Mapping the Role of Coastal Habitats in Mitigating Flood Risk
This data resource contains four GIS layers and a MS Excel workbook that make up the deliverables associated with NRW evidence report 935.
The four GIS layers are: coastal units (Coastal_Units_25062025), dunes habitats per coastal unit (CU_Dunes_22052025), saltmarsh habitats per coastal unit (CU_Saltmarsh_22052025) and shingle habitats per coastal unit (CU_Shingle_29052025).
Coastal Units (CUs) were defined by grouping deliverables from a Coastal Squeeze project (Accommodation Spaces, their associated Assessment Units and Foreshore Areas) together. The coastal units were the unit of assessment for determining the flood risk benefit of coastal habitats around the Welsh coastline.
The sand dune, shingle, and saltmarsh habitats were clipped to each CU and their Functional Value assessed. These are provided in the relevant layers.
The excel file (NCA workbook of flood protection from coastal habitats in Wales_Final) provides a natural capital assessment of the various habitats, which feeds into the values in the coastal unit layer.
- Identification
- Extent
- Distribution
- Quality
- Keywords
- Spatial Reference System
- Content
- Constraints
- Maintenance
- Metadata
Identification
- Identifier
- NRW_DS161382
- Alternative Title
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- Flood risk benefits of coastal habitats
- Metadata Language
- English
- Lineage
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For detailed methods see NRW evidence report 935 “Spatial mapping of the role of coastal habitats in mitigating flood risk in Wales.”
For each Coastal Unit, the functional value of habitats was determined based on width and height (for dunes and shingle). The estimated length of the coastline fronted by each habitat and the total area of each habitat within the Coastal Unit were obtained and used to calculate an inferred width of each habitat within each Coastal Unit. Heights of the habitats were estimated using the Digital Terrain Model. These values are stored in the three habitat layers. The functional value was used to estimate a percentage reduction in flood damages that could be attributed to each habitat.
For each Coastal Unit, areas at high, medium and low risk from flooding from the sea in the present day were identified using the Flood Risk Assessment Wales (FRAW) data layer. The key assets (properties and infrastructure, agricultural land, road and rail) within each flood risk zone were identified. The CU deliverable also captures short-term erosion rates, overlap with designated areas, and the presence of a flood defence where applicable.
Also included in the CU are the central estimates of economic evaluation results detailed in eftec’s NCA Workbook deliverable. Data inputs:
• Coastal Squeeze deliverables: Assessment Unit line, Accommodation Space, Foreshore Area, Digital Terrain Model
• Habitat extents: Sand dune, Saltmarsh, Vegetated shingle, and Littoral coarse sediment extent
• Flood Risk Assessment Wales (FRAW) ( https://datamap.gov.wales/layergroups/inspire-nrw:FloodRiskAssessmentWales )
• National Receptor Dataset (NRD) 2023, NRW ( https://metadata.naturalresources.wales/geonetwork/srv/eng/catalog.search#/metadata/NRW_DS1257 21)
• Predictive Agricultural Land Classification (ALC) Map 2, Welsh Government ( https://datamap.gov.wales/layers/inspire-wg:wg_predictive_alc 2)
• OS Open Roads, Ordnance Survey ( https://osdatahub.os.uk/downloads/open/OpenRoads )
• Rail lines from OS Open Zoomstack, Ordnance Survey ( https://osdatahub.os.uk/downloads/open/OpenZoomstack )
• National Coastal Erosion Risk Management (NCERM) ( https://datamap.gov.wales/layergroups/geonode:nrw_ncerm )
- Additional Information
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Beynon-Davies, C. 2025. A review of the role of coastal and marine habitats in mitigating coastal erosion and flooding in Wales. NRW Evidence Report No: 922, 93pp, NRW, Cardiff.
Fairchild TP, Bennett WG, Smith G, Day B, Skov MW, Möller I, Beaumont N, Karunarathna H, Griffin JN. 2021. Coastal wetlands mitigate storm flooding and associated costs in estuaries. Environmental Research Letters (16) 074034.
