WINS Urban Green Infrastructure: Demand for Urban Greenspace - Risk of Pluvial Flooding

This dataset was created for the Welsh Information for Nature-based Solutions (WINS) project (previously known as SCCAN) to identify opportunities for land management interventions that enhance ecosystem service delivery across a range of key policy areas. An accompanying User Guide is available to support the use of these datasets, and a full list of source datasets and data limitations can be found in the project technical report.


This dataset comprises two maps relating to pluvial flood risk and demand for natural flood management (NFM) interventions.


This dataset was created for the Welsh Information for Nature-based Solutions (WINS) project (previously known as SCCAN) to identify opportunities for land management interventions that enhance ecosystem service delivery across a range of key policy areas. An accompanying User Guide is available to support the use of these datasets, and a full list of source datasets and data limitations can be found in the project technical report.


This dataset comprises two maps relating to pluvial flooding. The first map shows the risk of standing water accumulation during heavy rainfall and the risk of strong overland flow, using separate colour ramps ranging from green to purple, with purple indicating the highest level of risk. Distinguishing between standing water and overland flow can help target interventions, as areas of overland flow may indicate the source of water contributing to downstream surface water flooding.


The second map shows demand for intervention based on population density and the Welsh Index of Multiple Deprivation (WIMD), displayed on a gradient from light to dark brown, with darker areas representing higher demand. A semi-transparent purple overlay highlights areas at the highest risk of pluvial flooding, enabling direct spatial comparison between flood risk and demand.

Identification

Identifier
NRW_DS121714
Alternative Title
  • SCCAN Urban Green Infrastructure: Demand for Urban Greenspace - Risk of Pluvial Flooding
Metadata Language
English
Lineage

To create this dataset, a Digital Surface Model (DSM) for Wales was derived from the NextMap Digital Terrain Model (DTM) and OS MasterMap data. Average building and feature heights were assigned to relevant MasterMap features and added to the DTM to produce the DSM.


The hydrology of the resulting DSM was analysed using SCIMAP (Durham University, 2016). Although SCIMAP was originally developed to model erosion risk, one of its intermediate outputs, the Network Index (connectivity), can also be used to indicate potential urban pluvial flood risk when applied to a DSM. The Network Index describes the likelihood of a parcel of land transferring material, in this case water, to another location. Areas with particularly high Network Index values were identified as being at greater risk of pluvial flooding.


To distinguish between areas susceptible to standing water and those susceptible to overland flow, slope data were used. Areas with slopes of less than 3° were classified as being at risk of standing water accumulation, while areas with steeper slopes were classified as being at risk of overland flow.


Demand for intervention was assessed using population density and the Welsh Index of Multiple Deprivation (WIMD). Population density, derived from census data, was classified into five categories using Jenks Natural Breaks. The two highest population density classes were assigned high priority, while the middle class was assigned moderate priority. WIMD data were classified using the categories published on the WIMD website. The two most deprived categories (ranks 1 to 382) were assigned high priority, while the next category (ranks 383 to 573) was assigned moderate priority.


This dataset was produced for NRW by Environment Systems Ltd.
Additional Information

Data gaps and limitations: For urban areas, the distinction between streets and buildings becomes increasingly important. As a result, a resolution finer than the 10 m pixel size used for the strategic-scale mapping undertaken for this project may be desirable. Urban drainage systems have not been considered in this mapping, which may result in the overestimation of standing water risk in some areas.
Dataset Reference Date (Publication)
2018-04-01

Temporal Extent

Begin date
2017-09-01
End date
2018-04-01
 
Topic category
  • Planning cadastre
  • Society
  • Farming
  • Biota
  • Geoscientific information
  • Climatology, meteorology, atmosphere
  • Environment
  • Elevation
  • Imagery base maps earth cover
  • Inland waters
Owner
  Natural Resources Wales (NRW) -
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
Originator
  Natural Resources Wales (NRW) -
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
 

