Digital elevation model (DEM) from the Hydrologic Derivatives for Modeling and Analysis (HDMA) database -- Greenland

This dataset contains the Digital Elevation Model (DEM) for Greenland from the Hydrologic Derivatives for Modeling and Analysis (HDMA) database. The HDMA database provides comprehensive and consistent global coverage of raster and vector topographically derived layers, including raster layers of digital elevation model (DEM) data, flow direction, flow accumulation, slope, and compound topographic index (CTI); and vector layers of streams and catchment boundaries. The coverage of the data is global (-180º, 180º, -90º, 90º) with the underlying DEM being a hybrid of three datasets: HydroSHEDS (Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales), Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010) and the Shuttle Radar Topography Mission (SRTM). For most of the globe south of 60º North, the raster resolution of the data is 3-arc-seconds, corresponding to the resolution of the SRTM. For the areas North of 60º, the resolution is 7.5-arc-seconds (the smallest resolution of the GMTED2010 dataset) except for Greenland, where the resolution is 30-arc-seconds. The streams and catchments are attributed with Pfafstetter codes, based on a hierarchical numbering system, that carry important topological information.

本数据集收录了来自水文建模与分析衍生数据库（Hydrologic Derivatives for Modeling and Analysis, HDMA）的格陵兰岛数字高程模型（Digital Elevation Model, DEM）数据。HDMA数据库提供覆盖全球的统一标准化栅格与矢量地形衍生图层，具体包含数字高程模型（DEM）、流向、汇流量、坡度及复合地形指数（Compound Topographic Index, CTI）等栅格图层，以及水系与汇水区边界矢量图层。该数据集的全球覆盖范围为(-180°，180°，-90°，90°)，其基础DEM由三类数据集融合构建：多尺度航天飞机高程衍生水文数据与地图（HydroSHEDS）、2010年全球多分辨率地形高程数据（GMTED2010）以及航天飞机雷达地形测绘任务（SRTM）数据。在北纬60°以南的绝大多数全球区域，该栅格数据的分辨率为3弧秒，与SRTM数据的分辨率保持一致；而在北纬60°以北的区域，除格陵兰岛外，分辨率为7.5弧秒（即GMTED2010数据集的最低分辨率），格陵兰岛的分辨率则为30弧秒。水系与汇水区图层附带基于层级编号体系的普发夫斯特特编码（Pfafstetter codes），该编码承载了重要的拓扑信息。