groundwater-resources-sand-and-gravel-aquifers-140000-ireland-roi-itm
Data Resources (4)
WMS
WMS
SHP
ESRI Shapefile
ESRI REST
ESRI REST
DATA VIEWER
Data Viewer
Data Resource Preview - WMS
Téama | Eolaíocht |
---|---|
Dáta eisithe | 2013-01-15 |
Dáta nuashonraithe | 2021-10-22 |
Cloíonn an tacar sonraí leis na caighdeáin seo | The INSPIRE Directive or INSPIRE lays down a general framework for a Spatial Data Infrastructure (SDI) for the purposes of European Community environmental policies and policies or activities which may have an impact on the environment. |
Nótaí Cearta | ['Creative Commons Attribution 4.0 International (CC BY 4.0)', 'Data that is produced directly by the Geological Survey Ireland (GSI) is free for use under the conditions of Creative Commons Attribution 4.0 International license.\n\nhttps://creativecommons.org/licenses/by/4.0/\n\nhttps://creativecommons.org/licenses/by/4.0/legalcode\n\nUnder the CC-BY Licence, users must acknowledge the source of the Information in their product or application.\n\nPlease use this specific attribution statement: "Contains Irish Public Sector Data (Geological Survey Ireland) licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence".\n\nIn cases where it is not practical to use the statement users may include a URI or hyperlink to a resource that contains the required attribution statement.', 'license'] |
Minicíocht Nuashonraithe | Eile |
Teanga | English |
Lamairne | https://gsi.geodata.gov.ie/portal/apps/webappviewer/index.html?id=d333a8a9b6ab44378411fc0d973db4ef |
Clúdach Geografach i bhformáid GeoJSON | {"type":"Polygon","coordinates":[[[-10.47472, 51.44555],[-10.47472, 55.37999], [-6.01306, 55.37999], [-6.01306, 51.44555], [-10.47472, 51.44555]]]} |
SRS | Irish Transverse Mercator (ITM, EPSG:2157) |
Méid Ingearach | {"verticalDomainName": "sea level", "minVerticalExtent": "0", "maxVerticalExtent": "0"} |
Eolas Dualfhoinse | Sand and Gravel Aquifers Geologists map and record information on the composition and structure of sand and gravel subsoil types and the composition of these, and information from boreholes (a deep narrow round hole drilled in the ground). Areas are drawn on a map to show the distribution of the sand and gravel subsoil types. The map was created using the following datasets: Teagasc subsoils 1:40,000 (Teagasc/EPA), Quaternary 1:40,000 (GSI), wells and springs database (GSI), exposures database (GSI), Sand and Gravels Aquifer map (GSI). There are two sand and gravel aquifer categories: • Rg - A sand/gravel aquifer is classed as regionally important if it can supply regionally important abstractions (e.g. large public water supplies with ‘excellent’ yields >400 m3/d). It is highly permeable, more than 10 m thick or has a saturated thickness of at least 5 m, and should extend over at least 5 km2, and usually over 10 km2. • Lg - Locally Important Sand/Gravel Aquifer: Similar to a Regionally Important Sand/Gravel Aquifer (Rg), but with a smaller continuous area (c.1-10 km2) and/or less consistent permeability. Although the aquifer may supply ‘excellent’ yields, the smaller size limits the amount of recharge available to meet abstractions. The sand and gravel aquifer data are shown as polygons. Each polygon holds information on: • ‘Gravel body’ – the name of the aquifer • ‘Aquifer Category’ – aquifer category code • ‘Aquifer Description’ – description of the aquifer category • ‘Comments’ – notes regarding the area • ‘Confidence’ – a confidence level associated with the delineation of the area as an aquifer To create the map, initially, the Quaternary Sediments 1:50,000 Ireland (ROI) ITM dataset was used for the extraction of all sand and gravel bodies across Ireland. These were then screened in ArcGIS (ArcMap v. 9.3), and small areas that did not have the required area for a Locally Important Sand and Gravel Aquifer were excluded. Where it was known that the surface expression of sands and gravels was only a small portion of the subsurface body, and where most of the sands and gravels were thus buried by other sediments, such areas were retained. This process left several hundred sand and gravel bodies remaining as a starting point for field work. Field work included a visit to each of the areas which had the potential to be (at least) a Locally Important Sand and Gravel Aquifer owing to its area. In such areas, gravel pits and sand pits were