SPC Watersheds - HUC-12

The Watershed Boundary Dataset (WBD) is a comprehensive aggregated collection of hydrologic unit data consistent with the national criteria for delineation and resolution. WBD polygon attributes include hydrologic unit codes (HUC), size (in the form of acres and square kilometers), name, downstream hydrologic unit code, type of watershed, non-contributing areas, and flow modifications. The HUC describes where the unit is in the country and the level of the unit. WBD line attributes contain the highest level of hydrologic unit for each boundary, line source information and flow modifications. At a minimum, the HUCs are delineated at 1:24,000-scale. Credits: US Geological Survey (USGS) Watershed Boundary Dataset (WBD), February 2020. Obtained from USDA NRCS Geospatial Data Gateway.

流域边界数据集（Watershed Boundary Dataset，WBD）是一套符合国家汇水区划分与分辨率规范的综合聚合型水文单元数据集。WBD的多边形要素属性包含水文单元代码（hydrologic unit codes，HUC）、面积（以英亩与平方千米为单位）、名称、下游水文单元代码、流域类型、非贡献区以及径流修正项。HUC用于描述该水文单元在全国范围内的位置与所属层级。WBD的线要素属性包含每条边界对应的最高层级水文单元、线要素源信息以及径流修正项。该数据集的水文单元最低制图比例尺为1:24,000。数据致谢：美国地质调查局（US Geological Survey，USGS）2020年2月发布的流域边界数据集（WBD），获取自美国农业部自然资源保护局（USDA NRCS）地理空间数据网关。