EMODnet Product Catalogue
Padstow Bay and Surrounds BSH
Feature class depicting broadscale habitat features at The Padstow Bay and Surrounds MCZ. The map is a result of an integrated analysis of existing MBES full coverage of bathymetry and partial coverage of backscatter data from the Civil Hydrography Programme (CHP) and dedicated ground-truthing survey data, collected in 2013. Habitat classes observed at each ground-truthing station were used to inform a semi-automated process of map production using object-based image analysis (OBIA). The map shows the seabed at the site to be characterised largely by outcropping bedrock (ÔÇÿA3.2 Moderate energy infralittoral rockÔÇÖ and ÔÇÿA4.2 Moderate energy circalittoral rockÔÇÖ), with deposits of ÔÇÿA5.1 Subtidal coarse sedimentÔÇÖ in valleys and crevasses in the rock and flat areas of ÔÇÿA5.2 Subtidal sand ÔÇÿ, mainly closer to shore.
Identificatie
| Alternatieve titel | GB001333 |
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| Versiedatum | 2018-04-26 |
| Type versiedatum | Publicatie: Uitgavedatum van de dataset. |
| Versiedatum | 2014-02-13 |
| Type versiedatum | Creatie: Aanmaakdatum of opnamedatum van de dataset. |
| Dataset identificator | GB001333 |
Inhoud
Inhoudelijke beperkingen
Beperkingen van de dataset(serie)
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Contactgegevens dataset(serie)
| Organisatie | DEFRA |
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| open@defra.gsi.gov.uk | |
| Rol | Eigenaar: Partij die eigenaar is van de data. |
Contactgegevens dataset(serie)
| Organisatie | Natural England |
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| enquiries@naturalengland.org.uk | |
| Rol | Beheerder: Partij die verantwoordelijkheid heeft geaccepteerd en zorg draagt voor het beheer van de data. |
Trefwoorden
| GEMET - INSPIRE themes, version 1.0 | Habitats and biotopes |
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| http://inspire.ec.europa.eu/codelist/ReferenceHabitatTypeSchemeValue | Eunis |
| GDI-Vlaanderen Trefwoorden | Metadata GDI-Vl-conform |
| Ruimtelijk schema dataset(serie) | vector: Vector data wordt gebruikt om geografische data te representeren. |
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Ruimtelijke resolutie dataset(serie)
| Noemer | 4000 |
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| Taal | Engels |
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| Categorie(ën) |
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Begrenzing
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Omschrijvende rechthoek
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| Identificator geografische begrenzing | |||||||||
Referentiesysteem
Horizontaal en/of verticaal referentiesysteem
| Unieke code | WGS 84 (EPSG:4326) |
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| Codespace | EPSG |
Kwaliteit
| Niveau kwaliteitsinformatie | Dataset: Informatie heeft betrekking op de dataset. |
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Bewerkingen
| Algemene beschrijving herkomst | The Padstow Bay and Surrounds MCZ overlaps with an area of existing Multibeam Echosounder (MBES) bathymetry and backscatter data acquired by the Maritime and Coastguard Agency (MCA) under the Civil Hydrography Programme (CHP). Consequently, no dedicated acoustic survey was carried out at the site. The MBES bathymetry covers most of the site. Backscatter is available from two survey blocks (Figure 2). Ground-truth sampling for the site was planned using an existing bottom texture dataset created by the MCA based on their survey data. The bottom texture categories are not directly translatable to BSH, but the dataset enabled the placement of sampling stations equally on different bottom types The full array of stations, with the MCA interpretation of bottom texture, is illustrated below, in Figure 3. Sampling equipment comprised a 0.1 m2 mini Hamon grab. On recovery, the grab was emptied into a large plastic bin and a representative sub-sample of sediment (approx. 