Land-Cover Data Derived from Landsat Satellite Imagery, Assateague Island to Metompkin Island, Maryland and Virginia, 1985 and 2015

This U.S. Geological Survey (USGS) data release includes geospatial datasets that were created to analyze wetland changes along the Virginia and Maryland Atlantic coasts between 1984 and 2015. Wetland change was determined by assessing two metrics: wetland persistence and land-cover switching. Because seasonal water levels, beach width, and vegetation differences can affect change analyses, only images acquired during the spring (March, April, and May) were included in the wetland-change metrics (N=10).
USGS Data Series 968 (Bernier and others, 2015) presented data that were derived from Landsat 5 and Landsat 8 imagery from 1984 to 2014, including wetland and terrestrial habitat extents; open-ocean, back-barrier, and estuarine mainland shoreline positions; and sand-line positions along the estuarine mainland and barrier shorelines from Assateague Island, Maryland to Metompkin Island, Virginia. As part of the wetland-change analyses, two additional satellite images (17-April-1985 and 05-May-2015) were processed and classified using the methods described by Bernier and others (2015) to provide a more complete time series dataset. One additional image (26-April-1994) was reprocessed to correct a classification error that was identified when comparing wetland and total analysis extents among all images.

美国地质调查局（U.S. Geological Survey, USGS）本次发布的数据包含一组地理空间数据集，用于分析1984年至2015年间弗吉尼亚州与马里兰州大西洋沿岸的湿地变化情况。本次湿地变化通过两项指标判定：湿地持久性与土地覆盖转换。由于季节性水位、滩涂宽度与植被差异均会对变化分析产生干扰，因此本次湿地变化指标分析仅纳入春季（3月、4月、5月）获取的影像（共10景）。

美国地质调查局数据系列968（Bernier等人，2015年）所发布的数据源自1984年至2014年的Landsat 5与Landsat 8影像，数据内容涵盖湿地与陆地生境范围、公海-后滨及河口大陆岸线位置，以及从马里兰州阿萨蒂格岛到弗吉尼亚州梅托姆普金岛的河口大陆岸线与障壁岸线沿线的沙线位置。作为湿地变化分析的补充环节，本次研究采用Bernier等人（2015年）提出的方法，对另外两景卫星影像（1985年4月17日、2015年5月5日）进行了处理与分类，以构建更为完整的时间序列数据集。此外，为修正所有影像在湿地与总分析范围对比过程中发现的分类误差，研究人员还对1994年4月26日的一景影像进行了重新处理。