National Flood Hazard Maps - Climate Change
Mapiau Perygl Llifogydd Cenedlaethol - Newid Hinsawdd

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The National Flood Hazard Climate Change maps are based on generalised modelling only. These maps use the same base information as the Present Day Hazard Maps, but include an allowance for Climate Change (2120). These maps have no official status for Planning or Insurance purposes, therefore the public and professionals are advised to use the information contained within the Flood Risk Assessment Wales Map, the Development Advice Map / Flood Map for planning (as appropriate) for these purposes as these will be more up-to-date and incorporate improved modelling information.


The National Flood Hazard Map for Climate Change have been created for 3 sources of flooding, namely,

1. Flooding from Rivers

2. Flooding from the Sea

3. Flooding from Surface Water & Small Watercourses


The Maps show flood depth, velocity (speed), hazard and extent for High, Medium and Low risk scenarios with raised flood defences.


For Rivers and Surface Water & Small Watercourses, High risk is up to 1 in 30year plus climate change uplift (CC); Medium risk is between 1 in 30 plus CC and 1 in 100year plus CC and Low risk is between 1 in 100 year plus CC and 1 in 1,000year plus CC Annual Exceedance Probability (AEP).


For the Sea, High risk is up to 1 in 30 year plus CC; Medium risk is between 1 in 30 plus CC to 1 in 200 year plus CC; and Low risk 1 in 200 year plus CC to 1 in 1000 year plus CC.


The Climate Change uplift values use the “Central” estimate for the year 2120 from the Welsh Government guidance available at the time of modelling (2018).

Mae'r mapiau Perygl Llifogydd Cenedlaethol Newid Hinsawdd yn seiliedig ar fodelu cyffredinol yn unig. Mae'r mapiau hyn yn defnyddio'r un wybodaeth sylfaenol â Mapiau Peryglon Heddiw, ond maent yn caniatáu ar gyfer Newid Hinsawdd (2120). Nid oes gan y mapiau hyn unrhyw statws swyddogol at ddibenion Cynllunio neu Yswiriant, felly cynghorir y cyhoedd a gweithwyr proffesiynol i ddefnyddio’r wybodaeth sydd wedi’i chynnwys ym Map Asesiad Perygl Llifogydd Cymru, y Map Cyngor Datblygu / Map Llifogydd ar gyfer cynllunio (fel y bo’n briodol) at y dibenion hyn gan y bydd y rhain yn fwy diweddar ac yn ymgorffori gwell gwybodaeth ar gyfer modelu.


Mae’r Map Peryglon Llifogydd Cenedlaethol ar gyfer Newid Hinsawdd wedi’i greu ar gyfer 3 ffynhonnell llifogydd, sef,

1. Llifogydd o afonydd

2. Llifogydd o'r môr

3. Llifogydd o ddŵr wyneb a chyrsiau dŵr bychain


Mae'r Mapiau'n dangos dyfnder, cyflymder (buanedd), perygl a maint llifogydd ar gyfer senarios risg uchel, canolig ac isel gydag amddiffynfeydd llifogydd uwch.


Ar gyfer afonydd a dŵr wyneb a chyrsiau dŵr bychain, risg uchel yw hyd at 1 mewn 30 mlynedd ynghyd ag ymgodiad newid hinsawdd (CC); Mae risg ganolig rhwng 1 mewn 30 ynghyd â CC ac 1 mewn 100 mlynedd a mwy o CC ac mae risg isel rhwng 1 mewn 100 mlynedd ynghyd ag CC ac 1 mewn 1,000 o flynyddoedd ynghyd â Thebygolrwydd Gormodiant Blynyddol (AEP) CC.


Ar gyfer y Môr, risg uchel yw hyd at 1 mewn 30 mlynedd ynghyd â CC; risg ganolig yw rhwng 1 mewn 30 plws CC i 1 mewn 200 mlynedd ynghyd â CC; a risg isel yw 1 mewn 200 mlynedd ynghyd â CC i 1 mewn 1000 o flynyddoedd ynghyd â CC.


Mae gwerthoedd ymgodiad Newid Hinsawdd yn defnyddio’r amcangyfrif “Canolog” ar gyfer y flwyddyn 2120 o ganllawiau Llywodraeth Cymru a oedd ar gael adeg y modelu (2018).

