California State Waters Map Series--Drakes Bay Web Services

In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within California’s State Waters. The program supports a large number of coastal-zone- and ocean-management issues, including the California Marine Life Protection Act (MLPA) (California Department of Fish and Wildlife, 2008), which requires information about the distribution of ecosystems as part of the design and proposal process for the establishment of Marine Protected Areas. A focus of CSMP is to map California’s State Waters with consistent methods at a consistent scale. The CSMP approach is to create highly detailed seafloor maps through collection, integration, interpretation, and visualization of swath sonar data (the undersea equivalent of satellite remote-sensing data in terrestrial mapping), acoustic backscatter, seafloor video, seafloor photography, high-resolution seismic-reflection profiles, and bottom-sediment sampling data. The map products display seafloor morphology and character, identify potential marine benthic habitats, and illustrate both the surficial seafloor geology and shallow (to about 100 m) subsurface geology. It is emphasized that the more interpretive habitat and geology data rely on the integration of multiple, new high-resolution datasets and that mapping at small scales would not be possible without such data. This approach and CSMP planning is based in part on recommendations of the Marine Mapping Planning Workshop (Kvitek and others, 2006), attended by coastal and marine managers and scientists from around the state. That workshop established geographic priorities for a coastal mapping project and identified the need for coverage of “lands” from the shore strand line (defined as Mean Higher High Water; MHHW) out to the 3-nautical-mile (5.6-km) limit of California’s State Waters. Unfortunately, surveying the zone from MHHW out to 10-m water depth is not consistently possible using ship-based surveying methods, owing to sea state (for example, waves, wind, or currents), kelp coverage, and shallow rock outcrops. Accordingly, some of the data presented in this series commonly do not cover the zone from the shore out to 10-m depth. This data is part of a series of online U.S. Geological Survey (USGS) publications, each of which includes several map sheets, some explanatory text, and a descriptive pamphlet. Each map sheet is published as a PDF file. Geographic information system (GIS) files that contain both ESRI ArcGIS raster grids (for example, bathymetry, seafloor character) and geotiffs (for example, shaded relief) are also included for each publication. For those who do not own the full suite of ESRI GIS and mapping software, the data can be read using ESRI ArcReader, a free viewer that is available at http://www.esri.com/software/arcgis/arcreader/index.html (last accessed September 20, 2013). The California Seafloor Mapping Program is a collaborative venture between numerous different federal and state agencies, academia, and the private sector. CSMP partners include the California Coastal Conservancy, the California Ocean Protection Council, the California Department of Fish and Wildlife, the California Geological Survey, California State University at Monterey Bay’s Seafloor Mapping Lab, Moss Landing Marine Laboratories Center for Habitat Studies, Fugro Pelagos, Pacific Gas and Electric Company, National Oceanic and Atmospheric Administration (NOAA, including National Ocean Service–Office