® hydro dwg workshop, quebec rob atkinson, csiro land and water tony boston, australian bureau of...

®

Hydro DWG Workshop, QuebecRob Atkinson, CSIRO Land and Water

Tony Boston, Australian Bureau of Meteorology

June 2013

Australian Geofabric implementation Australian Geofabric implementation of HY_Features of HY_Features

connecting observations, monitoring sites and hydrological connecting observations, monitoring sites and hydrological features using Linked Datafeatures using Linked Data

OGC®

Copyright © 2011, Open Geospatial Consortium, Inc

OverviewOverview

• HY_Features scope and benefits• Implementation within the Australian Hydrological

Geospatial Fabric (Geofabric)– Geofabric development– Methodology and key design decisions– Connecting observations, monitoring sites and hydrological features

using linked data

• Demo• Summary

2

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Copyright © 2011, Open Geospatial Consortium, Inc

Scope of HY_FeaturesScope of HY_Features

• Concerns of the WMO Commission for Hydrology (CHy)– interoperability of observing systems relevant for hydrology– exchange of hydrological data and information on a global scale– sharing of data models and patterns in use in the hydrology domain

• Abstraction of the real-world hydrology phenomena– Features which are the object of study / reporting in hydrology– ... that have properties usually observed in hydrology– ... that are physically / logically connected in networks– ... that have names in cultural, political and historical context– ... that are assigned generally applicable characteristics

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Benefits of HY_FeaturesBenefits of HY_Features

• A common hydrologic feature model– Common terminology: definitions based on WMO standards

(International Glossary of Hydrology)– Supports multiple representations of features at different scales

• Its implementation would support global linkage to hydrological features using standard patterns– River basins and aquifers are hydrological units of study,

management and reporting• Show me all the river basins greater than area W• What is the definition of river basin X or aquifer Y?• What are gauging stations related to river basin Z?

• And allow development of common tools for discovery, access and sharing of hydrologic information– Realising the vision of linked data

Copyright © 2011, Open Geospatial Consortium, Inc 4

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What is the What is the Australian Hydrological Australian Hydrological Geospatial Fabric (Geofabric)Geospatial Fabric (Geofabric)??

1. Evolving and consistent spatial data product …2. that identifies important water features in the

landscape …3. as well as the connections between these features

…4. and supports multiple representations.5. It is a framework to underpin Australia’s water

information activities6. Collaboratively developed by the Bureau of

Meteorology, CSIRO, Geoscience Australia and ANU

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1. Evolving and consistent 1. Evolving and consistent spatial data productsspatial data products

Phased release plan1. Geofabric Phase 1 V1.0

- released 2010

2. Geofabric Phase 2 V2.0 - released 2011

3. Geofabric Phase 2 V2.1 - released 2012

4. Geofabric Phase 3 - beta release 2013

Geofabric products

Reporting Regions

Reporting Catchments

Catchments

Network

Cartography

Groundwater

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2. Identification of 2. Identification of important water important water

featuresfeaturesRiver confluences River outflow to sea

Inland sink Monitored features

Image Source: Bing Maps

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3. Connections between3. Connections betweenwater featureswater features

with different representationsConnected features

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4. Supporting multiple 4. Supporting multiple representations of water representations of water

featuresfeatures

Complex vs Simple Geography Complex vs Simple Topology

Contracted Node

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5. To underpin Australia’s 5. To underpin Australia’s water information water information

activitiesactivities

Water reporting

Visualisation and mapping Catchment contributing areas

Hydrological modelling

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Geofabric product generationGeofabric product generation

Source: CSIRO WIRADA

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• For each of the 34 features within six Geofabric products there is:– a WMS– a Simple Feature WFS– a Complex Feature WFS using

app-schema

Geofabric Web ServicesGeofabric Web Services

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Multiple (scale) Multiple (scale) representationsrepresentations

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Geofabric V2.1 product relationshipsGeofabric V2.1 product relationships

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Mapping HY_Features to the GeofabricMapping HY_Features to the Geofabric Model Mapping Diagram

«FeatureType»AHGF_HR_Catchments::AHGFNode

«property»+ AHGFFType :AHGFNetworkNodeType+ conLevel :Integer+ conNodeID :Integer+ hydroID :Integer [0..1]+ mapNodeID :Integer [0..1]+ nextDownID :Integer [0..1]+ position :GM_Point+ textNote :CharacterString [0..1]

«mappingClass»AHGFNode

«FeatureType»HY_Riv erPositioningSystem::HY_IndirectPosition

+ distanceToRefPoint :HY_DistanceToRefPoint [0..1]+ relativePosition :HY_RelativePosition [0..1]

