https://ckan.publishing.service.gov.uk/feeds/custom.atom?resource-type=datasetdata.gov.uk - Custom query2024-03-28T14:49:08.242513+00:00dgupython-feedgenRecently created or updated datasets on data.gov.uk. Custom query: '1m DTM'https://ckan.publishing.service.gov.uk/dataset/6fcb6a54-cf78-46ec-9c1a-ffb5dec76ad7Digital elevation models and bathymetry data of Tsho Rolpa glacier lake, Nepal, 20192023-05-03T20:11:30.573698+00:003D digital elevation models of Tsho Rolpa glacier lake, Nepal, generated from unmanned aerial vehicle (UAV) imagery, with a spatial resolution of 10 centimetres. It is combined with bathymetry data so that both the lakebed elevation (DTM) and the lake surface elevation (DSM) are obtained. Full details about this dataset can be found at https://doi.org/10.5285/8e483692-3b65-41d2-a7fd-5a3cd589a71c2021-07-28T06:13:41.979983+00:00https://ckan.publishing.service.gov.uk/dataset/ed2ce3fc-9d7d-44c5-8ed8-997e679cc210Scotland's wildness - absence of modern artifacts2023-07-19T02:14:57.318726+00:00One of four component layer of the Scottish map of relative wildness. This layer shows the level of modern artefacts (detractors)that are visible. The dataset is on a scale of 1-256 indicating relative levels of visual influence. Consequently the data is best viewed at a national or regional scale. The methodology is adapted from the 2008 Wildness Study in the Cairngorms National Park. NextMap Digital Surface Model (DSM) gives the height of the surface including the detractors from which a viewshed can be produced. Viewsheds up to 15 km were created for 3 feature layers at 50m resolution, 1) Buildings and other structures, 2) Railway lines, roads and tracks and 3) Pylons and ski lifts. A fourth viewshed up to 30 km was created for wind turbines whose heights were added to a DTM. The resulting calculations were then re-scaled 1-256 to produce the map of lack of built human artefacts.2013-08-26T12:01:20.200743+00:00https://ckan.publishing.service.gov.uk/dataset/835cf20a-8feb-4394-8b30-dcfe840ac13dOS Terrain 50 DTM2023-10-02T18:01:30.115137+00:00Ordnance Survey’s OS Terrain 50 DTM is a dataset representing the physical shape of the real world. The dataset includes 50metre GRID. The DTM data is captured from Ordnance Survey’s large scale aerial imagery. The product is updated and maintained annually.
A free to use topology GIS dataset, to help you visualise simple landscapes in 3D and bring your geographic analysis to life.2019-02-11T15:48:49.101495+00:00https://ckan.publishing.service.gov.uk/dataset/45d864dc-63c4-40d6-8b12-f6450544d6efOS Terrain 5 DTM2023-10-02T18:01:40.866020+00:00Ordnance Survey’s OS Terrain 5 DTM is a dataset representing the physical shape of the real world. The dataset includes 5 metre GRID. The DTM data is captured from Ordnance Survey’s large scale aerial imagery. The product is updated and maintained quarterly.2019-02-11T15:48:34.085825+00:00https://ckan.publishing.service.gov.uk/dataset/ea4611cd-4c92-440a-935a-083c5347c572Area Management - Salmon Fishery Districts2023-11-01T17:07:43.083503+00:00Salmon Fishery District boundaries, used by Scottish Government Marine Scotland for reporting annual salmon catch statistics (which are obtained from salmon catch returns made by the owners/occupiers/agents of salmon fisheries) and for annual salmon stock assessment under the Salmon Conservation (Scotland) Regulations.
District boundaries were interpreted from the Salmon Fisheries (Scotland) Acts 1862 - 1868, and are based on Scottish Environment Protection Agency (SEPA) river catchments and licensed Centre for Ecology and Hydrology (CEH) 1:50,000 data. Boundaries and attributes were updated in 2019 and no further boundary or attribute changes have been required.
