Presentation on theme: "The National Hydrography Dataset Plus What is NHDPlus?"— Presentation transcript:
1The National Hydrography Dataset Plus What is NHDPlus?
2Vision for a National Geospatial Surface Water Framework National Hydrography Dataset(NHD)National Elevation Dataset (NED)Watershed Boundary Dataset (WBD)How will this vision be attained?
3The Team EPA Project Lead Tommy Dewald Horizon Systems Cindy McKay Jen HillBob DeffenbaughUSGS WRDAl ReaRich MooreCraig JohnstonModeling ConsultantTim Bondelid
4NHDPlus links the mapped stream network An integrated suite of application-ready geospatial surface water data products.It’s the first national effort to integrate:National Hydrography Dataset (NHD)National Elevation Dataset (NED)National Watershed Boundary Dataset (WBD)National Land Cover Dataset (NLCD)NHDPlus links the mapped stream networkto the landscape.
5NHD Plus – What’s Inside? Greatly improved 1:100K National Hydrography DatasetPLUS (9 more components):Value Added AttributesElevation-based CatchmentsCatchment CharacteristicsHeadwater Node AreasCumulative Drainage Area CharacteristicsFlow Direction, Flow Accumulation, and Elevation GridsMin/Max Elevations and SlopesFlow Volume & Velocity EstimatesFlow Gages with Network LocationsNHDPlus evolved from an EPA project intended to produce flow volume and velocity estimates for the stream network in 1:100K NHD.Along the way, we produced a set of very useful components. Obviously the first is (CLICK)READ
6What is the National Hydrography Dataset (NHD)? A Framework dataset that includes:Hydrographic features for making mapsA national stream addressing systemA modeling network for navigating upstream/downstreamA maintenance infrastructureUser updatesDistributed formats – personal geodatabase, shapefiles, coveragesCompatible with ArcHydro Model & ToolsAs the name implies NHDPlus begins with the NHD.Courses on NHD can last the better part of a week. Here is NHD in a single slide.First of all it’s a Framework dataset – that’s framework with a capital F – because the Federal Geographic Data Committee has designated NHD as national framework layer for hydrography.NHD consists of a set of approximately 50 hydrographic feature types that can be used to make maps.NHD contains a national stream addressing system that enables you to tie points (CLICK) such asdrinking water intakes or monitoring stations to positions along the NHD stream network.Or you can tie information such as locations of impairments (CLICK) to stretches along the a stream.The stream network provides a modeling network on which you can navigate upstream and downstream.Possibly one of NHD’s most important characteristics is that it has a maintenance infrastructure that allows and even encourages user updates. All the NHD predecessors (the EPA River Reach Files and the USGS Digital Line Graph datasets) either did not support any updating or didn’t support updates from the user community.NHD is distributed in a variety of formats including pgdb and shapefiles.Finally, NHD is compatible with the ArcHydro data model and the ArcHydro tool set.312ImpairmentDrinkingWaterIntake
7Value-Added Attributes (Stream Order, Stream Level, Waterbody-Network link and more…)A set of two dozen network characteristicsDerived from native NHD contentFor Analysis, Navigation & Display
8Elevation Grid (elev_cm) National Elevation Data (NED) used to create the NHDPlus
9Hydrologically-Conditioned Elevation NationalHydrographyDataset (NHD)WatershedBoundaryDataset (WBD)The first elevation processing step was to hydrologically condition the elevation values.This means that we made the (CLICK) elevation data agree with the (CLICK) watershed boundary dataset and (CLICK)with the NHD dataset.NationalElevationDataset (NED)
10Flow Direction Grid (FDR) Cells point down hillto the neighboring cellwith the lowest elevationFlow Accumulation Grid (FAC)5Cells contains the count of the number of cells that are uphill
11Catchment Grid & Shapefile The portion of the land surface that drains to a network flowline
12Catchment Attributes Mean Annual Temperature (Prism - 4km) Mean Annual Precipitation (Prism - 4km)% of each of the 21 land use classifications from the 1992 National Land Cover Dataset (NLCD)
13Flowline Attributes Raw min/max elevations Smoothed min/max elevations SlopeCumulative drainage areaCumulative land use classificationsFlow volume, incremental inflow – Unit Runoff MethodFlow volume – Vogel MethodVelocity – Jobsen
14USGS Gage Point Events on NHDPlus – Coming Soon! Many Attributes:Gage IDReachcode/MeasureLat/LongAgencyStation NameSeveral Dozen Flow StatsAnd more…We built this file as part of the NHDPlus project.Blind snap to NHD network.QAQC by WRD District OfficesConversion of qaqc’ed locations to reachcodes/measuresDistributed as a shapefile.This was not a totally altruistic exercise. We needed these gages to qaqc our drainage areas and flow volume and velocity.So this is a perfect time to take a break and when we come back Tim will talk about remaining parts of NHDPlus.Before we break, we have a few minutes for questions – does anyone have questions?
