4f4c4942-4343-5764-6473-313234373834 English NRW_DS124799 Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en 2026-10-08T14:34:12.585Z NRW 1.0 wel utf8 British National Grid (EPSG::27700) CuRVe Connectivity River Modifications CuRVe Connectivity River Modifications Cysylltedd CuRVe: Addasiadau i Afonydd 2020-04-27 NRW_DS124784 http://naturalresources.wales/ This dataset provides a measure of resilience associated with river connectivity by assessing the extent of physical modifications and hard engineering affecting river systems within each reporting square. The resilience values are derived from information on modified water bodies and known artificial barriers that may reduce the ability of rivers to function as ecological corridors. The dataset combines evidence from Water Framework Directive (WFD) assessments and a national dataset of hydropower opportunities to produce a relative resilience score ranging from 0 to 100, where lower scores indicate a greater potential impact on river connectivity. This dataset provides a measure of resilience associated with river connectivity by assessing the extent of physical modifications and hard engineering affecting river systems within each reporting square. The resilience values are derived from information on modified water bodies and known artificial barriers that may reduce the ability of rivers to function as ecological corridors. The dataset combines evidence from Water Framework Directive (WFD) assessments and a national dataset of hydropower opportunities to produce a relative resilience score ranging from 0 to 100, where lower scores indicate a greater potential impact on river connectivity. Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Environment Systems Ltd 8G Vefn Llan Science Park, Aberystwyth, Ceredigion, SY23 3AH, Wales enquiries@envsys.co.uk http://www.envsys.co.uk/ Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Land cover GEMET - INSPIRE themes, version 1.0 2008-06-01 geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme ecological connectivity NRW Thesaurus 2026-08-27 geonetwork.thesaurus.local.theme.converted_nrw-keywords Biodiversity IPSV Subjects List 2020-11-18 geonetwork.thesaurus.external.theme.subjects There are no access restrictions on this data. NRW may release, publish or disseminate it freely. no limitations © CNC/NRW Data may be re-used under the terms of the Open Government Licence providing it is done so, acknowledging both the source and NRW's copyright. It is the recipient's responsibility to ensure the data is fit for the intended purpose. Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved. Contains Ordnance Survey Data. Ordnance Survey Licence number AC0000849444. Crown Copyright and Database Right. Contains data supplied by Natural Environment Research Council. Open Government Licence 1000 English environment SeaVoX Vertical Co-ordinate Coverages 2021-01-06 Wales (WLS) -5.777741 -2.608865 51.240829 53.513067 2020-03-01 2020-04-27 Naumann, E.-K., Medcalf, K., 2020. Current relative value (CuRVe) map atlas for ecosystem resilience in Wales. NRW Natural Resources Wales report series, Report No: 415, 88pp, Publisher, Place of publication. Current Relative Value (CuRVe) Map Atlas for Ecosystem Resilience in Wales Geographic Information System Arcmap feature class 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 2010-12-08 This dataset has not been assessed for conformance to the referenced INSPIRE regulation. false The dataset was produced using two primary data sources: Water Framework Directive (WFD) waterbody assessments and the DEFRA hydropower opportunities dataset. River waterbody catchments identified within the WFD Reasons for Not Achieving Good Status (RNAG) dataset as having confirmed or probable physical modifications were classified as affected by hard engineering and assigned a low resilience value. Catchments identified as Heavily Modified Water Bodies (HMWBs) were also included in this category. This created an initial binary assessment, assigning a resilience value of 0 to modified catchments and 100 to catchments with no recorded physical modification. As this approach was considered insufficiently representative of local conditions, particularly where downstream barriers influenced the status of upstream catchments, a second analysis was undertaken using the DEFRA hydropower opportunities dataset. Known locations of artificial barriers, such as weirs, were extracted and assessed according to their ecological sensitivity classification. Barriers classified as having high ecological sensitivity were assigned a score of 3, moderate sensitivity a score of 2, and low sensitivity a score of 1. Scores for all barriers within each reporting square were summed to generate a cumulative risk score. The resulting risk scores were inverted and normalised to a relative scale of 0 to 100 to generate resilience values, with higher values representing lower levels of connectivity pressure from artificial barriers. The resilience values derived from the WFD physical modification assessment and the DEFRA barrier analysis were then averaged to produce the final river connectivity resilience score for each reporting square. Full details of the methodology are provided in the associated project documentation and technical report. The dataset was produced using two primary data sources: Water Framework Directive (WFD) waterbody assessments and the DEFRA hydropower opportunities dataset. River waterbody catchments identified within the WFD Reasons for Not Achieving Good Status (RNAG) dataset as having confirmed or probable physical modifications were classified as affected by hard engineering and assigned a low resilience value. Catchments identified as Heavily Modified Water Bodies (HMWBs) were also included in this category. This created an initial binary assessment, assigning a resilience value of 0 to modified catchments and 100 to catchments with no recorded physical modification. As this approach was considered insufficiently representative of local conditions, particularly where downstream barriers influenced the status of upstream catchments, a second analysis was undertaken using the DEFRA hydropower opportunities dataset. Known locations of artificial barriers, such as weirs, were extracted and assessed according to their ecological sensitivity classification. Barriers classified as having high ecological sensitivity were assigned a score of 3, moderate sensitivity a score of 2, and low sensitivity a score of 1. Scores for all barriers within each reporting square were summed to generate a cumulative risk score. The resulting risk scores were inverted and normalised to a relative scale of 0 to 100 to generate resilience values, with higher values representing lower levels of connectivity pressure from artificial barriers. The resilience values derived from the WFD physical modification assessment and the DEFRA barrier analysis were then averaged to produce the final river connectivity resilience score for each reporting square. Full details of the methodology are provided in the associated project documentation and technical report.