Ephemeral stream water contributions to United States drainage networks

Results from our CONUS ephemeral stream modeling study. Included in this release is a set of csv files for each CONUS drainage basin (USGS HUC level 4 basins). These lookup tables can be joined to NHD-HR hydrography (https://www.usgs.gov/national-hydrography/nhdplus-high-resolution). CSV columns are as follows: NHDPlusID: NHD-HR reach ID. Use this to join to hydrography shapefiles. perenniality: Result of our ephemeral classification model (see paper for methods). percQEph_reach: Main model result. See equation S1 in paper. Some notes: Note that continental-scale models prioritize capturing broad patterns across large domains, so we caution against over-interpreting results for individual river reaches. Great Lakes are not included, though the model does route through the lakes for topological consistency. Foreign streams are recast as 'non-ephemeral' to be copacetic with figures in the paper. See paper for more details. Some reaches present in the NHD-HR are not included in our results for a variety of reasons. See paper for details.本数据集来源于我们针对美国本土（CONUS，Continental United States）开展的暂时性溪流建模研究。本次发布的数据集包含一组CSV文件，每个文件对应一个美国本土流域，即美国地质调查局（USGS）四级水文单元（HUC level 4）流域。这些查找表可与NHD-HR水文数据集（NHDPlus High Resolution，访问链接：https://www.usgs.gov/national-hydrography/nhdplus-high-resolution）进行关联匹配。CSV文件的列字段说明如下： NHDPlusID：NHD-HR河段的唯一标识，可用于关联水文矢量Shapefile文件。 perenniality：本研究暂时性溪流分类模型的输出结果，具体研究方法详见论文。 percQEph_reach：本模型的核心输出结果，具体计算公式详见论文补充公式S1。 几点补充说明： 1. 大陆尺度流域建模的核心目标是刻画大空间范围下的宏观分布规律，因此请勿过度解读单个河段的建模结果。 2. 尽管模型为维持拓扑一致性会对五大湖区域进行径流路径模拟，但本次发布未包含五大湖相关的建模结果。 3. 为与论文中的图表保持一致，境外溪流被统一归类为“非暂时性溪流”，更多相关细节请参阅论文。 4. 受多种因素影响，NHD-HR数据集中的部分河段未被纳入本次研究的结果中，具体原因详见论文。