50-Meter Digital Elevation Model of Coastal Bathymetry Collected in 2011 from the Chandeleur Islands, Louisiana (U.S. Geological Survey Field Activity Numbers 11BIM01 and 11BIM02)

As part of the Barrier Island Evolution Research Project, scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center conducted nearshore geophysical surveys off the northern Chandeleur Islands, Louisiana, in June of 2011. The overall objectives of the study are to better understand barrier-island geomorphic evolution, particularly storm-related depositional and erosional processes that shape the islands over annual to interannual timescales (1-5 years). Collection of geophysical data will allow us to identify relationships between the geologic history of the island and its present day morphology and sediment distribution. This mapping effort was the first in a series of three planned surveys in this area. High resolution geophysical data collected in each of three consecutive years along this rapidly changing barrier-island system will provide a unique time-series dataset that will significantly further the analyses and geomorphological interpretations of this and other coastal systems, improving our understanding of coastal response and evolution over short time scales (1-5 years).
This report serves as an archive of processed interferometric swath and single-beam bathymetry data that were collected during two cruises (USGS Field Activity Numbers 11BIM01 and 11BIM02) along the northern portion of the Chandeleur Islands, Breton National Wildlife Refuge, Louisiana, in June of 2011. Geographic information system data products include a 50 m-cell-size interpolated bathymetry grid surface, trackline maps, and point data files. Additional files include error analysis maps, Field Activity Collection System logs, and formal Federal Geographic Data Committee metadata.

作为障壁岛演化研究项目（Barrier Island Evolution Research Project）的一部分，美国地质调查局（U.S. Geological Survey，简称USGS）圣彼得堡海岸与海洋科学中心的科研人员于2011年6月在路易斯安那州尚德利尔群岛北部近岸海域开展了近岸地球物理勘测工作。本研究的总体目标是深化对障壁岛地貌演化的认知，特别是明晰在年际至跨年际时间尺度（1~5年）上塑造群岛的风暴相关沉积与侵蚀过程。地球物理数据的采集将助力我们厘清群岛地质历史与当前地貌及沉积物分布之间的关联。本次测绘工作是该区域三项规划勘测的首项。后续将连续三年在这一快速变化的障壁岛系统中开展勘测，所获取的高分辨率地球物理数据将形成独特的时间序列数据集，可为该区域及其他海岸系统的分析与地貌学解读提供重要支撑，进而增进我们对短时间尺度（1~5年）下海岸响应与演化过程的认知。

本报告作为经处理的干涉条带测深与单波束测深数据的存档资料，涵盖了2011年6月在路易斯安那州布雷顿国家野生动物保护区尚德利尔群岛北部海域开展的两次科考航次（USGS野外活动编号：11BIM01与11BIM02）所采集的数据。地理信息系统数据产品包含50米格网分辨率的插值测深网格曲面、测线地图以及点数据文件。其余附件文件包括误差分析地图、野外活动采集系统日志以及正式的联邦地理数据委员会（Federal Geographic Data Committee，简称FGDC）元数据。