NHD Line

This dataset includes line data that are contained by a subbasin that overlaps the 16-county NCTCOG region. The data are extracted from the NHD. The NHD is a digital vector dataset that contains features such as lakes, ponds, streams, rivers, canals, dams and stream gages. NHD Lines dataset represents linear NHD hydrographic landmark features used for cartographic representation. . For more information about NHD features, see the Feature Catalog at http://nhd.usgs.gov/FeatureDirectory.swf. The NHD is a combination of USGS hydrologic digital line graph files (DLG) and EPA reach files, version 3.0 (RF3). The USGS files were used for spatial accuracy and the EPA files were used for attribute information. This dataset was downloaded from http://nhd.usgs.gov/data.html and processed but otherwise unaltered. This file is for reference use only. NCTCOG and its members are not responsible for errors or inaccuracies in the file.本数据集包含与16县北德克萨斯中部区域委员会（NCTCOG）辖区重叠的子流域内的线状数据。此类数据提取自国家水文数据集（NHD）。国家水文数据集（NHD）为数字化矢量数据集，涵盖湖泊、池塘、溪流、河流、运河、水坝及河道测站等水文要素。NHD线状数据集指代用于制图表达的线状NHD水文地标类要素。如需了解NHD要素的详细信息，请访问要素目录：http://nhd.usgs.gov/FeatureDirectory.swf。国家水文数据集（NHD）由美国地质调查局（USGS）水文数字线划图（DLG）文件与美国环境保护署（EPA）3.0版河段文件（RF3）整合而成。其中USGS文件用于保障空间精度，EPA文件则用于提供属性信息。本数据集从http://nhd.usgs.gov/data.html下载并经过处理，但未做其他修改。本文件仅可用于参考用途。北德克萨斯中部区域委员会（NCTCOG）及其成员不对本文件中的错误或不准确内容承担责任。