Watershed Boundary Dataset

This data set is a digital hydrologic unit boundary layer that is at the Subwatershed (12-digit) level. The original data set was developed by delineating the boundary lines on base USGS 1:24000 scale topographic quadrangle, and digitizing the delineated lines. Digital Raster Graphics (DRG) images were used for edits to the data layer. This data set consists of geo-referenced digital map data and attribute data. The spatial data are in a statewide coverage format and include complete coverage of the entire state of Connecticut, and small parts of surrounding states. The hydrologic unit ID code attached to each delineated polygon is linked to the attribute data.本数据集为12位亚流域（Subwatershed）层级的数字水文单元边界图层。该原始数据集依托基础美国地质调查局（USGS）1:24000比例尺地形标准图幅，通过勾绘边界线并对勾绘结果进行数字化处理构建而成。研究团队采用数字栅格地图（Digital Raster Graphics, DRG）影像对该数据图层开展编辑修正工作。本数据集包含地理参考数字地图数据与属性数据两类核心内容。空间数据采用全州覆盖格式，完整覆盖康涅狄格州全域，同时包含周边州的少量区域。附着于每个勾绘面状要素的水文单元标识码，均与属性数据建立关联。