15Distribution Units for Elevation, FAC, and FDR Grids 62 units total
16NHDPlus Distribution Units for NHD, Catchments, and Attribute Tables 091710U010402071610L14051811061513080303182012100601020304091107051213141617182003180815
17Linking Data to the NHDPlus Linear Reach:Measure:Point LinksLinear LinksLinear Reach:From Measure: 15.0To Measure:Area LinksWaterbody Reach:shape
18Things Linked to NHDPlus EPA Water ProgramsWater Quality StandardsWater Quality Monitoring StationsAssessed WatersImpaired WatersNonpoint Source ProjectsBeachesFish Consumption AdvisoriesSewage No Discharge ZonesPermitted DischargersDrinking Water IntakesDrinking Water WellsClean Watershed NeedsSpecial Appropriations ProjectsAnd More…USGS Flow GagesRather than creating events, you may chose to use the many, many events that have been tied to NHD by various federal and state agencies. For example, here is the list of events available from EPA.Many EPA Water Programs have been linked to NHD. (CLICK) This is the current list but it’s constantly growing.(CLICK)Some of the event tables are downloadable from the EPA website.
23STEP 1Knowing this is all well and good, except the discharge points on an impaired water are not the only discharge points that we need to be concerned about. The ones upstream of an impaired water may also be important to our analysis. So lets pick an impaired water and use our VAA navigation tool to click on the downstream end of the impairment and (CLICK)
30STEP 8 Value Added Attributes Temperature & Precipitation Flow Volume VelocityLandUse
31Watershed Characterization Main Stem: Huntsville Spring BranchStream Order: 3Stream Level: 4Area weighted precipitation mmArea weighted temperature oCLand UseOpen Water 1%Residential 28%Commercial/Ind/Trans 9%Barren %Forest %Pasture/Hay %Row Crops 12%Urban/Rec Grasses 5%Wetlands 5%Other 1%Drainage area km2Mean Annual Flow (UROM) cfsMean Annual Flow (Vogel) cfsMean Annual Velocity (UROM) 0.95 fpsMean Annual Velocity (Vogel) fpsSo we know that – READWe’ve done all this with just the native NHDPlus content.
32Importance of the NHDPlus The NHDPlus Is a Complete Analytical ToolVery Robust Stream NetworkNew Attributes for Improved ApplicationsCatchments, FDR, FAC and Elevation Add the Landscape into the Analytic EnvironmentWatershed Delineation and CharacterizationIntegration with virtually any landscape datasetModels!!!!
33NHDPlus – What’s Available? Data:Great Lakes (04)Mississippi (05, 06, 07, 08, 10, 11 and 0318)Texas (12)Rio Grande (13)Colorado (14 and 15)Great Basin (16)Pacific Northwest (17)California (18)New England (01)Mid-Atlantic (02)By End of September – South Atlantic (03), Souris-Red-Rainy (09)Documentation:User GuideVarious PresentationsMetadataRelease Notes for each hydro regionTraining:Eight Exercises/TutorialsTools:NHD Flow Table NavigatorNHDPlus VAA Navigator#0 – Preparation#1 – Setting Up The Data#2 – Linking Data to NHD#3 – Navigating with Geometry#4 – Navigating with VAAs & Flow Table#5 – Network Analysis#6 – Raster Dataset#7 – Watershed Delineation#8 – Simple Model
34Where to get NHDPlus Data, Documentation, Presentations, Exercises and Tools Web Site: Click on “NHDPlus”Web Site:FTP Site: ftp://ftp.horizon-systems.com/nhdplusFall 2006: In the EPA Waters Database