visited and depth and type of sediment recorded, other exposures into the subsurface were visited and logged, wells (whether Public Supply, Group Scheme or private farm or domestic) were dipped and any information on depths recorded, and data was collected where geological and hydrogeological data existed for the area. Back in the office, data were then entered and where a sand and gravel body had qualifying aquifer properties (either 10m depth sand and gravel, or 5m depth saturated sediments), these areas were digitised in ITM on ArcMap v. 9.3. Zones which would then become drawn down if pumping from this area of qualifying aquifer properties, but themselves had not sufficient depth to qualify as an aquifer, were also outlined. The area which actually formed the aquifer body was then ascertained and drawn up. Such areas formed the basic building blocks for the sand and gravel aquifer shapefile, which included details on the aquifer name, area, type of aquifer (Rg or Lg), confidence level, county, and any important aspects to note for each body. A legend was generated for this shapefile, and a style file produced. Work was carried out by GSI staff in close collaboration with Quaternary geologists and hydrogeologists, and the final product was quality checked. Data topology was also checked. Errors noted and recorded were corrected. Data topology was checked. In some counties, sand and gravel aquifer maps from GWPSs prior to 2000 were available. These counties included Clare, Donegal, Laois, Limerick, Louth, Meath, Roscommon, Offaly, Tipperary North Riding and Wicklow. Teagasc mapped the distribution of sand and gravel subsoils in the late 1990s and early 2000s, as part of the EPA /Teagasc Soil and Subsoil Mapping Project. This led to the production of a map in 2006 showing where sands and gravels lay under the ground surface across the entirety of the Republic of Ireland. Data were digitized using ATLAS photogrammetric software and converted to ArcGIS 8.x shapefiles. The Sand and Gravel aquifer map that included the GWPS county aquifers was updated using the new Teagasc subsoils map in the period January to December 2008, to create the first National Sand and Gravel aquifer map. Small updates to this map were made at different localities in 2010, 2011, 2013 and 2014 on the basis of new information received. GSI further refined the Quaternary map in 2014, when the All Ireland Quaternary Map coverage was produced. This coverage was a GIS shapefile in ITM projection, and coding was used to attach attribute information to the data layers from the table of sands and gravels. A legend was generated. Geologists then examined, between 2015 and 2018, all areas of significant sand and gravel deposits across Ireland (over two hundred and fifty separate areas). Data were collected from sand and gravel pits, trenches, and other exposures, and three dimensional cross sectional models of the sand and gravel bodies were produced. The amount of annual throughput (which is the amount of groundwater available in the sand and gravel body, arising from the infiltration of rainwater into them) was then calculated, for each of the areas. Those bodies that had significant amounts of throughput available were classed as aquifer, and ranked in terms of their importance. Naming conventions were standardized. Data topology checked. In 2021, the data structure was reviewed and a new database was created in ArcGIS Enterprise. Using ArcGIS Pro 2.6.3, the dataset was renamed as part of a GSI data standardisation process. Sand_and_Gravel_Aquifer_40K_IE26_ITM A standardised dataset alias was added. A unique id field was added. A new unique identifier was added for each record using an attribute rule. Most fields were renamed and an alias added. Domains were created for relevant fields to ensure attribute integrity for those fields. The attribute values can only be added from pre-defined GSI tables in the form of drop-down values. Attribute rules were set up to automatically insert certain values eg unique identifier. The data was cleaned using a GSI notebook. This checked the attribute values contained valid domain values and a spell check was carried out. Some manual cleaning of obvious errors was also carried out. Metadata was updated to new GSI standard. |
Tréimhse ama clúdaithe (tús) | 2005-04-15 |
Tréimhse ama clúdaithe (deireadh) | 2019-09-11 |