Featured case study
Mapping Ardmore in the 1926 Census
April 22, 2026How I built a local-history GIS site for Ardmore using the newly released 1926 Census records, static data exports, townland mapping, and careful data cleaning.
GIS, Public Data, and
Place-based Research
I'm Dónal O'Tiarnaigh. I build spatial analysis projects, local-history tools, and public-data experiments that turn scattered records into clearer, more useful stories.
Flagship Work
Two projects that best show the direction of the portfolio
These are the clearest examples of how I approach GIS, public records, and purpose-built tools: start with a place, clean the data, and make the result easier to explore.
Practice Areas
What the work on this site tends to focus on
Local History and Place-based Research
Rebuilding historical records around one town, parish, or landscape so they can be searched, mapped, and understood in context.
Public Data and Monitoring Tools
Turning fragmented feeds, thresholds, and agency datasets into practical interfaces that help people see what is happening right now.
Spatial Analysis and Mapping Methods
Using GIS, remote sensing, and statistical mapping techniques to explain patterns in health, environment, population, and place.
Recent Writing
Project archive and supporting write-ups
The rest of the site mixes recent builds with earlier GIS coursework adapted for the web. Together they show both current direction and the methods underneath it.
Using Sentiment Analysis to Surface Spatial Signals in Social Media Data
April 22, 2025A sentiment-analysis workflow in R comparing Bing, NRC, and AFINN lexicons on a large tweet dataset as groundwork for future geospatial text analysis.
Mapping Dublin's Air Quality
March 10, 2025A GIS analysis of street-level air pollution in Dublin using mobile monitoring data, Empirical Bayesian Kriging, and WHO threshold mapping.
Mapping Dublin's Population Change with R
February 15, 2025A comparative choropleth mapping project using R to show how Dublin's electoral-district population changed between 2006 and 2016.
Mapping Healthcare Access and Vulnerability in Ireland
January 29, 2025A national GIS analysis combining electoral-district vulnerability indicators with hospital proximity to highlight underserved areas across Ireland.
Hello World
January 25, 2025Welcome to the show: A quick intro to the blog and my hopes for it going forward
Background
GIS work shaped by software, analysis, and communication
I'm based in the south of Ireland and work across GIS, data tooling, and technical problem-solving. If you want more context on how I work, the About page fills in the longer version.