- Dataset Reference Date (Creation)
- 2025-08-18
Temporal Extent
- Begin date
- 2025-06-01
- End date
- 2025-06-30
- Topic category
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- Environment
Extent
Extent
- Geographic Extent
- Wales (WLS)
))
Distribution
Distribution
- Format Type and Description
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Delimited
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Unknown
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Data available as an Excel file
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Geographic Information System
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Unknown
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ESRI Feature Class
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Documents
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Unknown
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NRW Evidence Report in word or pdf format
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Delimited
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Unknown
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Quality
Data quality
- Quality Scope
- Dataset
- Conformity
- 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
- Explanation
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This dataset has not been assessed for conformance to the referenced INSPIRE regulation.
- Degree
- false
- Lineage
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For detailed methods see NRW evidence report 935 “Spatial mapping of the role of coastal habitats in mitigating flood risk in Wales.”
For each Coastal Unit, the functional value of habitats was determined based on width and height (for dunes and shingle). The estimated length of the coastline fronted by each habitat and the total area of each habitat within the Coastal Unit were obtained and used to calculate an inferred width of each habitat within each Coastal Unit. Heights of the habitats were estimated using the Digital Terrain Model. These values are stored in the three habitat layers. The functional value was used to estimate a percentage reduction in flood damages that could be attributed to each habitat.
For each Coastal Unit, areas at high, medium and low risk from flooding from the sea in the present day were identified using the Flood Risk Assessment Wales (FRAW) data layer. The key assets (properties and infrastructure, agricultural land, road and rail) within each flood risk zone were identified. The CU deliverable also captures short-term erosion rates, overlap with designated areas, and the presence of a flood defence where applicable.
Also included in the CU are the central estimates of economic evaluation results detailed in eftec’s NCA Workbook deliverable. Data inputs:
• Coastal Squeeze deliverables: Assessment Unit line, Accommodation Space, Foreshore Area, Digital Terrain Model
• Habitat extents: Sand dune, Saltmarsh, Vegetated shingle, and Littoral coarse sediment extent
• Flood Risk Assessment Wales (FRAW) ( https://datamap.gov.wales/layergroups/inspire-nrw:FloodRiskAssessmentWales )
• National Receptor Dataset (NRD) 2023, NRW ( https://metadata.naturalresources.wales/geonetwork/srv/eng/catalog.search#/metadata/NRW_DS1257 21)
• Predictive Agricultural Land Classification (ALC) Map 2, Welsh Government ( https://datamap.gov.wales/layers/inspire-wg:wg_predictive_alc 2)
• OS Open Roads, Ordnance Survey ( https://osdatahub.os.uk/downloads/open/OpenRoads )
• Rail lines from OS Open Zoomstack, Ordnance Survey ( https://osdatahub.os.uk/downloads/open/OpenZoomstack )
• National Coastal Erosion Risk Management (NCERM) ( https://datamap.gov.wales/layergroups/geonode:nrw_ncerm )
Keywords
Keywords
- Type
- Theme
Citation
- Date (Publication)
- 2008-06-01
Keywords
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NRW Thesaurus
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- flood risk
- coastal habitats (see also specific habitat: saltmarsh,sanddune,maritime heath)
- sand dunes (sand-dunes) (dunes) (see also specifically named dunes)
- saltmarsh (salt-marsh) (salt marsh)
- Type
- Theme
Citation
- Date (Publication)
- 2026-03-04
Keywords
- Type
- Theme
Citation
- Date (Publication)
- 2024-06-19
Spatial Reference System
Content
Content Information
NRW Profile
Custom Elements
Constraints
Constraints
Limitations on Public Access and Use
- Restriction type
- Other restrictions
Access Constraints Text
- Other constraints
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The data is considered derived from Middlesex University London owned data and therefore has third party ownership associated with it. There may be access restrictions on the derived third party data use.
Use Constraints
- Use constraints type
- Other restrictions
- Other constraints
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© CNC/NRW. © Middlesex University, Flood Hazard Research Centre. © JNCC. © Crown Copyright: Welsh Government. Data may be re-used under provision and in line with the terms of a NRW licence.
Attribution Statement
- Other constraints
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Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved. © Middlesex University, Flood Hazard Research Centre. © JNCC © Crown copyright: Welsh Government.
Licence
- Other constraints
- NRW Conditional