Hydro1k North American - Flow Accumulation

HYDRO1k is a geographic database developed to provide
comprehensive and consistent global coverage of topographically
derived data sets, including streams, drainage basins and
ancillary layers derived from the USGS' 30 arc-second digital
elevation model of the world (GTOPO30). HYDRO1k provides a suite
of geo-referenced data sets, both raster and vector, which will
be of value for all users who need to organize, evaluate, or
process hydrologic information on a continental scale.
Developed at the U.S. Geological Survey's EROS Data Center , the
HYDRO1k project's goal is to provide to users, on a continent by
continent basis, hydrologically correct DEMs along with
ancillary data sets for use in continental and regional scale
modeling and analyses.

HYDRO1k是一款地理数据库，旨在提供覆盖全球的统一一致的地形衍生数据集，涵盖水系、流域以及由美国地质调查局（USGS）全球30弧秒数字高程模型（GTOPO30）衍生的辅助图层。HYDRO1k提供一套地理参考数据集，包含栅格与矢量两种格式，可为所有需要在大陆尺度上组织、评估或处理水文信息的用户提供支持。该项目由美国地质调查局地球资源数据中心（EROS Data Center）开发，其目标是按大洲为用户提供经过水文校正的数字高程模型（Digital Elevation Model，DEM），以及适用于大陆与区域尺度建模与分析的辅助数据集。