CapeCodBay_transects_rates_STepr.shp - Digital Shoreline Analysis System version 4.3 transects and short-term (1970-2009) end point rate shoreline change statistics within the Cape Cod Bay coastal region from the Cape Cod Canal in Sandwich to Long Point in Provincetown

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 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).

鉴于沿海人口持续增长，海岸侵蚀威胁日益加剧，当前亟需岸线变化趋势与速率的相关数据，以支撑岸线与洪泛区管理工作。马萨诸塞州海岸带管理办公室（Massachusetts Office of Coastal Zone Management）于1989年启动岸线变化项目，旨在识别沿海易侵蚀区域。2001年，该项目新增1994年岸线数据，用于计算马萨诸塞州沿海面向大洋区段内每40米间隔的长、短期岸线变化速率。

美国地质调查局（U.S. Geological Survey, USGS）海岸与海洋地质项目组与马萨诸塞州海岸带管理办公室合作，依托《2013年马萨诸塞州岸线变化制图与分析项目更新》，完成了马萨诸塞州沿海开阔区段可靠历史岸线数据的汇编工作。该数据集包含两条马萨诸塞州沿海岸线（总长约1800千米）：其一通过2008/2009年彩色航空正射影像图勾绘而成，其二则从美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）海洋服务局海岸服务中心获取的2007年地形激光雷达（LIDAR）数据集中提取得到。新生成的岸线数据与马萨诸塞州海岸带管理办公室及USGS现存的历史岸线数据进行整合，以借助最新版数字岸线分析系统（Digital Shoreline Analysis System, DSAS）计算长、短期岸线变化速率。