EEA marine assessment grid, Jan. 2017

This metadata refers to the EEA marine assessment grid, to which all data and assessment results have been spatially mapped in order to ensure that data can be compared in a uniform way across the European regional seas. The marine assessment grid is based on the EEA reference grid system. The EEA reference grid is based on ERTS89 Lambert Azimuthal Equal Area projection with parameters: latitude of origin 52° N, longitude of origin 10° E, false northing 3 210 000.0 m, false easting 4 321 000.0 m. All grid cells are named with a unique identifier containing information on grid cell size and the distance from origin in meters (easting and northing). An important attribute of the EEA reference grid system is that by using an equal area projection all grid cells are having the same area for the same grid size. In this marine assessment grid, two grid sizes are used: * 100 x 100 km in offshore areas (> 20 km from the coastline) * 20 x 20 km in coastal areas (<= 20 km from the coastline) The grid sizes were choosen after an evaluation of data availability versus the need for sufficient detail in the resulting assessment. The resulting assessment grid is a combination of two grid sizes using the EEA reference grid system. The overall area of interest used in the grid is based on the marine regions and subregions under the Marine Strategy Framework Directive (MSFD). Additionally, Norwegian (Barent Sea and Norwegian Sea) and Icelandic waters (’Iceland Sea’) have been added (see Surrounding seas of Europe). Note that, within the North East Atlantic region, only the subregions within EEZ boundaries (~200 nm) have been included.本元数据对应欧洲环境署（European Environment Agency, EEA）海洋评估网格，所有数据与评估结果均已完成空间配准至该网格，以确保欧洲各区域海域内的数据可采用统一标准进行比对。 本海洋评估网格基于EEA参考网格系统构建。EEA参考网格采用ERTS89兰伯特方位等面积投影（ERTS89 Lambert Azimuthal Equal Area），其投影参数为：原点纬度52°N，原点经度10°E，北伪偏移3210000.0米，东伪偏移4321000.0米。所有网格单元均采用唯一标识符命名，该标识符包含网格单元尺寸以及距原点的东向、北向距离（单位：米）相关信息。EEA参考网格系统的一项重要特性为：通过等面积投影，相同尺寸的所有网格单元拥有完全一致的面积。 本海洋评估网格采用两种网格尺寸： - 近海区域（距海岸线＞20km）：100×100km - 近岸区域（距海岸线≤20km）：20×20km 上述网格尺寸的选取，经过了对数据可得性与评估结果所需细节程度的综合权衡。最终的评估网格基于EEA参考网格系统，由两种尺寸的网格单元组合而成。 本网格所覆盖的关注海域范围，基于《海洋战略框架指令（Marine Strategy Framework Directive, MSFD）》划定的海洋区域与子区域。此外，还补充纳入了挪威海域（巴伦支海与挪威海）以及冰岛海域（冰岛海）相关范围（详见《欧洲周边海域》文档）。需注意的是，在东北大西洋区域内，仅纳入了专属经济区（Exclusive Economic Zone, EEZ）界线（约200海里）以内的子区域。