All Wales Phase 1 Terrestrial - Vegetation Layer - Voronoi
Haen Llystyfiant Tir Cymru Gyfan - fersiwn Voronoi

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  • wel
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This is a GIS dataset containing spatial polygons showing the boundaries and attributes of vegetation polygons.


A voronoi procedure was applied to the All Wales Phase 1 Terrestrial - Vegetation Layer - GIS dataset to subdivide upland mixed habitat polygons into their component habitats as identified by the All Wales Phase 1 Terrestrial - Habitat Layer - GIS dataset. New polygons derived by the voronoi procedure have Voronoi_UID's prefixed 'v_'. New polygons created from Habitat Layer points mapped with a string of habitats, e.g. D.1.1 + D.2/E.2.1, are attributed 'mosaic' in the Phase 1 Code field, and the component habitats and their proportions are listed in the Mosaic browser table (see metadata for All Wales Phase 1 Terrestrial - Mosaic Layer voronoi - GIS dataset). The two tables link on the Voronoi_UID field. The Phase 2 Tools were used to create a mospolys (mosaic polygons) layer to which the Phase 1 legend can be applied for better visualisation in GIS.


The original field surveys were carried out as part of a national habitat survey programme required to implement conservation at a local level. An all-Wales 1km square dataset was created for the generation of national statistics on habitat coverage, and the maps were digitised as part of the mapping of Open Access land. The dataset was subsequently imported into a GIS to enable its disaggregation into various different geographical regions within Wales.


Voronoi was carried out to enable full representation and visualisation of the components of complex mixed-habitat upland polygons in the vector data.

Identification

Dynodydd
Identifier
NRW_DS115875
Teitl Amgen
Alternative Title
  • Phase 1 Vegetation voronoi.lyr
Laith Metadata
Metadata Language
English
Lineage

Voronoi procedure carried out on the cleaned version of the vegetation layer (see metadata for Terrestrial Phase 1 Habitat Survey).


Closely co-ordinated teams of surveyors carried out field recording of habitats onto 1:10,000 scale maps (rarely 1:25,000 during the upland stage). The minimum size of habitat patch recorded lies predominantly within the range 0.1-0.25 ha, although smaller areas were mapped in the lowlands. The survey methods employed during the initial upland stage are given in more detail in a WFU report (Day, A. (1989) Upland Vegetation Survey 1979-1989 Background Methodology and Summary of Data Collected. NCC, Bangor). Methods for the lowland survey followed the Handbook for Phase 1 Habitat Survey with some minor modifications adopted for use in Wales (Howe E.A. and Blackstock T.H. (1991) Supplementary Notes for Phase I Survey in Wales. CCW, Bangor).


The voronoi procedure was carried out in MapInfo to split complex upland mixed habitat polygons into component parts using a tool written in-house by the GIS and Spatial Data Team. All field mapping was carried out by trained and closely co-ordinated teams of surveyors. A study of survey reliability was conducted during the lowland phase (Kerry, Rimes, Smith, Williams. 1994. An Assessment of Errors in Phase I Habitat Survey in Wales. Bangor: Countryside Council for Wales, Report No. 94/4/1). It showed the field mapping to be 83% repeatable (Stevens, Blackstock, Howe, Stevens. 2004. Repeatability of Phase 1 habitat survey. J. Environ. Manage. 73, 53-59).The electronic data have undergone a series of checks for accuracy both by the contractor and subsequently within CCW. The extent of habitats that tend to occur in small patches such as upland flush and upland species-rich ledges may be over-estimated by the voronoi procedure.
Additional Information

Voronoi maps are constructed from a series of polygons formed around the location of a sample point. Voronoi datasets form a derived mosaic allowing statistically derived polygons to be created from point data.
Dyddiad cyfeirnod y set ddata (Cyhoeddiad)
Dataset Reference Date (Publication)
2014-11-20
Perchennog
Owner
  Natural Resources Wales (NRW)
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
Cychwynnwr
Originator
  Natural Resources Wales (NRW)
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
 

Extent

Extent

Hyd
Geographic Extent
Wales (WLS)
N
W
E
S
Map representing the geographic extent of the dataset


 
 

Distribution

Fformat - Math a Disgrifiad
Format Type and Description
  • Geographic Information System ( )

    Specification

    ESRI Feature Class

 

Quality

Ansawdd Data
Data quality

Cwmpas Ansawdd
Quality Scope
Dataset
Dataset
Cydymffurfiad
Conformity
Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services
Explanation

This dataset has not been assessed for conformance to the referenced INSPIRE regulation.
Degree
false
Lineage

Voronoi procedure carried out on the cleaned version of the vegetation layer (see metadata for Terrestrial Phase 1 Habitat Survey).


