tide level data from four
tide gauge stations along the coast were used for displaying the spatial variations of water levels
and determining the elevations of waterlines. The results show that the spatial variations of water
levels are highly signiˉcant in the central Jiangsu coastal waters. The huge di?erences of tidal land
exposure patterns between the two imaging times are related mainly to the spatial variations of
tidal water levels, which are controlled by the di?erences in tidal phases for di?erent imaging times
and the spatial variations of water level over the study area at each imaging time. Under complex
tidal conditions, e.g., those of the central Jiangsu coastal waters, the tide-surge model should be
used to eliminate e?ectively the e?ects of water level variations on remote sensing interpretation of
geomorphological changes in the intertidal zone. 相似文献
13.
基于Sentinel-2A卫星数据面向对象的水边线提取——以如东县为例 总被引：1，自引：0，他引：1
使用基于面向对象的方法提取水边线, B分量作为阈值分割条件, Sentinel-2A数据作为提取水边线的影像,通过多尺度分割与光谱差异分割组合的方式。对如东沿海的淤泥质海岸、交通围堤海岸和养殖围堤海岸3种不同类型的海岸水边线进行提取。通过提取的水边线与影像叠加,并对受潮汐影响较小的水边线做精度验证。总体来说,提取的水边线较为准确。水边线的快速准确提取,对监测海岸带动态变化具有重要意义。 相似文献
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潮滩作为动态变化的后备土地资源,对其研究具有重要意义。文章以江苏省如东县为研究区,使用环境资源卫星(HJ1A/1B)影像为数据源,应用面向对象技术创建分类规则,实现批量半自动提取水边线,随后利用DSAS软件处理水边线集获得潮位点集,基于最外边界法实现高(低)潮位点的提取,进而获得潮滩范围,估算的如东县潮滩面积为55 182hm~2。最后利用误差矩阵进行精度验证(Kappa系数为0.945)。结果表明:该方法对于潮滩面积提取具有适用性,无论在空间域还是时间域都具有一定的推广性。 相似文献
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红树林岸外光滩高程变化是红树林可持续性发展的重要环境因素。本文以南海西北部英罗湾为研究区,利用多时相多源遥感影像提取水边线,并结合迭代的FVCOM水动力模型模拟方法,建立了2008年和2015年两个时期红树林岸外光滩数字高程模型(Digital Elevation Model, DEM)。利用两个时期的反演结果进行空间叠置分析,结果表明:2008年至2015年,湾顶光滩大部分呈现稳定-淤积状态;位于海湾中部至口门的光滩,从上部到下部整体呈现从淤积-稳定-侵蚀的趋势,其中光滩中部局部出现沟壑状侵蚀,与大型潮沟的发育和摆动有关;而光滩上部冲淤的空间差异性,主要由于红树林林区扩张形态以及人类活动的干预。 相似文献
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水边线法是潮间带地形遥感反演的重要方法。针对常规水边线方法在应用于地形多变的岸外沙洲潮间带数字高程模型（DEM）构建中出现的水边线交叉和缺乏表现潮沟微地形特征的问题,本文提出了一种增强型地形遥感构建方法:首先通过潮位排序,筛选出具有正确高程变化趋势、空间分离的水边线;然后对筛选过程中水边线位置相近的影像组按像元计算改进的归一化差值水体指数并进行均值序列合成,提取出合成海陆边界线,二者共同构建出初始的潮间带DEM;进一步利用低潮期的潮沟边界线和中线生成潮沟DEM,通过潮沟镶嵌处理,最终获得可表达滩面微地形起伏的潮滩DEM。该方法在江苏岸外辐射沙洲中部核心区域的模拟应用表明,对比4条验证剖面的平均结果,高程平均绝对误差为0.43 m,均方根误差为0.54 m,相关系数（r）为0.75,模拟高程与验证高程在剖面起伏形态变化方面具有良好的一致性,同时模拟DEM的空间破碎度小,能够反映更多的细节地形特征。该方法可为利用多源遥感数据构建考虑微地形变化的高精度潮间带地形DEM提供新的思路。 相似文献
17.
