Transect based analysis versus area based analysis to quantify shoreline displacement: spatial resolution issues
Transect based analysis versus area based analysis to quantify shoreline displacement: spatial resolution issues
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基于横断面的分析与基于区域的分析来量化海岸线位移：空间分辨率问题
DOI：
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发表时间：
2016
影响因子：
3
通讯作者：
E. Pranzini
中科院分区：
文献类型：
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作者：
G. Anfuso;D. Bowman;C. Danese;E. Pranzini
实地调查、航空照片和卫星图像是分析海岸线位置最常用的数据来源，并通过基于面积的分析(ABA)或基于样带的分析(TBA)方法进行了进一步的比较。前者是通过计算确定的海岸段的平均岸线位移，即用海滩面积变化量除以段长；后者是基于沿横断面设定点的每条海岸线之间的距离的测量。本研究借助地理信息系统工具，通过计算托斯卡纳海岸(意大利)两段海滩上记录的海岸线位移，比较了ABA和TBA方法：Punta Ala海滩是没有海岸保护结构的线性海岸，FolLonica海滩由于存在丁坝和分离的防波堤而是不规则的。调查是使用RTK模式的全球差分定位系统(DGPS)进行的。对于每个站点，分析了4800米长的海岸段，并将其划分为96个50米长的扇区，使用ABA和TBA方法计算了它们的变化。行业被逐步加入，长度分别为100、200、400和800米，以检查这如何影响结果。ABA和TBA的结果在两个调查地点的横断面距离和高达100米的扇区长度方面高度相关。如果考虑更长的断面，这两种方法在平坦的海岸线上(即在蓬塔阿拉邦)仍然产生良好的相关性数据，但在不规则的海岸线上(即在福洛尼察)相关性显著降低。
Field surveys, aerial photographs, and satellite images are the most commonly employed sources of data to analyze shoreline position, which are further compared by area based analysis (ABA) or transect based analysis (TBA) methods. The former is performed by computing the mean shoreline displacement for the identified coastal segments, i.e., dividing the beach area variation by the segment length; the latter is based on the measurement of the distance between each shoreline at set points along transects. The present study compares, by means of GIS tools, the ABA and TBA methods by computing shoreline displacements recorded on two stretches of the Tuscany coast (Italy): the beaches of Punta Ala, a linear coast without shore protection structures, and the one at Follonica, which is irregular due to the presence of groins and detached breakwaters. Surveys were carried out using a differential global positioning system (DGPS) in RTK mode. For each site, a 4800-m-long coastal segment was analyzed and divided into ninety-six 50-m-long sectors for which changes were computed using both the ABA and TBA methods. Sectors were progressively joined to have a length of 100, 200, 400, and 800 m to examine how this influenced results. ABA and TBA results are highly correlated for transect distance and sector length up to 100 m at both investigated locations. If longer transects are considered, the two methods still produce good correlated data on the smooth shoreline (i.e. at Punta Ala), but correlation became significantly lower on the irregular shoreline (i.e., at Follonica).