of Coast Surveys, National Marine Sanctuaries, and National Marine Fisheries Service), U.S. Army Corps of Engineers, the Bureau of Ocean Energy Management, the National Park Service, and the U.S. Geological Survey. These web services for the Drakes Bay map area includes data layers that are associated to GIS and map sheets available from the USGS CSMP web page at https://walrus.wr.usgs.gov/mapping/csmp/index.html. Each published CSMP map area includes a data catalog of geographic information system (GIS) files; map sheets that contain explanatory text; and an associated descriptive pamphlet. This web service represents the available data layers for this map area. Data was combined from different sonar surveys to generate a comprehensive high-resolution bathymetry and acoustic-backscatter coverage of the map area. These data reveal a range of physiographic including exposed bedrock outcrops, large fields of sand waves, as well as many human impacts on the seafloor. To validate geological and biological interpretations of the sonar data, the U.S. Geological Survey towed a camera sled over specific offshore locations, collecting both video and photographic imagery; these “ground-truth” surveying data are available from the CSMP Video and Photograph Portal at http://dx.doi.org/10.5066/F7J1015K. The “seafloor character” data layer shows classifications of the seafloor on the basis of depth, slope, rugosity (ruggedness), and backscatter intensity and which is further informed by the ground-truth-survey imagery. The “potential habitats” polygons are delineated on the basis of substrate type, geomorphology, seafloor process, or other attributes that may provide a habitat for a specific species or assemblage of organisms. Representative seismic-reflection profile data from the map area is also include and provides information on the subsurface stratigraphy and structure of the map area. The distribution and thickness of young sediment (deposited over the past about 21,000 years, during the most recent sea-level rise) is interpreted on the basis of the seismic-reflection data. The geologic polygons merge onshore geologic mapping (compiled from existing maps by the California Geological Survey) and new offshore geologic mapping that is based on integration of high-resolution bathymetry and backscatter imagery seafloor-sediment and rock samplesdigital camera and video imagery, and high-resolution seismic-reflection profiles. The information provided by the map sheets, pamphlet, and data catalog has a broad range of applications. High-resolution bathymetry, acoustic backscatter, ground-truth-surveying imagery, and habitat mapping all contribute to habitat characterization and ecosystem-based management by providing essential data for delineation of marine protected areas and ecosystem restoration. Many of the maps provide high-resolution baselines that will be critical for monitoring environmental change associated with climate change, coastal development, or other forcings. High-resolution bathymetry is a critical component for modeling coastal flooding caused by storms and tsunamis, as well as inundation associated with longer term sea-level rise. Seismic-reflection and bathymetric data help characterize earthquake and tsunami sources, critical for natural-hazard assessments of coastal zones. Information on sediment distribution and thickness is essential to the understanding of local and regional sediment transport, as well as the development