Identification

Title

Change in saltmarsh extent for six regions across Great Britain (1846-2016)

Abstract

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

Resource type

dataset

Resource locator

https://data-package.ceh.ac.uk/data/03b62fd0-41e2-4355-9a06-1697117f0717

name: Download the data

description: Download a copy of this data

function: download

https://data-package.ceh.ac.uk/sd/03b62fd0-41e2-4355-9a06-1697117f0717.zip

name: Supporting information

description: Supporting information available to assist in re-use of this dataset

function: information

Unique resource identifier

code

https://catalogue.ceh.ac.uk/id/03b62fd0-41e2-4355-9a06-1697117f0717

codeSpace

doi:

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

biota

environment

Keywords

Keyword set

keyword value

Habitats and Biotopes

originating controlled vocabulary

title

GEMET - INSPIRE themes, version 1.0

reference date

date type

publication

effective date

2008-06-01

Keyword set

keyword value

Saltmarsh

Salt Marsh

areal extent

Historical

Geographic location

West bounding longitude

-5.747

East bounding longitude

2.032

North bounding latitude

55.298

South bounding latitude

49.807

Temporal reference

Temporal extent

Begin position

1846-06-01

End position

2016-05-26

Dataset reference date

date type

publication

effective date

2019-09-18

date type

creation

effective date

2019-05-15

Frequency of update

notPlanned

Quality and validity

Lineage

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.

Conformity

Conformity report

specification

title

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

reference date

date type

publication

effective date

2010-12-08

degree

explanation

Data format

name of format

Shapefile

version of format

Constraints related to access and use

Constraint set

Limitations on public access

Constraint set

Limitations on public access

Constraint set

Limitations on public access

Constraint set

Limitations on public access

Constraint set

Limitations on public access

Constraint set

Limitations on public access

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

custodian

Metadata on metadata

Metadata point of contact

organisation name

Environmental Information Data Centre

full postal address

Lancaster Environment Centre, Library Avenue, Bailrigg

Lancaster

LA1 4AP

email address

info@eidc.ac.uk

responsible party role

pointOfContact

Metadata date

2023-04-27T19:03:59

Metadata language

eng