An ecotope map of the trilateral Wadden Sea

These data present the first digital, publicly available, ecotope map of the trilateral Wadden Sea covering the Netherlands, Germany and Denmark. This ecotope map, representative for the time period 2008-2012, was developed on the basis of bathymetry, salinity, flow velocity, exposure time, sediment composition, hard substrates and salt marshes. Ecotopes are discrete classes of the physical environment based on the distributions of communities in an ecosystem. An ecotope map can give a first–order estimate of the potential spatial distribution of species and communities. The use of a single, consistent and well-defined ecotope system makes it possible to compare the proportions of the different ecotopes and compare properties of the tidal basins over the entire trilateral Wadden Sea.

This ecotope map of the trilateral Wadden Sea area followed the ecotope system for coastal waters ZES.1 typology that was developed in the Netherlands. This ecotope system is based on the notion that local physical environmental factors and processes are main determinants of communities. The main physical environmental factors and processes in the ZES.1 system were mean and variability of salinity, substratum type, mean water depth, and hydrodynamics. Class boundaries were used to classify the continuous variables in order to define the ecotopes. The ZES.1 ecotype system hierarchically arranges the ecotope variables on the basis of the dominance of the physical environmental factors and processes in determining community composition.

CORRIGENDUM. In version 1 of June 2019 an error has been made. The class boundary between shallow sublittoral and low intertidal was not set to 4% mean exposure but to 0.001%. This resulted in a too low cover of sublitoral areas. In Version 2 this is corrected. The data file is a zipped file "EctpWZ3L_gpkg.zip" containing a GeoPackage, holding the geographical data (polygons etc.):
i. EcotopeWS3_mp = polygon geodata of ecotope map
ii. bivbeds_focc = geodata for eco-element bivalve beds (polygon)
iii. eelgrass_presence = geodata for eco-element seagrass aka eelgrass presence (polygon)
iv. EcotopeWS3CodeInterpretation, table explaining how fields in ecotope map should be interpreted
v. ZESsmpleCode2Legend, table expanding ZESsimple from code to full legend text.
and includes:
2) a set of QML-files (symbology definition files for QGIS),
3) a set of SLD-files (symbology layer definition files for GeoServer),
4) three PNG-files to provide the different textures/patterns used in the symbolising the sediment types.

本数据集呈现了覆盖荷兰、德国和丹麦的三边瓦登海首份数字化公开生态单元（ecotope）地图。该生态单元地图代表2008-2012年期间的状况，基于水深测量数据、盐度、流速、暴露时间、沉积物组成、硬质基底及盐沼开发而成。生态单元是基于生态系统中群落分布划分的物理环境离散类别，其地图可对物种及群落的潜在空间分布进行一阶估计。采用统一、一致且定义明确的生态单元系统，可对整个三边瓦登海不同生态单元的比例及潮盆属性进行比较。

三边瓦登海区域的这份生态单元地图遵循荷兰开发的沿海水域生态单元系统ZES.1类型学。该系统基于以下理念：局部物理环境因子及过程是群落的主要决定因素。ZES.1系统中的核心物理环境因子及过程包括盐度均值与变异性、基底类型、平均水深及水动力学。通过类边界对连续变量分类，以界定生态单元；ZES.1生态类型系统还根据物理环境因子及过程在决定群落组成中的主导地位，对生态单元变量进行分层排列。

勘误表：2019年6月版本1中存在一处错误——浅潮下带与低潮间带的类边界未设置为平均暴露率4%，而是错误设为0.001%，导致潮下带区域覆盖率过低。版本2已修正此问题。

数据文件为压缩包“EctpWZ3L_gpkg.zip”，内含一个地理信息包（GeoPackage），包含以下地理数据（多边形等）：
i. EcotopeWS3_mp = 生态单元地图的多边形地理数据
ii. bivbeds_focc = 生态要素双壳类床的地理数据（多边形）
iii. eelgrass_presence = 生态要素海草（又称鳗草）分布的地理数据（多边形）
iv. EcotopeWS3CodeInterpretation：解释生态单元地图字段含义的表格
v. ZESsmpleCode2Legend：将ZESsimple代码扩展为完整图例文本的表格

此外还包含：
2) 一组QML文件（QGIS的符号定义文件）
3) 一组SLD文件（GeoServer的符号层定义文件）
4) 三个PNG文件：提供沉积物类型符号化所用的不同纹理/图案