Salmon Fishery Districts are available to view as a layer on the Marine Scotland Open Data Network – see Marine Scotland Information pages for Salmon and Sea Trout Fishing at https://marine.gov.scot/themes/salmon-sea-trout-fishing. Boundaries were re-projected from British National Grid (BNG) to WGS84 Web Mercator before upload to Marine Scotland MAPS NMPi.
As the layer was derived by the Scottish Government from a licensed dataset, it is not downloadable or routinely available. It can be shared on request if the user provides evidence that they hold a licence from the Centre for Ecology and Hydrology (CEH) for the 1:50,000 Digital Terrain Model (DTM).2023-11-01T17:07:43.083499+00:00https://ckan.publishing.service.gov.uk/dataset/43696bec-e13b-41fd-b16e-1bf123ee1029Area Management - Salmon Stock Assessment Areas2023-11-01T17:07:43.802864+00:00Salmon Stock Assessment Areas boundaries, used by Scottish Government Marine Scotland to demarcate rivers where salmon stocks are assessed under the Salmon Conservation (Scotland) Regulations 2016. The regulations are amended annually to introduce measures for protecting stocks. Assessment Areas are also used for reporting annual statistics obtained from salmon catch returns made by the owners/occupiers/agents of salmon fisheries.
Assessment Areas boundaries are based on Scottish Environment Protection Agency (SEPA) river catchments and licensed Centre for Ecology and Hydrology (CEH) 1:50,000 data. For 17 salmon Special Areas of Conservation (SAC) the Assessment Areas boundaries include information from Scottish Natural Heritage (SNH) (now NatureScot) and the Joint Nature Conservation Committee (JNCC). Assessment Areas boundaries are a subset of Scottish river catchments, where Marine Scotland has sufficient information on salmon stocks in rivers, or groups of rivers, that their status can be assessed annually and graded for the subsequent fishing season.
Assessment Areas boundaries were updated in 2019 and no further boundary changes have been required. Attributes include annual grade values from 2018 onwards.
Salmon Stock Assessment Areas are available to view as a layer on the Marine Scotland Open Data Network – see Marine Scotland Information pages for Salmon and Sea Trout Fishing at https://marine.gov.scot/themes/salmon-sea-trout-fishing. Boundaries were re-projected from British National Grid (BNG) to WGS84 Web Mercator before upload to Marine Scotland MAPS NMPi.
As the layer was derived by the Scottish Government from a licensed dataset, it is not downloadable or routinely available. It can be shared on request if the user provides evidence that they hold a licence from the Centre for Ecology and Hydrology (CEH) for the 1:50,000 Digital Terrain Model (DTM).
Information on river grades can be found at https://www.gov.scot/publications/salmon-fishing-proposed-river-gradings/pages/overview-and-gradings/2023-11-01T17:07:43.802859+00:00https://ckan.publishing.service.gov.uk/dataset/7f31af0f-bc98-4761-b4b4-147bfb986648LIDAR Composite Digital Terrain Model (DTM) 10m2023-12-18T09:48:05.004745+00:00The LIDAR Composite DTM (Digital Terrain Model) is a raster elevation model covering ~99% of England at 10m spatial resolution. The DTM (Digital Terrain Model) is produced from the last or only laser pulse returned to the sensor. We remove surface objects from the Digital Surface Model (DSM), using bespoke algorithms and manual editing of the data, to produce a terrain model of just the surface.
The digital terrain model has been resampled to 10 metres from the LIDAR Composite DTM 2m dataset using a bilinear interpolation technique.
Produced by the Environment Agency in 2022, the DTM is derived from a combination of our Time Stamped archive and National LIDAR Programme surveys, which have been merged and re-sampled to give the best possible coverage. Where repeat surveys have been undertaken the newest, best resolution data is used. Where data was resampled a bilinear interpolation was used before being merged.
The 2022 LIDAR Composite contains surveys undertaken between 6th June 2000 and 2nd April 2022. Please refer to the metadata index catalgoues which show for any location which survey was used in the production of the LIDAR composite.