0.5 litres) taken for Particle Size Analysis (PSA). The remaining sample was photographed and sieved over a 1 mm mesh sieve to collect the benthic fauna. Fauna were preserved in buffered 4% formaldehyde for later processing ashore. See the survey report for details of the sediment sampling methodology (Godsell 2013). Video footage and still images of the seabed were collected with an underwater camera system and sediment type determined by the use of grab samples. The camera images helped to characterise surficial sediments and associated epifaunal communities. The camera was mounted on a drop down frame with two high intensity LED strip lights and collected both video and still images. A reference scale was used in the video and still images. Set-up and operation followed the MESH ÔÇÿRecommended Operating Guidelines (ROG) for underwater video and photographic imaging techniquesÔÇÖ (Coggan et al., 2007). Video was recorded simultaneously to a Sony GV-HD700 DV tape and a computer hard drive. A video overlay was used to provide station metadata, time and GPS position (central reference point of the vessel) in the recorded video footage. Camera tows lasted a minimum of 10 minutes, with the sledge towed at ca. 0.5 knots (ca. 0.25 m s ÔÇô1 ) across a 100 m diameter ÔÇÿbullringÔÇÖ centred on the sampling station. Still images were captured at regular 10ÔÇô15 m intervals and also opportunistically if specific features of interest were encountered. Video and still images were analysed Padstow Bay and Surrounds MCZ Post-survey Site Report 9 following an established protocol used by Cefas and the JNCC (Coggan and Howell 2005; JNCC, in prep.; see Annex 5). In all, 64 ground-truth stations were visited (Figure 3). Hamon grabs were successful at 27 stations and successful drop camera deployments were completed at all 64 stations. Station metadata are presented in Appendix 1. For further detail on ground-truth sample collection see the Padstow Bay and Surrounds rMCZ Survey Reports (Godsell, 2013; Ware, 2013). All new maps and their derivatives have been based on a WGS84 datum. A new habitat map for the site was produced by analysing and interpreting the available acoustic data (as detailed above) and the ground-truth data collected during the dedicated survey of this site. To make use of the best available data, the habitat map was produced as a combination of three separate analyses of the existing acoustic data and the newly acquired ground-truthing data. A habitat map covering the whole area with MBES bathymetry coverage (Figure 2) was produced using only the bathymetry and its derivatives (Map 1). The CHP backscatter data was acquired during two surveys using different MBES systems on board different vessels and has therefore been treated as two separate datasets. Consequently, separate maps were produced for backscatter block 1 (Map 2) and block two (Map 3) including bathymetry, bathymetry derivatives and backscatter layers in the analysis. The three maps were combined to form the final habitat map by giving preference to the most accurate map where they overlapped. To produce the updated habitat map, the segmentation objects in Maps 1, 2 and 3 were classified into ÔÇÿA3.2 Moderate energy infralittoral rockÔÇÖ, ÔÇÿA4.2 Moderate energy circalittoral rockÔÇÖ, ÔÇÿA5.1 Subtidal coarse sedimentÔÇÖ and ÔÇÿA5.2 Subtidal sandÔÇÖ according to the cut-off values identified in the three CI analysis for the appropriate variables. In Maps 2 and 3, patches of noise were clearly identifiable by their narrow rectangular shape, even spacing and much lower backscatter values from the surrounding objects. All objects identified as noise, were merged into their surrounding objects. The resulting final classified objects were exported into GIS, dissolved into continuous polygons and the map was simplified by reclassifying polygons smaller than 200 m2 into the surrounding habitat type. The three maps were merged into one map, with Maps 2 and 3 taking preference over Map 1 in areas of overlap. |
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Conformiteit
Domeinconsistentie
Resultaat
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Domeinconsistentie
Resultaat
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Toegangs- en gebruiksbeperkingen
Legale en veiligheidsbeperkingen
Beperkingen van de dataset(serie)
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Distributie
| Distributieformaat | ESRI Shapefile (Version: 1.0) | ||||||||||||||||||||||||||||||||||||||||||||||
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Overdracht
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Meta-metadata
| Metadata identificator (fileIdentifier) | d61365c0-ba62-4f81-a7d6-38c06d94115b | ||||||
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| Taal metadatarecord | Engels | ||||||
| Karakterset metadatarecord | MD_CharacterSetCode_utf8: MD_CharacterSetCode_utf8 | ||||||
| Hiërarchisch niveau | Dataset: Informatie heeft betrekking op de dataset. | ||||||
| Metadata wijzigingsdatum | 2020-01-15T12:07:48 | ||||||
| Naam metadatastandaard | ISO19115 | ||||||
| Versie metadatastandaard | 2003/Cor.1:2006 | ||||||
Metadata-auteur
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