© OpenStreetMap contributors
Long-term and broad-scale datasets are essential to any investigation of change in natural communities. This dataset includes the collation of aerial imagery for 44 sites around the Welsh coastline, selected to contain rocky shore, saltmarsh or Sabellaria alveolata across temporal scales providing suitable data for comparisons of change through time, both anthropogenic and biological. In order for comparisons to present day imagery, current aerial imagery was also obtained in this study. Photographic aerial images containing features of conservation value (specifically rocky shores, Sabellaria alveolata inhabited shores and saltmarsh areas) within Wales were obtained. Historic photographic aerial images that contained features of conservation value (specifically rocky shores, Sabellaria alveolata inhabited shores and saltmarsh areas) within Wales were selected from expert knowledge and Countryside Council for Wales's collection of habitat maps. The aim of this project was to collate, digitise and georeference aerial photographic imagery for sites that had multi-year overlap. Accuracies of less than 5 m RMS was obtained (with the exception of Treath Lafan, 1995, and the Dyfi Estuary, 1975). At these saltmarsh locations, there were too few ground control points to achieve this accuracy.
Natural Resources Wales (NRW)
The following data is considered OS derived data and is therefore jointly owned by NRW and the Ordnance Survey. NRW may release, publish or disseminate this data freely; providing recipients are made aware of use restrictions (See general use restrictions).
| Other details | ||
| Internal code | Internally assigned metadata identifier | 2971 |
| Title | The title is used to provide a brief and precise description of the dataset such as 'Date', 'Originating organisation/programme', 'Location' and 'Type of survey'. All acronyms and abbreviations should be reproduced in full. | Historic Aerial Imagery to Monitor Temporal Change in Intertidal Habitats |
| Alternative title | The purpose of alternative title is to record any additional names by which the dataset may be known. | Delweddau hanesyddol o'r awyr er mwyn arolygu newid yng nghynefinoedd rhynglanwol tros amser |
| File Identifier | The File Identifier is a code, preferably a GUID, that is globally unique and remains with the same metadata record even if the record is edited or transferred between portals or tools. | 4f4c4942-4343-5764-6473-313135353132 |
| Resource Identifier | This is the code assigned by the data owner. | 115512 |
| Resource type | The resource type will likely be a dataset but could also be a series (collection of datasets with a common specification) or a service. | dataset |
| Start date | This describes the date the resource starts. This may only be the year if month and day are not known | 1969-01-01 |
| End date | This describes the date the resource ends. This may only be the year if month and day are not known | 2013-12-31 |
| Spatial resolution | This describes the spatial resolution of the dataset or the spatial limitations of the service. | inapplicable |
| Frequency of updates | This describes the frequency with which the resource is modified or updated i.e. a monitoring programme that samples once per year has a frequency that is described as 'annually'. | notPlanned |
| Abstract | The abstract provides a clear and brief statement of the content of the resource. | Long-term and broad-scale datasets are essential to any investigation of change in natural communities. This dataset includes the collation of aerial imagery for 44 sites around the Welsh coastline, selected to contain rocky shore, saltmarsh or Sabellaria alveolata across temporal scales providing suitable data for comparisons of change through time, both anthropogenic and biological. In order for comparisons to present day imagery, current aerial imagery was also obtained in this study. Photographic aerial images containing features of conservation value (specifically rocky shores, Sabellaria alveolata inhabited shores and saltmarsh areas) within Wales were obtained. Historic photographic aerial images that contained features of conservation value (specifically rocky shores, Sabellaria alveolata inhabited shores and saltmarsh areas) within Wales were selected from expert knowledge and Countryside Council for Wales's collection of habitat maps. The aim of this project was to collate, digitise and georeference aerial photographic imagery for sites that had multi-year overlap. Accuracies of less than 5 m RMS was obtained (with the exception of Treath Lafan, 1995, and the Dyfi Estuary, 1975). At these saltmarsh locations, there were too few ground control points to achieve this accuracy. |
