Fluvial Audit of the Afon Tywi

  • English
  • wel
  • All

The Afon Tywi in Carmarthenshire is a large actively eroding river, designated as a Special Area of Conservation (SAC) for its migratory fish, and as a Site of Special Scientific Interest (SSSI) for various features including river habitat, river shingle invertebrates and little ringed plover. The river is unusually active in the middle reaches, sometimes moving as much as 50 m in a single year, and the various species for which the river is designated depend on the river remaining active. In order to inform current and future river management, a fluvial audit of the past and present geomorophology of the Afon Tywi was carried out. This consists of a detailed technical report including identification of the most active river sections based on historic maps, a timeline of the river indicating key events such as major floods, and maps showing the geomorphology and sediment character of the river. Advice is also provided on the future sustainable management of the Tywi as an active shingle river. This dataset consists of the results from the Fluvial Audit of the Afon Tywi which describes and spatially maps the past and present fluvial geomorphology of the Tywi catchment. The aim of this data capture was to: - Develop an understanding of the dynamic geomorphology of the Afon Tywi. Specific aims include: - Describe and map the fluvial geomorphology of the Tywi catchment past and present using a GIS system. - Interpret the data gathered in the context of past and present human activity, including a risk assessment of consented activities. - Provide advice on the future management of the Tywi SAC for use as a management and casework decision-making tool with regards to future bank reinforcement work, flood defence activities, aggregate extractions etc.

Identification

Dynodydd
Identifier
NRW_DS111562
Teitl Amgen
Alternative Title
  • Archwiliad o Afon Tywi
Laith Metadata
Metadata Language
English
Lineage

The project had numerous stages as follows: Stage 1: Catchment Overview - literature study and GIS analysis of the catchment characteristics. Stage 2: Hydrological Assessment. Stage 3: The Fluvial Audit - Map and aerial photograph-based assessment; Field-based assessment; Detailed survey of sediment character; Linking map, field-based and laboratory results; Geomorphic impact of floods; Assessing sediment stores on the Afon Tywi; Impacts of human activity (including information from questionnaire of riparian users); Detailed analysis of case-study reaches. Stage 4: Sensitivity assessment to help evaluate risk - Analysis of sediment balance at the points of gravel extraction; Strategy for assessing the impact of existing and potential gravel extraction. Stage 5: Sediment transport modelling. Stage 6: Risk assessment and management advice.
Dyddiad cyfeirnod y set ddata (Cyhoeddiad)
Dataset Reference Date (Publication)
1953-12-31
Perchennog
Owner
  Natural Resources Wales (NRW)
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
Cychwynnwr
Originator
  Geography and Environmental Management Research Unit, University of Gloucestershire
 

Extent

Extent

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


 
 

Distribution

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

    Specification

    [A] Report: Adobe Portable Document Format versions of Volume 1 and 3 of project report. Paper copy of all volumes- Volume 1: Technical Report; Volume 2: Maps Report; Volume 3: Short report for use by river managers. [B] GIS Data: MapInfo tables- Species data, Bank protection, Gravel extraction, Channel line

 

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
Degree
false
Lineage

The project had numerous stages as follows: Stage 1: Catchment Overview - literature study and GIS analysis of the catchment characteristics. Stage 2: Hydrological Assessment. Stage 3: The Fluvial Audit - Map and aerial photograph-based assessment; Field-based assessment; Detailed survey of sediment character; Linking map, field-based and laboratory results; Geomorphic impact of floods; Assessing sediment stores on the Afon Tywi; Impacts of human activity (including information from questionnaire of riparian users); Detailed analysis of case-study reaches. Stage 4: Sensitivity assessment to help evaluate risk - Analysis of sediment balance at the points of gravel extraction; Strategy for assessing the impact of existing and potential gravel extraction. Stage 5: Sediment transport modelling. Stage 6: Risk assessment and management advice.
 

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
  • fluvial
  • fluvial geomorphology
  • fluvial processes
  • rivers (see also specific river names)
  • river Tywi (afon Tywi)
  • Upper Reaches of Afon Tywi
  • Special Areas of Conservation (SAC) (see also Candidate Special Areas of Conservation cSAC)
  • SSSI (Sites of Special Scientific Interest)
  • geomorphology
Math
Type
Theme
Theme

Dyfyniad
Citation

Dyddiad (Cyhoeddiad)
Date (Publication)
2023-12-31
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

A fluvial audit of the Afon Tywi : Volume 1 : technical report
NRW Related Title

A fluvial audit of the Afon Tywi : Volume 2 : map volume
NRW Related Title

A fluvial audit of the Afon Tywi : Volume 2 : map volume (addendum revised figure 16d)
NRW Related Title

A fluvial audit of the Afon Tywi : Volume 3 : summary report
 

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

This dataset contains 'simple derived data' which is jointly owned by NRW and the Ordnance Survey in the form of river bank GIS layers (erosion, bank protection etc). NRW may release, publish or disseminate this dataset freely, providing recipients are made aware of use restrictions (see below). Data not derived from OS products have no access or use restrictions. Third party recipients may reproduce, disseminate and re-use this data free of charge in any format or medium, provided they do so accurately, acknowledging both the source and NRW's copyright, and do not use it in a misleading context. To avoid using old information, we recommend that the latest version is obtained from the original source.
 

Use Constraints

Cyfyngiadau Defnyddio
Use constraints type
Other restrictions
Other restrictions
Other constraints

Third parties seeking to re-use this data require a OS Derived Data Licence issued by NRW. It allows re-use, reproduction and dissemination in any format or medium but only for non-commercial purposes, according to the terms and conditions of the Licence. Those seeking commercial re-use require a commercial licence available from the OS.
 
 
 

Metadata

Metadata

Dynodydd Ffeil
File Identifier
4f4c4942-4343-5764-6473-313131353632 XML
Laith Metadata
Metadata Language
English
Parent Identifier
Fluvial Audits of Welsh River Systems

NRW_DS101833
Math o adnodd
Resource type
Dataset
Dataset
Dyddiad Metadata
Metadata Date
2024-05-30T15:36:15.999Z
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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