The data is available to download as a single GeoTiff raster aligned to the OS National grid. The data is presented in metres, referenced to Ordinance Survey Newlyn and using the OSTN’15 transformation method. All individual LIDAR surveys going into the production of the composite had a vertical accuracy of +/-15cm RMSE. Attribution statement: © Environment Agency copyright and/or database right 2022. All rights reserved.2023-03-24T16:22:37.341233+00:00https://ckan.publishing.service.gov.uk/dataset/8275e71e-1516-42a1-bb0c-4fa73807fe2bLIDAR DTM Time Stamped Tiles2023-12-26T09:08:06.815228+00:00The LIDAR DTM (Digital Terrain Model) Time Stamped Tiles product is an archive of raster elevation data produced by the Environment Agency. Site specific LIDAR surveys have been carried out across England since 1998, with certain areas, such as the coastal zone, being surveyed multiple times. Data is available at varying resolutions of 25cm, 50cm, 1m and 2m, depending on project requirements.
The DTM (Digital Terrain Model) is produced from the last return LIDAR signal. We remove surface objects from the Digital Surface Model (DSM), using bespoke algorithms and manual editing of the data, to produce a terrain model of just the surface.
Available to download as GeoTiff rasters in 5km zipfiles, data is presented in metres, referenced to Ordnance Survey Newlyn and data aligned to the OS Grid. All LIDAR data has a vertical accuracy of +/-15cm RMSE. The transformation used on the data is specific to the time period of survey.
Please refer to the metadata index catalogue which show, for any location, what time stamped data is available, the specific dates of survey, resolution of product and what transformation and geoidal model used. Attribution statement: © Environment Agency copyright and/or database right 2020. All rights reserved.2017-06-22T14:11:55.762317+00:00https://ckan.publishing.service.gov.uk/dataset/977a4ca4-1759-4f26-baa7-b566bd7ca7bfLIDAR Time Stamped Point Cloud2023-12-26T09:13:14.026165+00:00The LIDAR point cloud is an archive of hundreds of millions, or sometimes billions of highly accurate 3-dimensional x,y,z points and component attributes produced by the Environment Agency.
The environment agecy site specific LIDAR DSM and DTM Time Stamped Tiles gridded raster products are derived from the point cloud. The component attributes a point cloud contains can provide valuable additional information to supplement elevation and can enable the user to make bespoke raster products such as canopy height models or intensity rasters.
Site specific LIDAR surveys have been carried out across England since 1998, with certain areas, such as the coastal zone, being surveyed multiple times. The point cloud is available for surveys going back to 2006. Although the DSM and DTM Tile Stamped Tiles products are derived from the point cloud data there may not necessarily be a matching point cloud for each surface model due to historic data archiving processes.
During processing the point cloud classifies the laser returns in the 'ground' and 'surface objects'. Further manual editing undertkaen on the derived digital terrain model (DTM) means the classifed ground points in the point cloud data will not match the final derived DTM.
Data is available in 5km download zip files for each year of survey. Within each downloaded zip file are LAZ files aligned to the Ordinance Survey grid. The size of each tile is dependent upon the spatial resolution of the data.
Please refere to the coverage metadata files for the start and end date flown of a survey as well as additional component information the point cloud contains such as the average point density. Attribution statement: © Environment Agency copyright and/or database right 2019. All rights reserved.2017-06-22T14:02:35.377436+00:00https://ckan.publishing.service.gov.uk/dataset/b2a13ea4-ff37-4da9-be2e-a1bc5e5c55b31m LIDAR Composite DSM & DTM for Scotland2024-01-05T11:42:03.439262+00:00This metadata record is for Approval for Access product AfA458. Light Detection and Ranging (LIDAR) is an airborne mapping technique, which uses a laser to measure the distance between the aircraft and the ground. Up to 300,000 measurements per second are made of the ground, allowing highly detailed terrain models to be generated at spatial resolutions of between 25cm and 2 metres.
