03b62fd0-41e2-4355-9a06-1697117f0717 English ISO/IEC 8859-1 (also known as Latin 1) dataset dataset NERC EDS Environmental Information Data Centre Lancaster Environment Centre, Library Avenue, Bailrigg Lancaster LA1 4AP UK info@eidc.ac.uk https://eidc.ac.uk/ EIDC website The Environmental Information Data Centre (EIDC) is the UK's national data centre for terrestrial and freshwater sciences. information pointOfContact 2025-11-13T16:16:01 UK GEMINI 2.3 OSGB 1936 / British National Grid Change in saltmarsh extent for six regions across Great Britain (1846-2016) 2019-09-18 publication 2019-05-15 creation https://catalogue.ceh.ac.uk/id/03b62fd0-41e2-4355-9a06-1697117f0717 10.5285/03b62fd0-41e2-4355-9a06-1697117f0717 doi: Ladd, C.J.T., Duggan-Edwards, M.F., Bouma, T.J., Pagès, J.F., Skov, M.W. (2019). Change in saltmarsh extent for six regions across Great Britain (1846-2016). NERC Environmental Information Data Centre 10.5285/03b62fd0-41e2-4355-9a06-1697117f0717 Data are presented showing change in saltmarsh extent along 25 estuaries/embayments in six regions across Great Britain, between 1846 and 2016. Data were captured from maps and aerial photographs. Marsh extent was delineated a scale of 1:7,500 by placing vertices every 5 m along the marsh edge. Error introduced from: (i) inaccuracies in the basemap used to georeference maps and aerial photographs; (ii) the georeferencing procedure itself; (iii) the interpreter when placing vertices on the marsh edge; and (iv) map and photo distortions that occurred prior to digitisation were calculated and used to estimate the root mean square error (RMSE) in areal extent of each marsh complex. Measures of marsh extent were only recorded if maps and aerial photographs were available for the entire estuary/embayment. Data was collected as part of a study on the large-scale, long-term trends and causes of lateral saltmarsh change. The data was used in the analysis for Ladd et al. (2019). C. Ladd and M.F. Duggan-Edwards carried out the collection and processing of the saltmarsh extent data. All authors contributed to the interpretation of the data. The work was carried out under the NERC programme - Carbon Storage in Intertidal Environment (C-SIDE), NERC grant reference NE/R010846/1. Full details about this dataset can be found at https://doi.org/10.5285/03b62fd0-41e2-4355-9a06-1697117f0717 Ladd, C. Bangor University c.ladd@bangor.ac.uk pointOfContact Ladd, C.J.T. Bangor University c.ladd@bangor.ac.uk https://orcid.org/0000-0001-5437-6474 ORCID record ORCID is an open, non-profit, community-driven effort to create and maintain a registry of unique researcher identifiers and a transparent method of linking research activities and outputs to these identifiers. information author Duggan-Edwards, M.F. Bangor University m.duggan-edwards@bangor.ac.uk https://orcid.org/0000-0002-5261-1749 ORCID record ORCID is an open, non-profit, community-driven effort to create and maintain a registry of unique researcher identifiers and a transparent method of linking research activities and outputs to these identifiers. information author Bouma, T.J. Royal Netherlands Institute for Sea Research Tjeerd.Bouma@nioz.nl https://orcid.org/0000-0001-7824-7546 ORCID record ORCID is an open, non-profit, community-driven effort to create and maintain a registry of unique researcher identifiers and a transparent method of linking research activities and outputs to these identifiers. information author Pagès, J.F. Centre d’Estudis Avançats de Blanes j.pages@ub.edu https://orcid.org/0000-0001-9346-8312 ORCID record ORCID is an open, non-profit, community-driven effort to create and maintain a registry of unique researcher identifiers and a transparent method of linking research activities and outputs to these identifiers. information author Skov, M.W. Bangor University m.w.skov@bangor.ac.uk https://orcid.org/0000-0002-7204-3865 ORCID record ORCID is an open, non-profit, community-driven effort to create and maintain a registry of unique researcher identifiers and a transparent method of linking research activities and outputs to these identifiers. information author NERC Environmental Information Data Centre info@eidc.ac.uk publisher NERC EDS Environmental Information Data Centre info@eidc.ac.uk custodian notPlanned Habitats and Biotopes theme GEMET - INSPIRE themes, version 1.0 2008-06-01 publication salt marsh GEMET - Concepts, version 4.1.3 2019-01-28 creation Carbon Storage in Intertidal Environment (C-SIDE) otherRestrictions no limitations otherRestrictions © Bangor University otherRestrictions © Royal Netherlands Institute for Sea Research otherRestrictions © Centre d’Estudis Avançats de Blanes otherRestrictions This resource is available under the terms of the Open Government Licence otherRestrictions If you reuse this data, you should cite: Ladd, C.J.T., Duggan-Edwards, M.F., Bouma, T.J., Pagès, J.F., Skov, M.W. (2019). Change in saltmarsh extent for six regions across Great Britain (1846-2016). NERC Environmental Information Data Centre https://doi.org/10.5285/03b62fd0-41e2-4355-9a06-1697117f0717 vector 5 English utf8 biota environment 1846-06-01 2016-05-26 -5.747 2.032 49.807 55.298 Shapefile NERC EDS Environmental Information Data Centre info@eidc.ac.uk distributor https://data-package.ceh.ac.uk/data/03b62fd0-41e2-4355-9a06-1697117f0717 Download the data Download a copy of this data download https://data-package.ceh.ac.uk/sd/03b62fd0-41e2-4355-9a06-1697117f0717.zip Supporting information Supporting information available to assist in re-use of this dataset information dataset dataset 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 2010-12-08 The aerial extent change in saltmarsh extent across Great Britain came into existence by using Ordnance Survey (OS) maps and aerial photographs to delineate marsh extent for each estuary.. Marsh extent was delineated in ArcGIS 10.6 at a scale of 1:7,500 by placing vertices every 5m along the marsh edge. A Root Mean Square Error (RMSE) term (in meters) was calculated for each marsh complex by assessing error introduced by: (i) inaccuracies in the basemap used to georeference maps and aerial photographs; (ii) the georeferencing procedure itself; (iii) the interpreter when placing vertices on the marsh edge; and (iv) map and photo distortions that occurred prior to digitisation. To qualitatively assess whether the vectorised layer could be considered accurate, the most recent digitised marsh extent was compared against national marsh extent layers to ensure general agreement. Literature searches were also done to verify whether observations of significant change in marsh extent were reliable, or whether errors introduced by map surveyors on the location of the marsh edge likely explain the differences.