文章针对中低分辨率遥感影像难以提取海岸线中小尺度变化的实际问题,以渤海湾为例,利用2010—2020年SPOT5、GF-1/6、ZY-3等高分辨率遥感影像,采用数字海岸线分析和分形维数方法获取渤海湾海岸线位置变迁速率和复杂度变化过程;针对目前渤海湾海岸线变迁分析研究多基于中低分辨率遥感影像的问题,结合同时期的Landsat影像,分析遥感影像空间分辨率对渤海湾海岸线变迁速率和分形维数的影响。研究结果表明,遥感影像空间分辨率差异对分形维数的影响较小,但对不同类型的岸线变迁速率影响显著;渤海湾海岸线在2010—2020年的变化呈现出由剧烈过渡至相对稳定的状态,伴随着海岸线位置的变化,岸线的分形维数呈现出先上升再至平稳的趋势。相关研究成果能够为渤海湾地区海洋资源利用优化、海岸线及滩涂湿地等自然资源保护提供数据支持。 相似文献
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海岸线对于海岸带保护与管理具有重要意义。海岸线现场测绘施测周期长且在地形复杂的区域施测难度大,基于遥感影像的海岸线判绘对解译人员的要求高,难以获取严格意义的海岸线。针对上述问题,本文提出一种基于机载LiDAR与潮汐推算的自然岸线遥感提取方法:基于机载LiDAR系统获取的航空正射影像解译瞬时水边线,应用LiDAR系统提取的DEM和建立的高程系统转换模型,通过潮汐数据推算研究区域的海岸线。通过与“908专项”航空遥感调查岸线结果比对,按本文方法所提取的3种自然岸线(砂质岸线、基岩岸线和淤泥质岸线)的均方根误差分别为1.66,5.23和32.48 m。结果表明,该方法可用于砂质岸线和基岩岸线的提取,且具有无需开展现场测量工作的优势,可提高海岸线提取的效率。 相似文献
19.
基于GF-1卫星遥感影像的海岸线生态化监测与评价研究——以营口市为例 总被引：1，自引：0，他引：1
海岸线是海洋与陆地的分界线,也是重要的生态交错线。本文采用GF-1卫星遥感影像,通过监测大潮高潮时刻和小潮低潮时刻海岸水陆边界线,构建了潮间带完整性系数,以此为依据将海岸线划分为自然海岸线、具有基本生态功能的人工海岸线、具有部分生态功能的人工海岸线、具有有限生态功能的人工海岸线、具有少量生态功能的人工海岸线和无生态功能的人工海岸线。在此基础上,结合潮间带完整性系数及其毗邻海岸线长度,构建了海岸线生态化指数,用以评价区域海岸线的生态化程度。营口市海岸线以无生态功能的人工海岸线、自然海岸线和具有少量生态功能的人工海岸线为主,分别占到海岸线总长度的45.74%、18.31%和15.53%。营口市总体海岸线生态化指数为0.29,其中西城区、老边区、盖州北、鲅鱼圈区和盖州南分别为0.55、0.17、0.40、0.10和0.55。 相似文献
20.
淤泥质海岸冲淤变化大,岸滩剖面形态多样。本文首先根据多时相遥感水边线之间的潮差关系自动判断岸滩剖面形态,进而分别采用不同的函数进行剖面拟合,构建了一种剖面形态自适应的海岸线遥感推算新方法,并在江苏中部淤泥质海岸进行了实证应用。研究表明:下凹形侵蚀岸段、斜坡形平缓岸段和上凸形淤长岸段分别采用三指数衰减函数、线性函数和二阶多项式函数具有良好的剖面拟合效果,利用3条水边线数据拟合所得剖面平均坡度绝对误差分别为0.20‰、–0.17‰和0.13‰,小于剖面实测平均坡度一个数量级。利用5条水边线数据拟合进行海岸线推算时,侵蚀岸段、平缓岸段的海岸线平面位置误差分别为6.5 m和–91.96 m,与平均坡度法相比,误差减小约82.4%。进一步考虑岸滩季节性变化时,使用冬季的水边线数据推算海岸线,对侵蚀岸段和淤长岸段影响不大,但对斜坡形平缓岸段,误差减小约63.65%,因此使用冬季的水边线数据比不区分季节具有更高的海岸线推算精度。 相似文献