The Environment Agency’s LIDAR data archive contains digital elevation data derived from surveys carried out by the Environment Agency's specialist remote sensing team.
This dataset is derived from a combination of our full dataset which has been merged and re-sampled to give the best possible coverage. Data is available at 2m, 1m, 50cm, and 25cm resolution. The dataset can be supplied as a Digital Surface Model produced from the signal returned to the LIDAR (which includes heights of objects, such as vehicles, buildings and vegetation, as well as the terrain surface) or as a Digital Terrain Model produced by removing objects from the Digital Surface Model.
The dataset can be presented as an ESRI Binary Grid which contains height values, or as a georeferenced JPEG which is an image showing what LIDAR looks like when loaded into specialist software. Attribution statement: © Environment Agency copyright and/or database right 2016. All rights reserved.2016-07-14T10:38:26.277263+00:00https://ckan.publishing.service.gov.uk/dataset/5b943c08-288f-4d47-a924-a51adda6d288Seagrass Potential2024-01-05T11:42:05.285176+00:00Seagrass Potential Summary:
Seagrass potential areas derived from wave and current energy, elevation and salinity criteria.
Guidance and Limitations:
The Seagrass Potential Area layer provides a national ‘high level’ indication of where intertidal and subtidal seagrass could potentially be restored based on some key physical attributes. It should be considered as an initial aid to identifying sites. The areas identified are based on outputs from large scale models and should not always be assumed to precise at the local level.
The location of significant activities (such as dredging) and marine assets (such as submarine cables), which could restrain a location’s potential, have not been factored in in the creation of this layer. The presence of such activities and structures should of course be considered at an early stage before making any local selection of suitable sites.
It should not be assumed that all the areas identified meet all environmental conditions required to re-establish seagrass habitat or that seagrass beds currently only exist within these areas. Instead it aims to provide an initial attempt to identify potential areas at a national level. Furthermore, it is probable that there are some areas outside the areas identified that could be suitable for restoration. The data is not directly derived from any specific historic records of seagrass, and does not represent the historic extent of seagrass.
Seagrass Potential Description:
Seagrass potential areas were primarily derived from the EMODnet 2016 wave and current energy models. This data was combined with seabed digital elevation models (DEMs sourced from Defra Marine DEM and EMODnet Composite 2018 DTM) and Environment Agency turbidity data to determine potential seagrass habitat areas. Areas of low salinity were also screened out based on Environment Agency salinity monitoring and modelling data.
Selection Criteria used habitat preferences for Zostera marina and Z. noltei identified by the Marine Life Information Network (MarLIN) as follows:
Wave = Low Energy, <11.41 Nm-2 (mean of annual 90th percentile values over six years)
Current = Low Energy, <130 Nm-2, (mean of annual 90th percentile values over six years)
Elevation (waterbodies with low turbidity <10mg/l) = Between -10m and +5m above sea level.
Elevation (waterbodies with medium and high turbidity >10mg/l) = Between -5m and +5m above sea level.
Salinity = >10 (mesohaline, polyhaline)
Further areas were removed, including existing saltmarsh (sourced from EA saltmarsh extent inventory) and small discrete areas <400m2. Small areas were also removed based on expert judgement and their close proximity to major ports.
Finally, each polygon was assigned a water body and river basin district based on the WFD cycle2 Transitional and Coastal Water Body layer. Attribution statement: © Environment Agency copyright and/or database right 2015. All rights reserved.2020-05-07T14:46:33.268151+00:00https://ckan.publishing.service.gov.uk/dataset/56c928df-2513-42a8-89c6-14d739247e1150cm LIDAR Composite DSM & DTM for Scotland2024-01-05T11:42:12.619984+00:00This metadata record is for Approval for Access product AfA458. Light Detection and Ranging (LIDAR) is an airborne mapping technique, which uses a laser to measure the distance between the aircraft and the ground. Up to 300,000 measurements per second are made of the ground, allowing highly detailed terrain models to be generated at spatial resolutions of between 25cm and 2 metres.
