100K Seamless Bedrock GIS Project
This project has been undertaken by a cross functional team of GSI staff from the Bedrock, Groundwater, Cartography and Information Management Programmes. The aim was to take the individual 1:100K scale Bedrock Geology Series maps and produce from them a Seamless National Bedrock Geology covergage in GIS (Geographic Information System) format. The project was facilitated by the fact that the Bedrock maps are produced in digital format, being digitised in AutoCad© and theafter imported into ArcInfo© for attribution and map production. A principal driver for the production of the new map was the requirement of a seamless National Groundwater Bedrock Aquifer Map for the Groundwater Programme work on the EU Water Framework Directive project. The steps involved in the 100K Seamless Bedrock Geology project were as follows:
The seamless map is now available on GSI's webmapping site, under the Bedrock dataset.
- Bedrock Geologist, Markus Pracht, re-codes the Geological units and structures to give unique national coding (and colours).
- Recoded units from individual sheets were combined in a single GIS database and maps were digitally edgematched and joined, and checked for internal errors by Eddie MacMonagle (Cartography) and Grainne O'Shea (GIS-Groundwater).
- Map joins and mis-matches were then re-checked with Markus for geological veracity.
- Finally the seamless map layers (Bedrock Unit polygons, narrow bedrock lines and structurtal lines) were combined for sale and distribution on a CD, including explanatory documents and images of the original sheets including their explanatory legends.
As a result of this project GIS use across the organisation has been hugely facilitated and customers can now acquire seamless Bedrock Geological data at 1:100K scale for any area of interest in the country. In particular the map provides the basis for the new project to produce Bedrock Geology Ground Truth maps at 1:50,000 scale. The project was featured in the GSI 2002 annual Report as "Maps without Edges" and in recognition of their work the project team were recipients of a GSI staff prize.