f1cd5e33-2633-4304-bbc2-b8d34711d902 English ISO/IEC 8859-1 (also known as Latin 1) dataset dataset NERC EDS Environmental Information Data Centre Lancaster Environment Centre, Library Avenue, Bailrigg Lancaster LA1 4AP UK info@eidc.ac.uk https://eidc.ac.uk/ EIDC website The Environmental Information Data Centre (EIDC) is the UK's national data centre for terrestrial and freshwater sciences. information pointOfContact 2026-01-09T12:17:42 UK GEMINI 2.3 OSGB 1936 / British National Grid Integrated Hydrological Units of the United Kingdom: Groups 2015-02-03 publication 2014-08-20 creation 1425380901992 CEH:EIDC: https://catalogue.ceh.ac.uk/id/f1cd5e33-2633-4304-bbc2-b8d34711d902 10.5285/f1cd5e33-2633-4304-bbc2-b8d34711d902 doi: Kral, F., Fry, M., Dixon, H. (2015). Integrated Hydrological Units of the United Kingdom: Groups. NERC Environmental Information Data Centre 10.5285/f1cd5e33-2633-4304-bbc2-b8d34711d902 This dataset is part of Integrated Hydrological Units (IHU) of the UK, a set of geographical reference units for hydrological purposes including river flow measurement and hydrometric data collection. Groups represent the intermediate units of IHU in terms of spatial resolution. The most common size of a group is around 400 square kilometres. Each Group carries a name constructed from names of the major river flowing through the Group, the major river flowing into the Group, the major river into which the Group flows, and sometimes also from local county names. Each Group consists of one or more Section and Groups can be combined to form Hydrometric Areas without Coastline. Identifiers and attributes have been calculated so that direct upstream and direct downstream IHU units can be selected. This layer currently covers Great Britain only as no dataset with river geometries and names with suitable detail is available for Northern Ireland. Full details about this dataset can be found at https://doi.org/10.5285/f1cd5e33-2633-4304-bbc2-b8d34711d902 Fry, M. UK Centre for Ecology & Hydrology enquiries@ceh.ac.uk pointOfContact Centre for Ecology & Hydrology nrfa@ceh.ac.uk owner Kral, F. Centre for Ecology & Hydrology enquiries@ceh.ac.uk author Fry, M. Centre for Ecology & Hydrology enquiries@ceh.ac.uk https://orcid.org/0000-0003-1142-4039 ORCID record ORCID is an open, non-profit, community-driven effort to create and maintain a registry of unique researcher identifiers and a transparent method of linking research activities and outputs to these identifiers. information author Dixon, H. Centre for Ecology & Hydrology enquiries@ceh.ac.uk https://orcid.org/0000-0002-7415-063X ORCID record ORCID is an open, non-profit, community-driven effort to create and maintain a registry of unique researcher identifiers and a transparent method of linking research activities and outputs to these identifiers. information author NERC EDS Environmental Information Data Centre info@eidc.ac.uk custodian NERC Environmental Information Data Centre info@eidc.ac.uk publisher irregular New versions unlikely to be released more than annually. Hydrography theme GEMET - INSPIRE themes, version 1.0 2008-06-01 publication hydrology watershed catchment GEMET - Concepts, version 4.1.3 2019-01-28 creation United Kingdom England Wales Scotland GeoNames 2006-01-01 creation Hydrology Great Britain otherRestrictions Registration is required to access this data otherRestrictions Licence terms and conditions apply otherRestrictions If you reuse this data, you should cite: Kral, F., Fry, M., Dixon, H. (2015). Integrated Hydrological Units of the United Kingdom: Groups. NERC Environmental Information Data Centre https://doi.org/10.5285/f1cd5e33-2633-4304-bbc2-b8d34711d902 vector English utf8 inlandWaters 2014-08-20 -8.648 1.768 49.864 60.861 File geodatabase NERC EDS Environmental Information Data Centre info@eidc.ac.uk distributor https://data-package.ceh.ac.uk/data/f1cd5e33-2633-4304-bbc2-b8d34711d902 Download the data Download a copy of this data download https://data-package.ceh.ac.uk/sd/f1cd5e33-2633-4304-bbc2-b8d34711d902.zip Supporting information Supporting information available to assist in re-use of this datasets. information https://catalogue.ceh.ac.uk/maps/cca47088-8cdd-4d7a-86b4-90f0a1766364?request=getCapabilities&service=WMS Map view service This link returns a WMS GetCapabilities response in XML format dataset dataset 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 The main inputs for development of Integrated Hydrological Units (IHU) of the UK were data held by the Centre for Ecology & Hydrology. Specifically, the cumulative catchment area raster and outflow raster from the Integrated Hydrological Digital Terrain Model (IHDTM) [1]. The vast majority of the watercourse names come from the subset of CEH UK river centreline network enriched by names from Ordnance Survey 1:50K Gazetteer [2]. Some names were obtained from or verified using other readily available sources like OpenStreetMap (openstreetmap.org) and WikiPedia (wikipedia.org). Bespoke FORTRAN functions, part of the CEH Flood Estimation Handbook code set, were used for catchment delineation. These functions enable sensible interlocking catchments boundaries to be created for the whole IHDTM surface. The option that does not leave gaps between catchments was specified [1]. Except for the catchment delineation, ArcGIS was used as the main GIS platform. Custom Python code was developed to drive the whole process and to perform hierarchical and network tasks. The full name of each IHU Section was derived from three rivers defining the section: the largest (in terms of cumulative catchment area) inflowing river other than the main river in the Section, the main river in the Section, and the largest river flowing into the downstream Section. If no such inflows exist, words 'Source', 'Sea', or the name of the main river in the downstream Section are used as appropriate. A similar approach was adopted for IHU Group names, although group names were edited manually to a great extent to ensure they are simple and readily understood. [1] Morris, D.G. and Flavin, R.W. 1990. A Digital Terrain Model for Hydrology. Proc 4th Int. Symposium on Spatial Data Handling. Zurich, 1, 250-262. [2] Moore R V, Morris D G and Flavin R W, 1994. Sub-set of UK digital 1:50,000 scale river centreline network. NERC, Institute of Hydrology, Wallingford.