NHDPlus Georeferencing Spatial Quality Assurance

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NHDPlus Georeferencing/Spatial Quality Assurance

• April 30, 2008

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NHD is the linking piece between all of the
different data types
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What are NHD Reaches?
Watershed 02050701
Watershed 02050701 contains 3 NHD reaches
- 02050701000001 - 02050701000002 -
02050701000003 which provide the framework for
stream (reach) addresses in the same manner that
streets do for street addresses
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What is Georeferencing?

• Uses the NHD framework dataset that includes
• Hydrographic features for making maps
• A national stream addressing system
• A modeling network for navigating
• upstream/downstream
• A maintenance infrastructure
• Data and information available at
  http//nhd.usgs.gov

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The WATERS Concept

• Georeferencing to NHD allows databases to be
  linked to position on the earths surface
• Knowing where data in various databases are
  located on the Earths surface allows for
  cross-database analysis
• www.epa.gov/waters

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WATERS Data Architecture
(Watershed Assessment, Tracking Environmental
ResultS) (www.epa.gov/waters)
Reach Address Database (RAD)
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Effluent Guideline Screening Results based on
impaired waters
Water Network (NHD)
Impaired Water - Ammonia
Permitted Facility Outfall - Nitrogen
Monitoring Location
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ImplementingNHDPlus Georeferencing/ Spatial
Quality Assurancein the WQX Data Flow
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How will your sites be indexed?

• You dont need to change anything about your WQX
  submissions
• Additional processing will be made on WQX
  submissions when locations are included
• Additional information will be added to the
  return package that you can use to review your
  location data

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What information is Indexed?

• WQX submission containing
• Monitoring Location ID
• Latitude
• Longitude
• Coordinate System name

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How does Indexing work?

• Latitude and Longitude are used on a Flow
  Direction grid and a line is created to the
  nearest downhill stream

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What is recorded and where?

• Data is recorded in the Reach Address Database -
  RAD
• Monitoring Location ID
• NHD Reach Code
• NHD Reach Measure

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What is recorded in the RAD?
NHD Reach Code
Monitoring Location ID
NHD Reach Measure
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What is the Data Flow for Indexing
XML sent via Internet
WQX Exchange
Central Data
Processing Services
Network Data
Exchange
WQX
Submitter
(
CDX
)
Database
Indexing
Services
WATERS
National STORET
Pending Events
Data Warehouse
Reach Address Database (containing the NHD flow
lines)
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What about Quality Assurance?

• Quality Assurance Service does a type of
  indexing, but to other types of data.
• Other types of data include
• State
• County
• HUC8
• HUC12
• Postal Code

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What information is created?

• Batch Indexing and Quality Assurance Services add
  information to the output XML Document
• Indexed NHD Reach Code
• Indexed NHD Reach Measure
• Indexed NHD Distance to NHD
• Generated State
• Generated County
• Generated HUC8
• Generated HUC12
• Generated Postal Code

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What is the Quality Assurance Flow?
XML sent via Internet
WQX Exchange
Central Data
Processing Software
Network Data
Exchange
WQX
Submitter
(
CDX
)
Database
Indexing
Services
WATERS
National STORET
Pending Events
Data Warehouse
OEI IGD Databases
Reach Address Database (containing the NHD flow
lines)

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What tools are there for review?

• The output XML file will contain warnings if the
  users data is different than the QA Service
  Generated values
• The output XML document will also contain a link
  to a webpage where the input location data and
  the QA data can be viewed on a map, and the QA
  data modified if required.

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How will the map viewer work?

• Opened from URL using the Transaction ID
• Results available in a map window for visual
  navigation
• User can review the input and QA data
• User can modify any QA data

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When will these tools be available?

• Initial development on the tools is done.
• Incorporating the tools into WQX
  June-September, 2008
• Final Testing September October, 2008
• Final Release Targeting November 2008

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Thank You

• For more information, contact Dwane Young
  young.dwane_at_epamail.epa.govJimmy Bisese
  jbisese_at_rti.org