The Environment Agency’s LIDAR data archive contains digital elevation data derived from surveys carried out by the Environment Agency's specialist remote sensing team.
This dataset is derived from a combination of our full dataset which has been merged and re-sampled to give the best possible coverage. Data is available at 2m, 1m, 50cm, and 25cm resolution. The dataset can be supplied as a Digital Surface Model produced from the signal returned to the LIDAR (which includes heights of objects, such as vehicles, buildings and vegetation, as well as the terrain surface) or as a Digital Terrain Model produced by removing objects from the Digital Surface Model.
The dataset can be presented as an ESRI Binary Grid which contains height values, or as a georeferenced JPEG which is an image showing what LIDAR looks like when loaded into specialist software. Attribution statement: © Environment Agency copyright and/or database right 2016. All rights reserved.2016-07-14T10:39:44.156432+00:00https://ckan.publishing.service.gov.uk/dataset/95df1b2b-dc6a-479c-9685-40291a46ec2c2m LIDAR Composite DSM & DTM for Scotland2024-01-05T11:45:52.408333+00:00This metadata record is for Approval for Access product AfA458. Light Detection and Ranging (LIDAR) is an airborne mapping technique, which uses a laser to measure the distance between the aircraft and the ground. Up to 100,000 measurements per second are made of the ground, allowing highly detailed terrain models to be generated at spatial resolutions of between 25cm and 2 metres.
The Environment Agency’s LIDAR data archive contains digital elevation data derived from surveys carried out by the Environment Agency's specialist remote sensing team.
This dataset is derived from a combination of our full dataset which has been merged and re-sampled to give the best possible coverage. Data is available at 2m, 1m, 50cm, and 25cm resolution. The dataset can be supplied as a Digital Surface Model produced from the signal returned to the LIDAR (which includes heights of objects, such as vehicles, buildings and vegetation, as well as the terrain surface) or as a Digital Terrain Model produced by removing objects from the Digital Surface Model.
The dataset can be presented as an ESRI Binary Grid which contains height values, or as a georeferenced JPEG which is an image showing what LIDAR looks like when loaded into specialist software. Attribution statement: © Environment Agency copyright and/or database right 2016. All rights reserved.2016-07-14T10:39:27.522554+00:00https://ckan.publishing.service.gov.uk/dataset/abe9bb9d-b99e-4d43-bed2-06e7b4d5701dLIDAR Composite - Coverage and Extents for Scotland2024-01-05T11:47:19.753818+00:00This dataset shows each tile available and the extent of data in each individual tile that went into the merging process to create the LIDAR Composite DSM & DTM. The data is supplied as a shapefile.
This metadata record is for Approval for Access product AfA458. Light Detection and Ranging (LIDAR) is an airborne mapping technique, which uses a laser to measure the distance between the aircraft and the ground. Up to 300,000 measurements per second are made of the ground, allowing highly detailed terrain models to be generated at spatial resolutions of between 25cm and 2 metres.
The Environment Agency’s LIDAR data archive contains digital elevation data derived from surveys carried out by the Environment Agency's specialist remote sensing team.
This dataset is derived from a combination of our full dataset which has been merged and re-sampled to give the best possible coverage. Data is available at 2m, 1m, 50cm, and 25cm resolution. The dataset can be supplied as a Digital Surface Model produced from the signal returned to the LIDAR (which includes heights of objects, such as vehicles, buildings and vegetation, as well as the terrain surface) or as a Digital Terrain Model produced by removing objects from the Digital Surface Model.