of regional sediment-management plans. In addition, siting of any new offshore infrastructure (for example, pipelines, cables, or renewable-energy facilities) will depend on high-resolution mapping. Finally, this mapping will both stimulate and enable new scientific research and also raise public awareness of, and education about, coastal environments and issues. Web services were created using an ArcGIS service definition file. The ArcGIS REST service and OGC WMS service include all Drakes Bay map area data layers. Data layers are symbolized as shown on the associated map sheets.2007年，加利福尼亚海洋保护委员会（California Ocean Protection Council）启动了加利福尼亚海底测绘计划（California Seafloor Mapping Program, CSMP），旨在为加利福尼亚州管辖海域绘制一套涵盖高分辨率水深地形、海洋底栖生境与地质特征的综合海底地图。该计划支撑了大量海岸带与海洋管理相关议题，其中包括《加利福尼亚海洋生物保护法》（California Marine Life Protection Act, MLPA）（加利福尼亚鱼类与野生动物部，2008年）——该法案要求在海洋保护区（Marine Protected Areas, MPAs）的设计与申报流程中，提供生态系统分布相关信息作为支撑。CSMP的核心目标之一，是以统一方法与统一比例尺完成加利福尼亚州管辖海域的海底测绘。 CSMP的实施路径为：通过采集、整合、解译与可视化条带声呐数据（swath sonar data，陆地测绘中卫星遥感数据的海底等效物）、声学后向散射（acoustic backscatter）数据、海底视频、海底摄影、高分辨率地震反射剖面（high-resolution seismic-reflection profiles）以及海底沉积物采样数据，生成高精度海底地图。其地图产品可展示海底地貌形态与特征，识别潜在海洋底栖生境，并同时呈现表层海底地质与浅层（约100米以浅）地下地质情况。需要强调的是，更具解译价值的生境与地质数据依赖于多组新型高分辨率数据集的整合，若缺乏此类数据，小比例尺测绘将无法实现。 该实施路径与CSMP的规划在一定程度上基于海洋测绘规划研讨会（Kvitek等，2006年）提出的建议，该研讨会吸引了全州范围内的海岸与海洋管理者及科研人员参与。研讨会确立了海岸测绘项目的地理优先级，并明确了需覆盖“岸线”（定义为平均高高潮位，Mean Higher High Water, MHHW）至加利福尼亚州管辖海域3海里（nautical-mile，约5.6公里）界限范围的需求。遗憾的是，受海况（如海浪、风力或洋流）、海藻覆盖以及浅海岩石露头的限制，利用船载勘测方法无法始终完成从MHHW至10米水深区域的测绘。因此，本系列数据中的部分数据集通常无法覆盖从岸线至10米水深的区域。 本数据集属于美国地质调查局（U.S. Geological Survey, USGS）在线出版物系列的一部分，该系列的每一本出版物均包含多幅地图图幅、若干说明性文字与一份介绍性手册。每幅地图图幅均以便携式文档格式（PDF）发布。此外，每份出版物还附带地理信息系统（Geographic Information System, GIS）文件，其中包含ESRI ArcGIS栅格数据集（ESRI ArcGIS raster grids，如水深地形、海底特征数据）与地理标记图像文件格式（GeoTIFF，如阴影晕渲图）文件。对于未配备全套ESRI GIS与测绘软件的用户，可通过ESRI ArcReader（一款免费查看器，下载地址为http://www.esri.com/software/arcgis/arcreader/index.html，最后访问时间为2013年9月20日）读取此类数据。 加利福尼亚海底测绘计划是一项由众多联邦与州级机构、学术界及私营部门共同参与的合作项目。CSMP的合作方包括：加利福尼亚海岸保护委员会、加利福尼亚海洋保护委员会、加利福尼亚鱼类与野生动物部、加利福尼亚地质调查局、蒙特雷湾加利福尼亚州立大学海底测绘实验室、莫斯兰丁海洋实验室生境研究中心、Fugro Pelagos公司、太平洋天然气和电力公司、美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA，包含国家海洋服务局海岸测绘办公室、国家海洋保护区办公室与国家海洋渔业局）、美国陆军工程兵团、海洋能源管理局、美国国家公园管理局以及美国地质调查局。 德雷克湾地图区域的网络服务包含与美国地质调查局CSMP网页（https://walrus.wr.usgs.gov/mapping/csmp/index.html）上可获取的GIS与地图图幅相关联的数据图层。 每幅公开发布的CSMP地图区域均包含地理信息系统（GIS）文件数据目录、带说明文字的地图图幅以及配套介绍手册。本网络服务即代表该地图区域的可用数据图层。研究人员通过整合不同声呐勘测数据，生成了该地图区域内一套完整的高分辨率水深地形与声学后向散射覆盖数据。这些数据揭示了丰富的地貌特征，包括裸露的基岩露头、大型沙波群，以及诸多人类活动对海底造成的影响。为验证声呐数据的地质与生物学解译结果，美国地质调查局在特定近海区域拖曳摄像雪橇，采集了视频与摄影影像；此类“地面实况”（ground-truth）勘测数据可通过CSMP视频与摄影门户获取（http://dx.doi.org/10.5066/F7J1015K）。“海底特征”（seafloor character）数据图层基于水深、坡度、粗糙度（rugosity，崎岖度）与后向散射强度对海底进行分类，并通过地面实况勘测影像进一步优化。“潜在生境”（potential habitats）多边形则基于底质类型、地貌形态、海底过程或其他可为特定物种或生物群落提供栖息环境的属性进行划定。本地图区域还附带代表性地震反射剖面数据，可用于揭示研究区的地下地层与构造。基于地震反射数据，研究人员解译了年轻沉积物（形成于最近一次海平面上升时期，即约21000年前）的分布与厚度。地质多边形整合了陆上地质测绘成果（由加利福尼亚地质调查局基于现有地图汇编）与基于高分辨率水深地形、后向散射影像、海底沉积物与岩石样本、数码相机与视频影像以及高分辨率地震反射剖面整合得到的新型海底地质测绘成果。 地图图幅、介绍手册与数据目录所提供的信息应用场景广泛。高分辨率水深地形、声学后向散射、地面实况勘测影像与生境测绘数据均可为生境特征描述与基于生态系统的管理提供支撑，为海洋保护区划定与生态系统修复提供关键数据。诸多地图提供了高分辨率基线数据，这对于监测气候变化、海岸开发或其他驱动因素引发的环境变化至关重要。高分辨率水深地形是模拟风暴与海啸引发的海岸洪水，以及长期海平面上升导致的淹没情况的关键组成部分。地震反射与水深地形数据有助于刻画地震与海啸震源特征，为海岸带自然灾害评估提供关键支撑。沉积物分布与厚度信息对于理解局地与区域沉积物运移过程、制定区域沉积物管理计划均不可或缺。此外，任何新型离岸基础设施（如管道、电缆或可再生能源设施）的选址都将依赖高分辨率测绘成果。最后，此类测绘工作既将推动并支撑全新的科学研究，也将提升公众对海岸环境与相关议题的认知与了解。 本网络服务基于ArcGIS服务定义文件创建。ArcGIS REST服务与OGC WMS服务包含德雷克湾地图区域的所有数据图层。数据图层的符号化方式与配套地图图幅中展示的一致。