| Lineage | Lineage includes the background information, history of the sources of data, data quality statements and methods. | Rocky shores sites included Bull Bay, Cemlyn Bay, Cemaes Bay, Holyhead, Penrhyn (East side of Holyhead bay) and Trearddur Bay. Sabellaria sites included Aberaeron, Mochras and Llanddulas and S. alveolata. Those images remaining as photographic prints were digitised using an Epson GT-15000 scanner at 1200 dots per inch (dpi). Images in adjacent locations were mosaicked with the image panorama generating software Autopano Giga 2.6, with a root mean square error (RMS) of less than 5 m where possible. Aerial images were then georeferenced in ArcMap10.0, using Ordnance Survey maps where features were readily visible both on the map and on the image. On occasion, images were georeferenced using aerial imagery that was already georeferenced. Accuracies of less than 5 m RMS was obtained. Georeferenced images were then rectified with the ArcMap10 Nearest Neighbour (for discrete data) function as uncompressed TIFFs, before compression to JPEG format with 100% image quality. Image clarity and descriptions were given for individual images. Spatial reference for all data is British National Grid. Present-day low-altitude imagery was captured with a time-lapse compact Canon camera (D10) with no flash and infinity focus. The camera was attached to either a kite or a helium balloon and led over the sites of interest. The resultant images were mosaicked with Autopano Giga 2.6 achieving the lowest RMS possible and visual clarity. Ground control points were marked during the aerial fly over with a dGPS (Leica GS50 or Magellan MobileMapper 6). On several occasions, dominant habitat types were also walked round in the field providing habitat ground-truthing, logging polylines in the GPS systems. The data from the GPS systems were post-processed using ephemeris data from a fixed station (Morpeth), to achieve accuracies of less than 1.5 m for ground control points and less than 3 m for walk-around data. |
| Related keywords | ||
| Keyword | General subject area(s) associated with the resource, uses multiple controlled vocabularies | Orthoimagery |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Habitat extent | |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Marine Environmental Data and Information Network | |
| Geographical coverage | ||
| North | The northern-most limit of the data resource in decimal degrees | 53.513067 |
| East | The eastern-most limit of the data resource in decimal degrees | -2.608865 |
| South | The southern-most limit of the data resource in decimal degrees | 51.240829 |
| West | The western-most limit of the data resource in decimal degrees | -5.777741 |
| Regional sea | Wales (WLS) | |
| Responsible organisations | ||
| Role | The point of contact is person or organisation with responsibility for the creation and maintenance of the metadata for the resource. | pointOfContact |
| Organisation name | Natural Resources Wales (NRW) | |
| Phone | 0300 065 3000 | |
| Delivery point | Maes-y-Ffynnon | |
| Postal code | LL57 2DW | |
| Role | The distributor is the person or organisation that distributes the resource. | distributor |
| Organisation name | Natural Resources Wales (NRW) | |
| Phone | 0300 065 3000 | |
| Delivery point | Maes-y-Ffynnon | |
| Postal code | LL57 2DW | |
| Role | The custodian is the person or organisation that accepts responsibility for the resource and ensures appropriate care and maintenance. If a dataset has been lodged with a Data Archive Centre for maintenance then this organisation is be entered here. | custodian |
| Organisation name | Natural Resources Wales (NRW) | |
| Phone | 0300 065 3000 | |
| Delivery point | Maes-y-Ffynnon | |
| Postal code | LL57 2DW | |
| Role | The originator is the person or organisation who created, collected or produced the resource. | originator |
| Organisation name | University of Wales, Bangor. School of Ocean Sciences | |
| Phone | 01248 382842 | |
| Postal code | LL57 2DG | |
| Dataset constraints | ||
| Limitations on public access | Any restrictions imposed on accessing the resource such as the need to agree to certain licence conditions. | © CNC/NRW and © Crown copyright 2013. All rights reserved. Natural Resources Wales, 100019741 Third parties seeking to re-use this data require a Licence issued by NRW. It allows re-use, reproduction and dissemination in any format or medium but only for non-commercial purposes, according to the terms and conditions of the Licence. Those seeking commercial re-use require a commercial licence available from the OS. |
| Access constraints (code) | ISO restriction code chosen from ISO 19115-1 Codelist | otherRestrictions |
| Use constraints (code) | ISO restriction name chosen from ISO 19115-1 Codelist | otherRestrictions |
| Use constraints | Any restriction on the use of the resource such as the need to agree to certain licence conditions. | The following data is considered OS derived data and is therefore jointly owned by NRW and the Ordnance Survey. NRW may release, publish or disseminate this data freely; providing recipients are made aware of use restrictions (See general use restrictions). |
| Available data formats | ||
| Data format | Format in which digital data can be provided for transfer | Geographic Information System |
| Version info | ||
| Date of publication | The publication date of the resource or if previously unpublished the date that the resource was made publicly available via the MEDIN network. | 2013-10-31 |
| Date of last revision | The most recent date that the resource was revised. | 2013-10-31 |
| Metadata date | The date when the content of this metadata record was last updated. | 2018-07-03 |
| Metadata standard name | The name of the metadata standard used to create this metadata | MEDIN Discovery Metadata Standard |
| Metadata standard version | The version of the MEDIN Discovery Metadata Standard used to create the metadata record | Version 2.3.8 |
© OpenStreetMap contributors