The dataset can be presented as an ESRI ASCII Raster which contains height values, or as a georeferenced JPEG which is an image showing what LIDAR looks like when loaded into specialist software. Attribution statement: © Environment Agency copyright and/or database right 2016. All rights reserved.2016-07-14T10:39:58.770467+00:00https://ckan.publishing.service.gov.uk/dataset/e529ca2f-b4ce-403e-8cef-ab821061c4f3LIDAR Composite Digital Terrain Model (DTM) 2m2024-03-08T17:07:47.502149+00:00The LIDAR Composite DTM (Digital Terrain Model) is a raster elevation model covering ~99% of England at 2m spatial resolution. The DTM (Digital Terrain Model) is produced from the last or only laser pulse returned to the sensor. We remove surface objects from the Digital Surface Model (DSM), using bespoke algorithms and manual editing of the data, to produce a terrain model of just the surface.
Produced by the Environment Agency in 2022, the DTM is derived from a combination of our Time Stamped archive and National LIDAR Programme surveys, which have been merged and re-sampled to give the best possible coverage. Where repeat surveys have been undertaken the newest, best resolution data is used. Where data was resampled a bilinear interpolation was used before being merged.
The 2022 LIDAR Composite contains surveys undertaken between 6th June 2000 and 2nd April 2022. Please refer to the metadata index catalgoues which show for any location which survey was used in the production of the LIDAR composite.
The data is available to download as GeoTiff rasters in 5km tiles aligned to the OS National grid. The data is presented in metres, referenced to Ordinance Survey Newlyn and using the OSTN’15 transformation method. All individual LIDAR surveys going into the production of the composite had a vertical accuracy of +/-15cm RMSE. Attribution statement: © Environment Agency copyright and/or database right 2022. All rights reserved.2023-03-09T16:02:47.326963+00:00https://ckan.publishing.service.gov.uk/dataset/01b3ee39-da3f-47b6-83da-dc98e73a461fLIDAR Composite Digital Terrain Model (DTM) - 1m2024-03-08T17:11:04.528242+00:00The LIDAR Composite DTM (Digital Terrain Model) is a raster elevation model covering ~99% of England at 1m spatial resolution. The DTM (Digital Terrain Model) is produced from the last or only laser pulse returned to the sensor. We remove surface objects from the Digital Surface Model (DSM), using bespoke algorithms and manual editing of the data, to produce a terrain model of just the surface.
Produced by the Environment Agency in 2022, the DTM is derived from a combination of our Time Stamped archive and National LIDAR Programme surveys, which have been merged and re-sampled to give the best possible coverage. Where repeat surveys have been undertaken the newest, best resolution data is used. Where data was resampled a bilinear interpolation was used before being merged.
The 2022 LIDAR Composite contains surveys undertaken between 6th June 2000 and 2nd April 2022. Please refer to the metadata index catalgoues which show for any location which survey was used in the production of the LIDAR composite.
The data is available to download as GeoTiff rasters in 5km tiles aligned to the OS National grid. The data is presented in metres, referenced to Ordinance Survey Newlyn and using the OSTN’15 transformation method. All individual LIDAR surveys going into the production of the composite had a vertical accuracy of +/-15cm RMSE. Attribution statement: © Environment Agency copyright and/or database right 2022. All rights reserved.2023-03-09T16:02:58.125467+00:00https://ckan.publishing.service.gov.uk/dataset/c9dd994d-9649-4041-96d4-cdc0f1a53152Overland Flow Pathways2024-03-15T15:05:03.578687+00:00The Most Probable Overland Flow Pathway dataset is a polyline GIS vector dataset that describes the likely flow routes of water along with potential accumulations of diffuse pollution and soil erosion features over the land.
It is a complete network for the entire country (England) produced from a hydro-enforced LIDAR 1-metre resolution digital terrain model (bare earth DTM) produced from the 2022 LIDAR Composite 1m Digital Terrain Model. Extensive processing on the data using auxiliary datasets (Selected OS Water Network, OS MasterMap features as well as some manual intervention) has resulted in a hydro-enforced DTM that significantly reduces the amount of non-real-world obstructions in the DTM. Although it does not consider infiltration potential of different land surfaces and soil types, it is instructive in broadly identifying potential problem areas in the landscape.
The flow network is based upon theoretical one-hectare flow accumulations, meaning that any point along a network feature is likely to have a minimum of one-hectare of land potentially contributing to it.
