The National Hydrography Dataset in the Pacific Region. U.S. Department of the Interior U.S. Geological Survey

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1 The National Hydrography Dataset in the Pacific Region U.S. Department of the Interior U.S. Geological Survey

2 The National Map The National Map is built on partnerships and standards The National Map consists of eight data layers: hydrography, elevation, orthoimagery, geographic names, boundaries, transportation, land cover, structures Public domain data support topographic maps at 1:24,000-scale products and services at multiple scales and resolutions analysis, modeling, and other applications at multiple scales and resolutions

3 What is the National Hydrography Dataset? Essentially the surface water features found on topographic maps

4 The National Map Map Portal

5 NHD Stewardship Program Critical need for local knowledge to help maintain NHD State (and sometimes local/regional/federal) agencies are best suited for stewardship roles Stewards are responsible for all features in their jurisdiction Revised data are processed into national holdings Stewards and USGS enter into an agreement outlining terms and conditions

6 USGS Pacific Region (Realigned 2012)

7 Pacific Region (Pacific Basin detail)

8 California status Multiple sub-stewards Multi-agency MOU draft in work Projects with CSU Northridge (conflation, state updates; Los Angeles County (stormwater drainage) Other NHD contributors (CA Water Boards, US Forest Service) Numerous instructor-led and online training classes held in state Connecting to community through s and conference calls

9 Nevada status Several local, state, federal groups looking at updating data in regional stewardship roles Beginning discussion with state on NHD updates Instructor-led and online training provided

10 Hawai i status Agreement in place multiple organizations Phase 1 of NHD updates completed in 2011 Primary goal of updates aimed at network connectivity Look at a new phase to include local resolution data and further photorevision Look at related data such as new lidar (Oahu now) Geographic names project to link local stream names to unnamed tributaries on Island of Hawai i

11 Pacific Basin status Project underway with Guam for WBD and NHD updates, complete by end of September 2014 Project starting with American Samoa for WBD and NHD updates

12 Guam NHD UPDATE LiDAR-derived Hydrologic Model of Southern and Central Guam Maria Kottermair ESRI User Conference 2014 San Diego, July 15, 2014 U.S. Department of the Interior U.S. Geological Survey

13 U.S. Territory in the Pacific

14 Available Datasets River datasets (3+) Watershed boundaries (3+) No Microdrainages No raster datasets (e.g. flow accumulation) for hydrologic modeling => No high-resolution datasets!

15 Objectives Create high-resolution hydrologic model based on 2007 LiDAR data Updated watershed boundaries Updated stream layer consistent with other LiDAR- derived data Micro basin delineation Flow direction and accumulation (e.g. contaminant tracing) Update NHD/ WBD based on new stream lines

16 Data & Tools Input: 2-m LiDAR-derived digital elevation model (DEM) For reference: satellite imagery and USGS hydrolines ArcGIS 10.1 Extensions: Spatial Analyst ArcHydro Modelbuilder Semi-automated approach!

17 Application

18 Simple Workflow Overview LiDARderived DEM Fill sinks Flow direction Flow accumulation Stream definition Watershed Delineation

19 Simple Workflow Result

20 Adjusted Workflow Overview LiDARderived DEM Flow direction Flow accumulation Stream definition Watershed Delineation Hydro- DEM Hydrologically connected DEM -> time-intense!!! Manual editing! In addition for better result: -> on-screen digitizing of major rivers! (based on LiDAR-derived DEM & slope raster)

21 Hydrologically Connected DEM Artificial sinks -> small: Fill -> large: Remove barriers Real sinks: Don t fill!

22 Barrier removed and small sinks filled!

23 Comparison of flowlines Simple Fill Conditioned DEM

24 High-resolution drainage lines

25 Products

26 NHD Update Streams/Rivers Edit streamlines from model Delete small tributaries (<200m) and where no riverbed Check topology Coastline Create new feature class Based on LiDAR breakline and C-CAP classification Waterbodies Updated existing shapefile Based on LiDAR and satellite imagery

27 NHD Update

28 Next steps Integrate Data into the National Hydrography Dataset (NHD) and Watershed Boundary Dataset (WBD) Make final edits using the NHD Editor toolbar

29 Acknowledgements U.S. Geological Survey Government of Guam University of Guam Brian Quinn Marin County

30 Drew Decker Carol Ostergren Maria Kottermair USGS Pacific Region USGS Pacific Region University of Guam San Diego, CA Sacramento, CA Mangilao, GU office office office cell cell Questions? Further discussion? Handouts? Stop by the USGS booth.