Identification

Title

MMO1065 Terrain Ruggedness Index of the South Plan area

Abstract

This raster represents the Terrain Ruggedness Index (TRI) of the south plan area, as part of the exploritary work in the MMO1065 Enhancing our understanding of Seabed Habitats and Topographic Features project. Using updated digital terrain models, a TRI was created and used as the method to determine the ruggedness of the seabed.

Resource type

dataset

Resource locator

http://environment.data.gov.uk/ds/catalogue/#/bf97a232051726a1ec83c6b832904ff4

description: A link to the web service or dataset

http://environment.data.gov.uk/ds/catalogue/#/catalogue

description: A link to the general host site

Unique resource identifier

code

MMO500009

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

urn:ogc:def:crs:EPSG::4258

Classification of spatial data and services

Topic category

elevation

inlandWaters

Keywords

Keyword set

keyword value

Keyword set

keyword value

originating controlled vocabulary

title

reference date

date type

revision

effective date

2008-01-06

Keyword set

keyword value

originating controlled vocabulary

title

reference date

date type

revision

effective date

2009-11-16

Geographic location

West bounding longitude

-4.0589

East bounding longitude

2.0599

North bounding latitude

51.7124

South bounding latitude

49.3232

Extent

Extent group

authority code

title

reference date

date type

creation

effective date

1954-01-01

code identifying the extent

Bristol Channel

Extent group

authority code

title

reference date

date type

creation

effective date

1954-01-01

code identifying the extent

English Channel

Extent group

authority code

title

reference date

date type

creation

effective date

1954-01-01

code identifying the extent

North Sea

Extent group

authority code

title

reference date

date type

creation

effective date

2014-05-16

code identifying the extent

VIIf

Extent group

authority code

title

reference date

date type

creation

effective date

2014-05-16

code identifying the extent

IVc

Extent group

authority code

title

reference date

date type

creation

effective date

2014-05-16

code identifying the extent

VIIe

Extent group

authority code

title

reference date

date type

creation

effective date

2014-05-16

code identifying the extent

VIId

Temporal reference

Temporal extent

Begin position

2014-04-22

End position

2016-08-22

Dataset reference date

date type

publication

effective date

2014-04-22

date type

creation

effective date

2014-04-22

date type

revision

effective date

2014-04-22

Frequency of update

asNeeded

Quality and validity

Lineage

There are several mathematical approaches to calculating the ruggedness of a surface, all of which are based on the distribution or variations of height values in a given data sample. The method used in the MMO1065 project was a Terrain Ruggedness Index (TRI) mainly because it was developed for bathymetry-based analysis. In this approach, the TRI value is calculated by comparing the bathymetry value of a central pixel with the values of its 8 neighbours. The absolute differences between the value of the central pixel and the values of its neighbours are summed and then divided by 8 to calculate the TRI for the central pixel. A TRI score of 0 would indicate a completely flat surface; the bigger the number the more rugged the surface. To calibrate the TRI to produce a new hard/soft substrate classification system, the TRI results were assessed against ground truth data from both nautical charts from the UKHO and sediment and hard surface samples provided by BGS. TRI values for the bathymetry grid varied between 0 and 17.16, with a mean value of 0.19. By comparison a TRI value of 1 would indicate that a given cell was 1 m higher or lower than all its neighbouring cells. In the context of the Defra DEM, a TRI of 1 would mean a change in height of the seabed of about 4% between grid cells The TRI, created using the GDALDEM TRI algorithm, uses the method introduced by Valentine et al. (2004) that was an adaptation of the method developed by Riley et al. (1999) specifically for bathymetric analysis of the seabed. The algorithm was then applied for seafloor habitat mapping by Wilson et al. (2007).

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Open Government Licence. Acknowledgement of Marine Management Organisation as source is required.

Constraint set

Limitations on public access

No limitations on access, however copyright should be used at all times.

Responsible organisations

Responsible party

contact position

Data/GIS Officer

organisation name

Marine Management Organisation

email address

dkm@marinemanagement.org.uk

responsible party role

originator

Responsible party

contact position

Data/GIS Officer

organisation name

Marine Management Organisation

email address

dkm@marinemanagement.org.uk

responsible party role

custodian

Metadata on metadata

Metadata point of contact

contact position

Data/GIS Officer

organisation name

Marine Management Organisation

email address

dkm@marinemanagement.org.uk

responsible party role

pointOfContact

Metadata date

2016-08-22

Metadata language