Each segment is attributed with an estimate of the mean slope along it.
The product is comprised of 3 vector datasets; Probable Overland Flow Pathways, Detailed Watershed and Ponding and Errors. Where Flow Direction Grids have been derived, the D8 option was applied. All processing was carried out using ARCGIS Pro’s Spatial Analyst Hydrology tools. Outlined below is a description of each of the feature class.
Probable Overland Flow Pathways
The Probable Overland Flow Pathways layer is a polyline vector dataset that describes the probable locations accumulation of water over the Earth’s surface where it is assumed that there is no absorption of water through the soil. Every point along each of the features predicts an uphill contribution of a minimum of 1 hectare of land. The hydro-enforced LIDAR Digital Terrain Model 1-Metre Composite (2022) has been used to derive this data layer. Every effort has been used to digitally unblock real-world drainage features; however, some blockages remain (e.g. culverts and bridges. In these places the flow pathways should be disregarded. The Ponding field can be used to identify these erroneous pathways. They are flagged in the Ponding field with a “1”. Flow pathways are also attributed with a mean slope value which is calculated from the Length and the difference of the start and end point elevations. The maximum uphill flow accumulation area is also indicated for each flow pathway feature.
Detailed Watersheds
The Detailed Watersheds layer is a polygon vector dataset that describes theoretical catchment boundaries that have been derived from pour points extracted from every junction or node of a 1km2 Flow Accumulation dataset. The hydro-enforced LIDAR Digital Terrain Model 1-Metre Composite (2022) has been used to derive this data layer.
Ponding Errors
The Ponding and Errors layer is a polygon vector dataset that describes the presence of depressions in the landscape after the hydro-enforcing routine has been applied to the Digital Terrain Model. The Type field indicates whether the feature is Off-Line or On-Line. Off-Line is indicative of a feature that intersects with a watercourse and is likely to be an error in the Overland Flow pathways. On-line features do not intersect with watercourses and are more likely to be depressions in the landscape where standing water may accumulate. Only features of greater than 100m2 with a depth of greater than 20cm have been included. The layer was derived by filling the hydro-enforced DTM then subtracting the hydro-enforced DTM from the filled hydro-enforced DTM.
Please use with caution in very flat areas and areas with highly modified drainage systems (e.g. fenlands of East Anglia and Somerset Levels). There will occasionally be errors associated with bridges, viaducts and culverts that were unable to be resolved with the hydro-enforcement process.
Attribution statement: © Environment Agency copyright and/or database right 2023. All rights reserved. 2024-03-15T15:05:03.578683+00:00https://ckan.publishing.service.gov.uk/dataset/cdca725a-ff58-4025-8af5-498c93df2901G-BASE (Geochemical Baseline Survey of the Environment) for south west England - stream sediments and shallow (5-20cm) soils2024-03-22T15:09:26.384540+00:00The G-BASE programme involves systematic sampling and the determination of chemical elements in samples of stream sediment, stream water and soil, to build up a picture of the surface chemistry of the UK. G-BASE for SW England is the most recent area of the UK sampled by this on-going project The average sample density for stream sediments is approximately one site per 2km square. Density for soils in SW England is variable across the area, ranging from 1 per 2km square to one per 5km square, depending on underlying parent material. Analytical precision is high with strict quality control to ensure countrywide consistency. Results have been standardised to ensure continuity with existing G-BASE geochemical data. The data provide baseline information on the natural abundances of elements, against which anomalous values due to such factors as mineralisation and industrial contamination may be compared. Analytical data for the sub150 microns fraction of stream sediment and the sub 2mm fraction of soil samples are available for some or all of: Ag, Al, As, Ba, Bi, Br, Ca, Cd, Ce, Cl, Co, Cr, Cs, Cu, Fe, Ga, Ge, Hf, I, In, K, La, Mg, Mn, Mo, Na, Nb, Nd, Ni, P, Pb, Rb, S, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Te, Th, Ti, Tl, U, V, W, Y, Yb, Zn, and