«FeatureType»AHGF_HR_Catchments::AHGFLink

«property»+ fromConNodeID :Integer+ toConNodeID :Integer+ flowDir :HydroFlowDirections+ hydroID :Integer+ shape :GM_Curve

«mappingClass»AHGFLink

«FeatureType»HY_Catchment::HY_Basin

+ code :ScopedName [0..1]

«FeatureType»AHGF_HR_Catchments::AHGFContractedCatchment

«property»+ AHGFFType :AHGFContractedCatchmentType+ conNodeID :Integer+ hydroID :Integer+ shape :GM_MultiSurface

«mappingClass»AHGFContractedCatchment

«FeatureType»HY_Catchment::

HY_CatchmentArea

+ area :Area [0..1]+ shape :GM_Surface [0..1]

«FeatureTyp...HY_Catchment::

HY_Outfall

«FeatureType»HY_Catchment::HY_ReferencePoint

+ refPoint :GM_Point [0..1]+ refPointType :HY_RefPointType [0..1]

«FeatureType»HY_Catchment::

HY_CatchmentRepresentation

HY_HydroFeature

«FeatureTyp...HY_Catchment::HY_Catchment

+shape

1«representsAttribute»

+shape

1

+referencePoint 1..*

+networkLocation 0..1

+pointOfInflow0..1

+receivingBasin

0..*

+position 1

+contributingBasin

1..*

+pointOfOutflow 1

+drains 1

ContractedCatchmentDrainsToLink

«RelationshipClass»

+drainedBy 0..*

+toNode 1..*+fromNode 1..*

0..*

+representedCatchment 1

«realisedObject»

1 «mapsTo» 1

+outfall

«representsConnector»

+pointOfOutflow

1

«realisedObject»

1

1 «mapsTo» 1

+hydroID

1«representsAttribute»

+code

1+fromNode


+pointOfInflow

+toNode


+pointOfOutflow

1«realisedObject»1

1 «mapsTo» 1

+conNodeId

«representsAttribute»

+id()

1«realisedObject»1

+nextDownID

«representsAttribute»

+receivingBasin.pointOfOutflow

+position1«representsAttribute»

+position.relativePosition.referencePoint.refPoint

1

+outfall 0..*

NodeDrainsContractedCatchment

«RelationshipClass»

+drains 0..*

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Geofabric Hydrology Reporting CatchmentsGeofabric Hydrology Reporting Catchments

Stream Catchment Contracted Catchment

River Regions & Drainage Division

Contracted Catchments,

Nodes and Links

Stream Network

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Australian Catchment BoundariesAustralian Catchment Boundaries

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Geofabric PracticeGeofabric Practice

AHGF Concepts

Requirements Conceptual ModelProduct

ImplementationDocDoc

HY_Features

Otherproducts

ProductModel

Map ID

XSD Services

Link

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Connecting observations, monitoring sites and Connecting observations, monitoring sites and hydrological features using linked datahydrological features using linked data

• Linking related data requires knowing what references mean

• Identifiers must be bound to well-known semantics (what type of thing)

• Binding to a specific data product has issues:– Not portable (don’t do this in standards!)– May not be best representation for user– Fragile (systems change)– Tempting because we probably understand real data....– And a conceptual model not always available

• Enter HY_Features – A common hydrological feature model independent of scale and

implementation


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Sensor Web (image OGC 2006)

Spatial Data Infrastructure

WFS

WCS

Spatialdatabases

Services

http://id.unsdis/id/catchment/567http://id.unsdis/id/catchment/567

URL: spatial data accessURL: spatial data access

URL: observation data archive accessURL: observation data archive access

URL: live data accessURL: live data access

representationsBasic propertiesprovenance

Identifier Architecture

Application (Online or Desktop)

ComputationalModels

URL: virtual data productURL: virtual data product

Linked data and the GeofabricLinked data and the Geofabric

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Contracted nodes and catchmentsContracted nodes and catchments


Topology 1 Topology 2Geometry 1Complex lines and

polygons

Geometry 2Simple line

S1

S1 S1

S1

X=10, Y=3X=14, Y= 4N1 N1

N1N1

N2

‘Contracted’ nodesPersistent identifiers for and connections between nodes in

hydrological network across multiple representations

Streams represented as multiple geometries & topologies

Catchments represented as multiple geometries & topologies

C1

C3C2

C4

C5

C1

C2

C3

C4C5

C1

C2C3

C4 C5

Topology

Geometry

N2

N3`

`

N3`

`

N2`

`N2`

`

Geofabric Core Hydrology Products

(Core ‘contracted’ & ‘non-contracted’ nodes, Nn;

Core catchment boundaries, Cn)

C1

C2

Stream

Flo

w

C3

Monitoring point(Ghost node)

Waterbody nodes

N4

N1

N2

N3

Geofabric Constrained Views

N6

N5

C1

C2

C24

C22

C11

C12

N2

N21

N22

N23

N1

N11

(Head node)

C21

N3

ContractedNon-contracted

C23

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Multiple hydrological representationsMultiple hydrological representations

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Of course the reality is quite messy...Of course the reality is quite messy...


