Elevation-Derived Hydrography Acquisition Specifications Chapter 11 of Section B, U.S. Geological Survey Standards, of Book 11, Collection and Delineation of Spatial Data Techniques and Methods 11–B11 U.S. Department of the Interior U.S. Geological Survey AAXXXX_fig 01 Cover. Examples of elevation-derived hydrography in different landscapes. From top to bottom, (1) a stream network running through mountains in Virginia; (2) stream channels flowing from a mountainous area, through a lake, and into farmland in Colorado; (3) stream channels in an arid location in Colorado; and (4) canals and other water features along the coast of North Carolina. Elevation-Derived Hydrography Acquisition Specifications By Silvia Terziotti and Christy-Ann M. Archuleta Chapter 11 of Section B, U.S. Geological Survey Standards, of Book 11, Collection and Delineation of Spatial Data Techniques and Methods 11–B11 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior DAVID BERNHARDT, Secretary U.S. Geological Survey James F. Reilly II, Director U.S. Geological Survey, Reston, Virginia: 2020 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment—visit https://www.usgs.gov or call 1–888–ASK–USGS. For an overview of USGS information products, including maps, imagery, and publications, visit https://store.usgs.gov/. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. Suggested citation: Terziotti, S., and Archuleta, C.M., 2020, Elevation-Derived Hydrography Acquisition Specifications: U.S. Geological Survey Techniques and Methods, book 11, chap. B11, 74 p., https://doi.org/ 10.3133/ tm11B11. ISSN 2328-7055 (online) iii Contents Abstract ...........................................................................................................................................................1 Introduction.....................................................................................................................................................1 Purpose and Scope .......................................................................................................................................1 Applicability ....................................................................................................................................................1 Product Descriptions.....................................................................................................................................1 Hydroflattening Breakline Feature Collection ..................................................................................1 Elevation-Derived Hydrography Feature Collection .......................................................................2 Requirement Terminology .............................................................................................................................2 Background.....................................................................................................................................................2 Related Data Requirements and Specifications ..............................................................................2 3D Elevation Program Light Detection and Ranging Base Specification ...........................2 National Hydrography Dataset Specifications Explorer �������������������������������������������������������3 Elevation-Derived Hydrography Acquisition Specifications ..................................................................3 Collection Area ��������������������������������������������������������������������������������������������������������������������������������������3 Collection Concurrent with Elevation .......................................................................................3 Collection Area from Existing Elevation Data .........................................................................3 Spatial Reference System ...................................................................................................................6 Datums ...........................................................................................................................................6 Attribute Table Structure .....................................................................................................................6 Feature Codes and Values ...................................................................................................................7 3D Elevation Program Light Detection and Ranging Base Specification Required Hydroflattening Features .............................................................................7 Additional User-Defined Features .............................................................................................7 Features Outside the Scope of this Specification ���������������������������������������������������������8 Refinement of FCode with National Hydrography Dataset Feature Codes ...............8 Delineation of Hydrographic Features ............................................................................................10 3D Elevation Program Light Detection and Ranging Base Specification Required Hydroflattening Collection .........................................................................10 Elevation-Derived Hydrography Feature Collection ............................................................10 Minimum Set of Features ................................................................................................10 Additional Features ..........................................................................................................10 Ancillary Data Sources .............................................................................................................16 Special Cases .............................................................................................................................16 12-Digit Hydrologic Unit Consistency ............................................................................16 Culverts ...............................................................................................................................19 Delineation ................................................................................................................22 FCode Assignment ...................................................................................................22 Drainageway .....................................................................................................................29 Headwaters at Roads .......................................................................................................30 Canals and Ditches ...........................................................................................................32 Summary of Delineation Rules ................................................................................................34 Topology ...............................................................................................................................................34 Topology Rules ...........................................................................................................................34 Z-Values ���������������������������������������������������������������������������������������������������������������������������������������35 iv Positional Assessment .......................................................................................................................35 Elevation-Derived Hydrography Positional Evaluation and Reporting .............................35 Positional Assessment and Reporting ..........................................................................36 Hydroflattening Polygon Exception ......................................................................36 Vertical Positional Assessment of Hydrographic Features Relative to the Digital Elevation Model ......................................................................................36 Horizontal Positional Assessment of Elevation-Derived Hydrography ....................36 Linear Features ........................................................................................................36 Polygonal Features ..................................................................................................38 Point Features ..........................................................................................................38 Alignment ....................................................................................................................................38 Horizontal Alignment ........................................................................................................38 Vertical Alignment ............................................................................................................38 Completeness .............................................................................................................................40 Metadata ..............................................................................................................................................40 Delivered Products and Formats