VT Data - VT Hydrography Dataset - cartographic extract lines

(Link to Metadata) VHDCARTO is a simplified version of the local resolution Vermont Hydrography Dataset (VHD) that has been enriched with stream perenniality, e.g., "intermittent" vs. "perennial", as well as, Strahler stream order attribution for the single linear feature class only. The primary means of accessing this information cartographically is via the FCODE and STREAM_ORDER fields, respectively. See the Entity and Attribution Information section for details. NOTE! Perenniality data does not exist for stream reaches contained within, or intersected by, Essex or Caledonia counties, thus the FCODE "46000" in these areas. The absence of Soil SUrvey GeOgraphic (SSURGO) database information in these areas precluded the computation of perenniality. These areas will be processed at some future date. For information on the FCODE symbol for attribution or analysis see the following document https://www.usgs.gov/national-hydrography/national-hydrography-dataset (NHDFlowline). A two dimensional feature class for lakes, ponds and larger streams is also included in VHDCARTO. Both layers are derived from the latest National Hydrography Dataset (NHD) data. The NHD is a feature-based database that interconnects and uniquely identifies the stream segments or reaches that make up the nation's surface water drainage system. For information on the science behind computing perenniality attribution please refer to the following U.S. Geological Survey Scientific Investigative Report (SIR) # 2006-5217 - https://pubs.usgs.gov/sir/2006/5217/pdf/SIR2006-5217_report.pdf

(元数据链接) VHDCARTO 是本地化分辨率佛蒙特州水文数据集（Vermont Hydrographic Dataset, VHD）的简化版本，该数据集增设了溪流常年性（stream perenniality）属性——例如“间歇型”与“常年型”——以及仅针对单一线状要素类的斯特拉勒河流阶数（Strahler stream order）属性。获取该数据集制图信息的主要途径分别为 FCODE 字段与 STREAM_ORDER 字段，详细信息请参见「实体与属性信息」章节。
注意！埃塞克斯县（Essex）与喀里多尼亚县（Caledonia）辖区内或与其相交的河段无常年性数据，因此这些区域的 FCODE 值为"46000"。由于此类区域缺乏土壤调查地理数据库（Soil Survey GeOgraphic, SSURGO）的相关数据，无法开展常年性属性的计算，后续将在未来合适时机对这些区域进行处理。
如需了解用于属性赋值或分析的 FCODE 符号规则，请参阅以下文档：https://www.usgs.gov/national-hydrography/national-hydrography-dataset (NHDFlowline)。
VHDCARTO 还包含湖泊、池塘及大型溪流的二维要素类。上述两个图层均源自最新版国家水文数据集（National Hydrography Dataset, NHD）。NHD 是一套基于要素的数据库，可对构成美国地表排水系统的各河段进行互联并赋予唯一标识符。
如需了解溪流常年性属性计算的相关科学原理，请参阅美国地质调查局《科学调查报告（Scientific Investigative Report, SIR）》第2006-5217号：https://pubs.usgs.gov/sir/2006/5217/pdf/SIR2006_5217_report.pdf