Introduction to NHDPlus: A Framework for

Advanced Water Applications

Introduction to NHDPlus: A Framework for

Advanced Water Applications

Cindy McKay

Horizon Systems Corporation

Cindy McKay

Horizon Systems Corporation

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NHDPlusNHDPlus

1. An integrated suite of application-ready, geospatial, surface water data products

2. First successful national attempt to integrate the NHD, NED, and WBD

3. Used Snapshots of NHD, NED, and WBD

1. An integrated suite of application-ready, geospatial, surface water data products

2. First successful national attempt to integrate the NHD, NED, and WBD

3. Used Snapshots of NHD, NED, and WBD

National Elevation Dataset (NED)

National Hydrography

Dataset (NHD)

Watershed Boundary Dataset (WBD)

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4. NHDPlus links the landscape to the mapped stream network

4. NHDPlus links the landscape to the mapped stream network

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Watershed Boundary Dataset (WBD)added to DEM surface in "walling"technique

NHD stream cellssubtracted fromDEM surface in "burning"technique

NHD Stream Network andWBD Boundaries Enforced into the NED

NHD Stream Network andWBD Boundaries Enforced into the NED

NH

D S

tream C

ells

“burned” into

Elevation

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NHDPlus – What’s Inside?NHDPlus – What’s Inside?NHD Feature Classes & TablesGreatly improved 1:100K National Hydrography Dataset

NED Elevation Grids

PLUS (8 more components):Stream Network Value Added AttributesFlow Direction and Flow Accumulation GridsElevation-based CatchmentsCatchment AttributesFlowline AttributesCumulative Upstream Area AttributesFlow Volume & Velocity EstimatesNetwork Locations of USGS Flow Gaging Stations

NHD Feature Classes & TablesGreatly improved 1:100K National Hydrography Dataset

NED Elevation Grids

PLUS (8 more components):Stream Network Value Added AttributesFlow Direction and Flow Accumulation GridsElevation-based CatchmentsCatchment AttributesFlowline AttributesCumulative Upstream Area AttributesFlow Volume & Velocity EstimatesNetwork Locations of USGS Flow Gaging Stations

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Stream Order

Waterbody Identifier

Network Identifier

Level Path Identifier

Distance to Terminus

Stream Level FromNode/ToNodeHydrologic SequenceDivergence Main PathStart/Terminal FlagsQAQC’ed Connectivity

Table

Network Thinner

NavigationAnalysis

Display/Performance

Value Added Attributes (VAAs)For the Stream Network

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Flow Direction Grid (FDR)Flow Direction Grid (FDR) A 30 meter grid in national Albers

projection Each cell points down hill to the neighboring cell with the lowest elevation Supports “rain drop” tools

A 30 meter grid in national Albers projection

Each cell points down hill to the neighboring cell with the lowest elevation Supports “rain drop” tools

32 64 128

16 1

8 4 2

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Flow Accumulation Grid (FAC)Flow Accumulation Grid (FAC)

A 30 meter grid in national Albers projection

Each cell contains a count of the number of grid cells that drain to that cell

Used to generate a elevation-based “synthetic” stream network

Used to guide basin delineation

A 30 meter grid in national Albers projection

Each cell contains a count of the number of grid cells that drain to that cell

Used to generate a elevation-based “synthetic” stream network

Used to guide basin delineation

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Catchments for Each Stream SegmentCatchments for Each Stream Segment

Definition: The portion of the land surface that drains to a network segment

NHDPlus includes catchments in grid format and as polygons

Definition: The portion of the land surface that drains to a network segment

NHDPlus includes catchments in grid format and as polygons

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Catchments for Each Coastline SegmentCatchments for Each Coastline Segment

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Catchment AttributesCatchment 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)

Headwater Node Area

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)

Headwater Node Area

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Flowline AttributesFlowline Attributes

Raw minimum/maximum elevations

Smoothed minimum/maximum elevations

Slope

Raw minimum/maximum elevations

Smoothed minimum/maximum elevations

Slope

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Cumulative CharacteristicsCumulative Characteristics

Mean Annual Precip and TempNeeded for stream flow estimates

Drainage AreaNeeded for stream flow & velocity

estimates

21 NLCD Land Use CategoriesVery handy to have

Mean Annual Precip and TempNeeded for stream flow estimates

Drainage AreaNeeded for stream flow & velocity

estimates

21 NLCD Land Use CategoriesVery handy to have

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Flow Volume & Velocity EstimatesFlow Volume & Velocity Estimates

Mean Annual Flow volume Two Methods: Unit Runoff &

Vogel

Velocity Jobson Method

Mean Annual Flow volume Two Methods: Unit Runoff &

Vogel

Velocity Jobson Method

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Gage id: 01586500Station Name North Br Patapsco RiverReachcode: 02060003001478Drainage Area: 91 mi2

Max Daily Flow: 3550Avg Daily Flow: 102.4

Plus many flow statistics

Network Locations of USGS Stream GagesNetwork Locations of USGS Stream Gages

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STEP 1

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STEP 2

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STEP 3

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STEP 4

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STEP 5

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STEP 6

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STEP 7

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Value Value Added Added

AttributesAttributes

TemperatureTemperature&&

PrecipitationPrecipitation

Land Land UseUse

Flow Flow Volume Volume

& & VelocityVelocity

STEP 8

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Watershed CharacterizationWatershed Characterization

Main Stem: Huntsville Spring BranchStream Order: 3Stream Level: 4

Area weighted precipitation 1431.2 mmArea weighted temperature 15.3 oC

Land UseOpen Water 1%Residential 28%Commercial/Ind/Trans 9%Barren 1%Forest 33%Pasture/Hay 5%Row Crops 12%Urban/Rec Grasses 5%Wetlands 5%Other 1%

Drainage area 180.5 km2

Mean Annual Flow (UROM) 128.6 cfsMean Annual Flow (Vogel) 123.7 cfs

Mean Annual Velocity (UROM) 0.95 fpsMean Annual Velocity (Vogel) 0.87 fps

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http://nsdi.epa.gov/waters/Click on the “NHDPlus” Linkhttp://nsdi.epa.gov/waters/Click on the “NHDPlus” Link

Questions?Questions?