Many network nodes mapped to single logical node...

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Semantics (1) Semantics (1)

• That messiness is inherent• Complex• Handled in the conceptual model• HY_Features used to describe how Geofabric nodes fit

together• Initially through design...

– Next step UML model mappings– OWL ontologies so we can query over relationships


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Semantics (2)Semantics (2)

CSIRO. UN Gazetteer - Common Semantic Framework for the UNSDI

shape:GM_Polygonshape:GM_Polygon

Waterbody

area:GM_Polygonarea:GM_Polygon

Dam

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Identifiers at work…Identifiers at work…

http://water.bom.gov.au/waterstorage/awris/index.html#urn:bom.gov.au:awris:common:codelist:feature:lakepieman

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IdentifiersIdentifiers

• This is the “tricky part”• Lets start with the practical implication…

Catchment Boundary

Area Geometry

1123343 33535.4 151.3344,-35.330…….

Catchment ExtractionRate Storage

1123343 730 300

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““DistributedDistributed”” references references

Catchment ExtractionRate Storage

1123343 730 300

Internet

How to ask for this entity

How to deliver this entity

Catchment Boundary

Area Geometry

1123343 33535.4 151.3344,-35.330…….

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Hydrological ReferencingHydrological Referencing

• Linking hydrological data requires common semantics– Observations apply to what?– How are these objects hydrologically connected?

• Semantics of place– Talking about the same hydrological context

• “The catchment of the Darling River”

• Hydrologic referencing– Hydrologic references more explicit that spatial

coordinates– Names are specific, if we share understanding– Need to “dereference” names/ids to find hydrologic

context.– Multiple products, multiple representations, same ids!

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Unstable Identifier BehaviourUnstable Identifier Behaviour

http://bom.gov.au/ahgf/250K/wfs?featuretype=ahgf_catchment&id=213343

URL for a service

Data Product Feature Type

http://bom.gov.au : organisation name or custodianship changes/ahgf/ : service name or dataset, or something else?/250K : one view/wfs? : one service (+ version!)featuretype=ahgf_catchment : what if we want to add attributes or change model?&id=213343 : is local identifier stable or database row id?

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Separation of concernsSeparation of concerns

See http://web.archive.org/web/20130411044033/http://thismodel.posterous.com/cool-uris-and-geographic-resources

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Multiple ResourcesMultiple Resources

HY_Basin common model

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• http://115.146.86.108/id/geo/ahgf_hrc/100862– Get an index of resources + HY_Basin model view

• ID?_view=ahgf:AHGFContractedCatchment&_format=gml

• Get HR_Catchments product in GML

• ID?_view=alternates

One URI, many resources

Presentation title | Presenter name |

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Generalised Deployment ModelGeneralised Deployment Model

Application ArchitectureApplication Architecture

Identifier ArchitectureIdentifier Architecture

Delivery ArchitectureDelivery Architecture

ServicesServices DownloadDownload WorkflowWorkflow

LID (Linked Data Identifier)

AWRIS GIS HTML Web

Resource listPIDSVC Item

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http://water.bom.gov.au/waterstorage/awris/#urn:bom.gov.au:awris:common:codelist:feature:arthurslake

Definition derived from conceptual model. Linkages can be made to related concepts...

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Summary Summary

• Conceptual model allows us to have “top level” identifiers • HY_Features schema provides basic info about top level

object• Linked Data approach• Multiple representations• AHGF may be delivered by

– Product models (AHGF carto etc)– And HY_Features model– Registered URL ids using data model from HY_Features– alternative data products may evolve and be linked to this

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Take-home...Take-home...

• Be careful not to overspecify references to specific information resources.

• HY_Features is target for relationships in standards– Fix and/or extend if necessary!

• Semantic Web (Ontology) probably best way to traverse relationships – Participation and review welcome.


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Thank youThank you

CSIRO Land and WaterRob Atkinson Principal InvestigatorInteroperable Information Systems

Phone: +61 419 202 973 Email: [email protected]: www.csiro.au

Bureau of MeteorologyTony BostonBranch HeadClimate and Water Data

Phone: +61 2 6232 3503Email: [email protected]: www.bom.gov.au

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