INSPIRE Community Forum

New featureType for StatisticalValue in Population Distribution [PD]

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Summary:

Population Distribution (PD) theme has been designed without geometry of its own, having in mind that it will always need Statistical Units (SU) spatial data to be disseminated. GML files created for PD therefore contain no geometry for each statistical value, only a thematic identifier of the respective statistical unit. In order to make the PD data in GML useful, another featureType at the StatisticalValue level is needed.

Detailed description:

The Population Distribution (PD) model contains only one featureType: StatisticalDistribution. This means that the whole distribution, which usually is disseminated for the area of the country, is a single feature. Feature access in WFS gives therefore no value added over predefined dataset download services (e.g. ATOM), since there is no possibility to query for a single statistical value assigned to a specific StatisticalUnit.

The PD model contains one geometry attribute: areaOfDissemination in Statistical Distribution. The attribute represents the whole area for which population data is available (e.g. the whole country). A GML dataset viewed in GIS software is represented by a single polygon (areaOfDissemination) with multiple statistical values. This creates confusion for users.

Proposed solution:

Introducing another featureType in the PD model for StatisticalValue that would acquire geometry from a StatisticalUnit would solve the problem with feature access and usability of GML files.

Discussion topic:

https://themes.jrc.ec.europa.eu/discussion/view/2166/harmonizing-population-grid-data-into-the-inspire-data-model

Comments

  • Bresters PIETER

    I totally agree with this.

  • Pawel SOCZEWSKI

    I agree that the statistical value should become a separate feature type. That solution is more friendly for users of WFS services, it'll allow them to download only really need a set of data according to their needs e.g. only for one clasification or selected clasification items.

    However I don't agree that the statistical value feature type has geometry atributte. The statistical value feature type represents no-geometry type, its spatial reference is realized to reference to statistical unit object, if a user wants to visualize, he may download the geometry from the respective statistical unit and do 'join'. Please note, the GML files are used to exchange data between systems and not for direct visualization in GIS software.