CapeCodBay_transects_rates_LTwo.shp - Digital Shoreline Analysis System version 4.3 transects and long-term linear regression shoreline change statistics without shorelines from 1970-1979 and 1994 within the Cape Cod Bay coastal region from the Cape Cod Canal in Sandwich to Long Point in Provinceto

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，当前亟需获取海岸线移动趋势与速率的相关数据，以支撑海岸线及洪泛区的管理工作。马萨诸塞州海岸带管理办公室（Massachusetts Office of Coastal Zone Management）于1989年启动海岸线变化项目（Shoreline Change Project），旨在识别沿海易受侵蚀的区域。2001年，研究人员新增1994年的海岸线数据，用于计算马萨诸塞州面向海洋岸段上、以40米为间隔的海岸线长期与短期变化速率。 美国地质调查局（U.S. Geological Survey, USGS）海岸与海洋地质项目联合马萨诸塞州海岸带管理办公室，依托《马萨诸塞州海岸线变化制图与分析项目2013年更新版》，完成了马萨诸塞州开阔岸段可靠历史海岸线数据的汇编工作。该团队共完成马萨诸塞州约1800公里滨海海岸线的两项测绘：(1) 基于2008/2009年彩色航空正射影像进行岸线勾绘；(2) 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）数据集中提取岸线信息。研究团队将新绘制的海岸线数据与马萨诸塞州海岸带管理办公室及USGS已有的历史海岸线数据集进行整合，借助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。