Closely co-ordinated teams of surveyors carried out field recording of habitats onto 1:10,000 scale maps (rarely 1:25,000 during the upland stage). The minimum size of habitat patch recorded lies predominantly within the range 0.1-0.25 ha, although smaller areas were mapped in the lowlands. The survey methods employed during the initial upland stage are given in more detail in a WFU report (Day, A. (1989) Upland Vegetation Survey 1979-1989 Background Methodology and Summary of Data Collected. NCC, Bangor). Methods for the lowland survey followed the Handbook for Phase 1 Habitat Survey with some minor modifications adopted for use in Wales (Howe E.A. and Blackstock T.H. (1991) Supplementary Notes for Phase I Survey in Wales. CCW, Bangor).


The voronoi procedure was carried out in MapInfo to split complex upland mixed habitat polygons into component parts using a tool written in-house by the GIS and Spatial Data Team. All field mapping was carried out by trained and closely co-ordinated teams of surveyors. A study of survey reliability was conducted during the lowland phase (Kerry, Rimes, Smith, Williams. 1994. An Assessment of Errors in Phase I Habitat Survey in Wales. Bangor: Countryside Council for Wales, Report No. 94/4/1). It showed the field mapping to be 83% repeatable (Stevens, Blackstock, Howe, Stevens. 2004. Repeatability of Phase 1 habitat survey. J. Environ. Manage. 73, 53-59).The electronic data have undergone a series of checks for accuracy both by the contractor and subsequently within CCW. The extent of habitats that tend to occur in small patches such as upland flush and upland species-rich ledges may be over-estimated by the voronoi procedure.
 

Keywords

Allweddair
Keywords

GEMET - INSPIRE themes, version 1.0
Math
Type
Theme
Theme

Dyfyniad
Citation

Dyddiad (Cyhoeddiad)
Date (Publication)
2008-06-01
Code
geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme

Allweddair
Keywords

NRW Thesaurus
  • lowlands
  • Phase 1 Habitat Survey
  • future of the uplands
Math
Type
Theme
Theme

Dyfyniad
Citation

Dyddiad (Cyhoeddiad)
Date (Publication)
2024-06-19
Code
geonetwork.thesaurus.local.theme.converted_nrw-keywords
 

Spatial Reference System

Code
British National Grid (EPSG::27700)
 

Content

Gwybodaeth Cynnwys
Content Information

Proffil CNC
NRW Profile

Elfennau CNC
Custom Elements

NRW Related Title

Upland vegetation survey 1979-1989 : background, methodology and summary of data collected
NRW Related Title

Supplementary notes for phase 1 survey in Wales
NRW Related Title

An assessment of errors in Phase I habitat survey in Wales. Confidential
 

Constraints

Constraints

Limitations on Public Access and Use

Math o Gyfyngiad
Restriction type
Other restrictions
Other restrictions
 

Access Constraints Directive

Limitations
no limitations
 

Access Constraints Text

Other constraints

There are no access restrictions on this data. NRW may release, publish or disseminate it freely.
 

Use Constraints

Cyfyngiadau Defnyddio
Use constraints type
Other restrictions
Other restrictions
Other constraints

© CNC/NRW All rights Reserved. Contains Ordnance Survey Data. Ordnance Survey Licence number AC0000849444. Crown Copyright and Database Right Data may be re-used under the terms of the Open Government Licence providing it is done so, acknowledging both the source and copyright of the owners. It is the recipient's responsibility to ensure the data is fit for the intended purpose.
 

Attribution Statement

Other constraints

Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved. Contains Ordnance Survey Data. Ordnance Survey Licence number AC0000849444. Crown Copyright and Database Right.
 

Licence

Other constraints
Open Government Licence
 
 
 

Metadata

Metadata

Dynodydd Ffeil
File Identifier
4f4c4942-4343-5764-6473-313135383735 XML
Laith Metadata
Metadata Language
English
Parent Identifier
Terrestrial Phase 1 Habitat Survey

NRW_DS24715
Math o adnodd
Resource type
Dataset
Dataset
Dyddiad Metadata
Metadata Date
2025-02-04T10:30:35.674Z
Enw Safonol Metadata
Metadata Standard Name
NRW
Fersiwn Metadata
Metadata Standard Version

1.0

Pwynt Cyswllt
pointOfContact
  Natural Resources Wales (NRW)
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
 
 

Publishing Body

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