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1 Challenge the future INSPIRE coverages Modelling Land Use coverages for INSPIRE

1 Challenge the future INSPIRE coverages Modelling Land Use coverages for INSPIRE

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1Challenge the future

INSPIRE coveragesModelling Land Use coverages for INSPIRE

2Challenge the future

Overview

• Land Use in INSPIRE• Introduction to coverages• Land use modeling• Land use coverages

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INSPIRE: Land Use

My task:Make an information model for Land Use according to INSPIRE rules

Definition of Land Use:Territory characterised according to its current and future planned functional dimension or socio–economic purpose (e.g. residential, industrial, commercial, agricultural, forestry, recreational).

Ground rule of land use experts:Each piece of land has exactly one land use category! No gaps (category UNUSED) no overlap (category MULTIPLE LAND USE) Land Use is a Coverage!

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Coverages

• feature that acts as a function to return values from its range for any direct position within its spatial, temporal or spatiotemporal domain

In modeling a coverage is defined by defining a type for its domain and range

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Main characteristic of Coverage

Continuous

(useful interpolation in range values)

Discrete

(interpolation on range is useless)

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Coverage implementation

Different implementations•Raster/Grid •Topological Structure•TIN•Collection:

• Points• Lines + interpolation method• Polygons

Choice depends on:•The way the data is acquired•The way the data is used•Storage considerations

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Raster Coverage

• Continuous

• Discrete

Efficient encoding in files:-Implicit domain geometry-Range values can be compressed

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Topology Coverage

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TIN Coverage

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Point coverage implementation

•Continuous •Discrete

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Line coverage implementation

•Continuous •Discrete

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Polygon coverage implementation

•Continuous •Discrete

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Categorizing land use Coverages

• Coverages are always discrete (no interpolation)• Land use is a discrete coverage in all member states

implemented as:• Raster coverage• Polygon coverage• Point coverage (LUCAS)

copyright Eurostat 2011

LUCAS: Land cover dataset for Europe

1 100 000 points

LAND COVER classes1 ARABLE LAND2 PERMANENT CROPS 3 GRASSLAND4 WOODED AREAS AND SHRUBLAND5 BARE LAND, RARE VEGET.6 ARTIFICIAL LAND7 WATER

First phase sample for stratification: orthophoto interpretation

2km squared grid

Ground survey

Parameters•Land cover•Land use•pictures•etc.

Sample of around 260,000 pts

Second phase sample: in-situ data collection

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LUCAS (Land use/cover area frame survey

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Land Use Range

• The classification value is a complex object Land Use is always a discrete coverage

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What does INSPIRE offer

• In the Proposed Changes to the Generic Conceptual Model and Encoding Guidelines one chapter about coverages

• Based on ISO 19123 Coverages and ISO 19136• Two coverage hierarchies:

1. Coverage-As-Polygon-Value-Pair2. Coverage-By-Domain-And-Range

«featureType»Coverages (Base)::Coverage

«featureType»Coverages (Domain and Range)::

CoverageByDomainAndRange

«featureType»Coverages (Geometry-Value Pairs)::

DiscreteCoverageGeometryValuePairs

«type»Coverage Core::CV_Coverage

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Discrete Coverage Geometry Value Pairs Model

Discrete point coverage

Discrete polygon coverage

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Coverage by Domain and Range model

Discrete coverage

here

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Coverage by Domain and Range

Discrete point

coverage

Discrete surface

coverage

Discrete grid

coverage

This shared superclass I chose as base class for Land Use

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Land Use Coverage as a DiscreteCoverage

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Now the encoding part.

• The UML diagram model is automatically translated to a GML application schema.

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Implementation of Coverage by Domain and Range

Four options for Range:•ValueArray

homogeneous arrays of primitive and aggregate values.

•AbstractScalarValueListList of scalar values

•DataBlockTuples of values are stored as a long list of Comma Separate Values.

•FileActual data is stored in a file outside GML

Not what I want

Not what I want

What I want but not the way I want it.

Might be right for gridded data.

So I went for a Coverage by Geometry Value Pairs

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Implementation of Coverage by Geometry-Value-Pairs

It works but….

Hi Wilko,

I had a quick look and there are quite a number of issues in the XML so I would suggest not to present it as a sample template.

I am also convinced that the coverage representation is not the right way, but that is a separate issue.

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Conclusions / Limitations

• INSPIRE coverage model is unclear: Why do we have two types of coverages in the top of the hierarchy?

• INSPIRE coverage implementation wrong: Why do I have to provode a domain and range if I want to encode a Coverage-by-geometry-value-pair?

• Now I have GML but how to serve it Efficiently (WCS???)

Time for a major revision of coverages in: INSPIRE, OGC and ISO/TC 211