Identification

Dynodydd
Identifier
NRW_DS161288
Teitl Amgen
Alternative Title
  • Mapiau Perygl Llifogydd Cenedlaethol
  • National Flood Hazard Maps Climate Change.lyr
Laith Metadata
Metadata Language
English
Lineage

The datasets have been created as part of the Flood Risk Assessment Wales (FRAW) 2018 project. The modelling has been undertaken on the Environment Agency Integrated Height Model (EA IHM) 2016, with input rainfall and flow estimates from the Centre for Ecology & Hydrology (CEH). Sea level estimates have been taken from the Coastal Flood Boundary Project (CFB) 2018. Climate Change uplift values taken from the Welsh Government guidance available at the time of modelling (2018).
Additional Information

More information on the FRAW 2018 project can be found in the final project report.


JBA Consulting 2019. Flood Risk Assessment Wales Project Report. Unpublished report commissioned by Natural Resources Wales. 363 pp, Natural Resources Wales, Cardiff.
Dyddiad cyfeirnod y set ddata (Cyhoeddiad)
Dataset Reference Date (Publication)
2024-12-16

Temporal Extent

Begin date
2019-01-01
End date
2019-12-31
 
Categori pwnc
Topic category
  • Inland waters
    Inland waters
Perchennog
Owner
  Natural Resources Wales (NRW) -
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
Cychwynnwr
Originator
  JBA Consultancy -
JBA Consulting, 1 Belle Vue Square, Broughton Road, Skipton, BD23 1FJ
https://www.jbaconsulting.com/
 

Extent

Extent

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


 
 

Distribution

Dosbarthiad
Distribution

Fformat - Math a Disgrifiad
Format Type and Description
  • Geographic Information System ( Unknown )

Lleolwr Adnoddau
Resource Locator
Download Data ( WWW:LINK-1.0-http--link )
 

Quality

Ansawdd Data
Data quality

Cwmpas Ansawdd
Quality Scope
Dataset
Dataset
Cydymffurfiad
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

The datasets have been created as part of the Flood Risk Assessment Wales (FRAW) 2018 project. The modelling has been undertaken on the Environment Agency Integrated Height Model (EA IHM) 2016, with input rainfall and flow estimates from the Centre for Ecology & Hydrology (CEH). Sea level estimates have been taken from the Coastal Flood Boundary Project (CFB) 2018. Climate Change uplift values taken from the Welsh Government guidance available at the time of modelling (2018).
 

Keywords

Allweddair
Keywords

GEMET - INSPIRE themes, version 1.0
Math
Type
Theme
Theme

Dyfyniad
Citation

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

Allweddair
Keywords

NRW Thesaurus
  • flood risk
  • flood hazard
  • floods (flooding)
Math
Type
Theme
Theme

Dyfyniad
Citation

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

Spatial Reference System

Code
British National Grid (EPSG::27700)
 

Content

Gwybodaeth Cynnwys
Content Information

Proffil CNC
NRW Profile

Elfennau CNC
Custom Elements

NRW Related Title

Risk of Flooding from Surface Water
 

Constraints

Constraints

Limitations on Public Access and Use

Math o Gyfyngiad
Restriction type
Other restrictions
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

Cyfyngiadau Defnyddio
Use constraints type
Other restrictions
Other restrictions
Other constraints

© CNC/NRW. Some features of this information are based on digital spatial data licensed from the UK Centre for Ecology and Hydrology © UKCEH, © EA and Getmapping Plc and Bluesky International Limited (2015). Defra, Met Office and DARD Rivers Agency © Crown copyright. © Cranfield University. © James Hutton Institute. Contains OS data © Crown copyright and database right. Land and Property Services © Crown copyright and database right. 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

Contains Natural Resources Wales information © Natural Resources Wales and database right. All rights reserved. Some features of this information are based on digital spatial data licensed from the UK Centre for Ecology & Hydrology © UKCEH, the Environment Agency © EA and Getmapping Plc and Bluesky International Limited [2015]. Defra, Met Office and DARD Rivers Agency © Crown copyright. © Cranfield University. © James Hutton Institute. Contains OS data © Crown copyright and database right. Land & Property Services © Crown copyright and database right.
 

Licence

Other constraints
Open Government Licence
 
 
 

Metadata

Metadata

Dynodydd Ffeil
File Identifier
4f4c4942-4343-5764-6473-313631323838 XML
Laith Metadata
Metadata Language
English
Math o adnodd
Resource type
Dataset
Dataset
Dyddiad Metadata
Metadata Date
2026-10-15T12:32:09.461Z
Enw Safonol Metadata
Metadata Standard Name
NRW
Fersiwn Metadata
Metadata Standard Version

1.0

Pwynt Cyswllt
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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