Crosswalk table between 12-digit hydrologic unit code (HUC12) and hydrologic region boundaries

This data release contains a crosswalk between subwatersheds (12-digit hydrologic unit codes; hereafter, HUC12s) and hydrologic regions (sometimes called "Van Metre...本次发布的数据集包含子流域（subwatersheds，其标识采用12位水文单元代码，以下简称HUC12s）与水文区域（有时亦被称为"Van Metre……"）之间的对应关系表。