Extent

Extent

Geographic Extent
Wales (WLS)
N
W
E
S
Map representing the geographic extent of the dataset


 
 

Distribution

Format Type and Description
  • Geographic Information System ( )

    Specification

    ESRI Feature Class

 

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

This dataset has not been assessed for conformance to the referenced INSPIRE regulation.
Degree
false
Lineage

To create this dataset, a Digital Surface Model (DSM) for Wales was derived from the NextMap Digital Terrain Model (DTM) and OS MasterMap data. Average building and feature heights were assigned to relevant MasterMap features and added to the DTM to produce the DSM.


The hydrology of the resulting DSM was analysed using SCIMAP (Durham University, 2016). Although SCIMAP was originally developed to model erosion risk, one of its intermediate outputs, the Network Index (connectivity), can also be used to indicate potential urban pluvial flood risk when applied to a DSM. The Network Index describes the likelihood of a parcel of land transferring material, in this case water, to another location. Areas with particularly high Network Index values were identified as being at greater risk of pluvial flooding.


To distinguish between areas susceptible to standing water and those susceptible to overland flow, slope data were used. Areas with slopes of less than 3° were classified as being at risk of standing water accumulation, while areas with steeper slopes were classified as being at risk of overland flow.


Demand for intervention was assessed using population density and the Welsh Index of Multiple Deprivation (WIMD). Population density, derived from census data, was classified into five categories using Jenks Natural Breaks. The two highest population density classes were assigned high priority, while the middle class was assigned moderate priority. WIMD data were classified using the categories published on the WIMD website. The two most deprived categories (ranks 1 to 382) were assigned high priority, while the next category (ranks 383 to 573) was assigned moderate priority.


This dataset was produced for NRW by Environment Systems Ltd.
 

Keywords

Keywords

GEMET - INSPIRE themes, version 1.0
Type
Theme

Citation

Date (Publication)
2008-06-01
Code
geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme

Keywords

NRW Thesaurus
  • Area Statement
  • SoNaRR
Type
Theme

Citation

Date (Publication)
2026-08-27
Code
geonetwork.thesaurus.local.theme.converted_nrw-keywords

Keywords

NRW SMNR Keywords
  • Ecosystem Services (SMNR)
  • Sustainable Management of Natural Resources (SMNR)
Type
Theme

Citation

Date (Publication)
2024-06-26
Code
geonetwork.thesaurus.local.theme.converted_nrw-smnr-keywords
 

Spatial Reference System

Code
British National Grid (EPSG::27700)
 

Content

Content Information

NRW Profile

Custom Elements

 

Constraints

Constraints

Limitations on Public Access and Use

Restriction type
Other restrictions
 

Access Constraints Directive

Limitations
no limitations
 

Access Constraints Text

Other constraints

There are no access restrictions on this data. NRW may release, publish or disseminate it freely.
 

Use Constraints

Use constraints type
Other restrictions
Other constraints

© CNC/NRW All rights Reserved. © Office for National Statistics (ONS). Data may be re-used under the terms of the Open Government Licence providing it is done so, acknowledging both the source and copyright of the owners. It is the recipient's responsibility to ensure the data is fit for the intended purpose.
 

Attribution Statement

Other constraints

Seilwaith Gwyrdd Trefol: - Galw am Fannau Gwyrdd Trefol - Perygl o Lifogydd Glawol
 

Licence

Other constraints
Open Government Licence
 
 
 

Metadata

Metadata

File Identifier
4f4c4942-4343-5764-6473-313231373134 XML
Metadata Language
English
Parent Identifier
WINS Area Statement Opportunity Maps

NRW_DS121668
Resource type
Dataset
Metadata Date
2026-09-30T14:01:56.834Z
Metadata Standard Name
NRW
Metadata Standard Version

1.0

pointOfContact
  Natural Resources Wales (NRW) -
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
 
 

Publishing Body

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