ElizabethIslands_shorelines.shp - Shorelines used to calculate shoreline change statistics from the Elizabeth Islands coastal region of Massachusetts from Nonamesset Island southwest of Woods Hole to Cuttyhunk Island north of Martha's Vineyard.

Due to continued coastal population growth and increased threats of erosion, current data on trends and rates of shoreline movement are required to inform shoreline and floodplain management. The Massachusetts Office of Coastal Zone Management launched the Shoreline Change Project in 1989 to identify erosion-prone areas of the coast. In 2001, a 1994 shoreline was added to calculate both long- and short-term shoreline change rates at 40-meter intervals along ocean-facing sections of the Massachusetts coast. The Coastal and Marine Geology Program of the U.S. Geological Survey (USGS) in cooperation with the Massachusetts Office of Coastal Zone Management, has compiled reliable historical shoreline data along open-facing sections of the Massachusetts coast under the Massachusetts Shoreline Change Mapping and Analysis Project 2013 Update. Two oceanfront shorelines for Massachusetts (approximately 1,800 km) were (1) delineated using 2008/09 color aerial orthoimagery, and (2) extracted from topographic LIDAR datasets (2007) obtained from NOAA's Ocean Service, Coastal Services Center. The new shorelines were integrated with existing Massachusetts Office of Coastal Zone Management (MA CZM) and USGS historical shoreline data in order to compute long- and short-term rates using the latest version of the Digital Shoreline Analysis System (DSAS).由于沿海人口持续增长、海岸侵蚀威胁日益加剧，当前亟需获取海岸线移动趋势与速率的相关数据，以辅助海岸线及洪泛区的管理工作。1989年，马萨诸塞州沿海地带管理办公室（Massachusetts Office of Coastal Zone Management）启动海岸线变化项目，旨在识别海岸易侵蚀区域。2001年，项目组补充纳入1994年的海岸线数据，用于沿马萨诸塞州海岸面向海洋的区段以40米为间隔，测算海岸线的长期与短期变化速率。 美国地质调查局（U.S. Geological Survey, USGS）沿海与海洋地质项目组联合马萨诸塞州沿海地带管理办公室（Massachusetts Office of Coastal Zone Management），依托《2013年更新版马萨诸塞州海岸线变化制图与分析项目》，沿马萨诸塞州海岸面向开阔海域的区段，汇编了可靠的历史海岸线数据集。本次共生成两条总长约1800千米的马萨诸塞州滨海海岸线：其一通过2008/2009年彩色航空正射影像勾勒划定，其二则从美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）海洋服务中心沿海服务部获取的2007年地形激光雷达（LIDAR）数据集中提取得到。研究人员将上述新海岸线数据与马萨诸塞州沿海地带管理办公室（MA CZM）及美国地质调查局（USGS）现存的历史海岸线数据集进行整合，依托最新版数字海岸线分析系统（Digital Shoreline Analysis System, DSAS）计算海岸线的长期与短期变化速率。