Zr.2015-03-02T11:33:22.330797+00:00https://ckan.publishing.service.gov.uk/dataset/77a78bed-4fba-4344-964c-eb670dcec229Department for Environment, Food and Rural Affairs (DEFRA) MCZ: North Celtic Deep: Multibeam Survey NCLD_3_2012: Western Channel & Celtic Sea (01/03/2012 to 01/04/2012)2024-03-22T15:13:57.764258+00:00MBES (MultiBeamEchoSounder) bathymetry and backscatter data obtained using a Simrad EM710. Processed using Caris HIPS and SIPS 7.1 to produce a digital terrain model (dtm) of the bathymetric surface. These data are archived with the Marine Environmental Data and Information Network (MEDIN) Data Archive Centres (DACs) including the British Geological Survey (BGS) DAC for geology and geophysics, The Archive for Marine Species and Habitats Data (DASSH) and the United Kingdom Hydrographic Office (UKHO) bathymetry DAC. The full site data package including raw is also available on request from BGS.2023-02-23T02:11:20.755227+00:00https://ckan.publishing.service.gov.uk/dataset/f0db0249-f17b-4036-9e65-309148c97ce4National LIDAR Programme2024-03-26T17:57:13.314790+00:00The Environment Agency National LIDAR Programme provides accurate elevation data at 1m spatial resolution for all of England.
In 2017 we divided the country into 302 survey blocks covering all of England which were subsequently captured during the winter months (approximately November to April each year) between January 2017 and February 2023. These are known as our 'Phase 1' national lidar programme surveys.
Subsequently we have undertaken repeat surveys of specific blocks based on the on-going requirements for upto date elevation data. Each repeat survey block is given a new incrementing phase number, for example the second time we capture a block this is that blocks 'phase 2' whilst the 3rd time will be 'phase 3'. There is not curretly a plan to capture all the origianl phase 1 survey blocks over a rolling programme with repeat surveys be based on the requirements for upto date elevation data for an area.
All data is published through the DEFRA Data Services survey portal on a quartely on-going bases and a number of different products area available for each survey block. All products are available in 5km tiles aligned to the ordnance survey grid. The tiles are named by the unique survey id, OS grid reference and the first and last survey date of the survey id (P_XXXXX_OSOSOS_SDFLOWN_EDFLOWN.*). The surface models are available in GeoTiff raster format whilst the point cloud is available in *.laz. An index catalogue is also available with provides survey specific information about each tile.
Outlined below is a description of each product that is available for each survey block:
LIDAR Point Cloud: is the discrete LIDAR returns that are used in the creation of the surface models. Supplied in *.laz format they the discrete LIDAR returns have been classified into ground, low, medium and high vegetation classes using an automated classification process.
Digital Surface Model(s) (DSM) are created from the last or only LIDAR pulse returned to the sensor and contains all ground and surface objects.
Digital Terrain Model(s) (DTM) is created from the last return LIDAR pulse classified as ground, filtering out surface objects. Manual filtering is undertaken on the DTM to improve the automated classification routines to produce a most likely ground surface model. Areas of no data, such as water bodies, are also filled to ensure there are no gaps in the model.
First Return Digital Surface Model(s) (FZ DSM) is created from the either the first or only LIDAR pulse returned to the sensor and contains all ground and surface objects. It is more likely to return elevations from the top or near top of trees and the edges of buildings. It can often be used in canopy height modelling and production of building outlines.
Intensity Surface Model(s) (Int DSM) is a measure of the amount of laser light from each laser pulse reflecting from an object. This reflectivity is a function of the near infrared wavelength used and varies with the composition of the surface object reflecting the return and angle of incidence.The intensity surface model produces a grayscale image where darker surfaces such as roads reflect less light than other surfaces such as vegetation. Attribution statement: © Environment Agency copyright and/or database right 2022. All rights reserved.2019-05-02T08:38:18.666308+00:00