New map gives insight into Ireland’s land cover types

Data from a new map has provided up-to-date insights on the types of land in Ireland, and how much of the country is covered by each of them.

Ordinance Survey Ireland (OSI) and the Environmental Protection Agency (EPA) started a new national land cover mapping programme in 2018.

The work was completed in September 2022, while the map and associated data was published last month.

To date, the only source of national-scale land cover data in Ireland has been the European Environment Agency’s Co-ordinated Information on the Environment (CORINE) land cover data series.

The final report of the new National Land Cover (NLC) Map of Ireland said that the CORINE map is not suitable for use in detailed land assessments, due to spatial resolution of only 25ha, and its classification system, which is based on typical European land cover that is not reflective of land types in Ireland.

To date, there has not been a recognised national land cover classification system for Ireland. The new map aims to rectify that by outlining a system of categorising Irish land types.

The new classification system is divided into two levels. The ‘Level 1’ classifications are as follows:

• Artificial surfaces;
• Exposed surfaces;
• Cultivated land;
• Forest, woodland and scrub;
• Grassland, saltmarsh and swamp;
• Peatland;
• Heath and bracken;
• Waterbodies.

Each of these (with the exception of cultivated land) is further subdivided into ‘Level 2’ classifications.

For example, the grassland, saltmarsh and swamp Level 1 class is made up of Level 2 classes including improved grassland, amenity grassland, dry grassland, and wet grassland; and the peatland Level 1 class is made up of Level 2 classes including raised bog, blanket bog, and cutover bog.

Using these classes, the land types and the extent of their cover in Ireland can be understood.

The data for the Level 1 classes is outlined in the table below:

The figures for each of these classes are different than the figures reported for Ireland in the corresponding classes for the European CORINE map.

These variances between the two maps ranged from less than 1% to almost 10%, depending on the class.

At Level 2 land type classification, the top 10 classes according to land cover were as follows (cultivated land is both a Level 1 and Level 2 class):

• Improved grassland (41.53% or 2,933,299ha);
• Wet grassland (9.47% or 668,548ha);
• Cultivated land (6.05% or 427,033ha);
• Transitional forest (5.46% or 385,672ha);
• Coniferous forest (3.63% or 256,443ha);
• Blanket bog (3.54% or 249,738ha);
• Wet heath (3.25% or 229,526ha);
• Hedgerows (3.18% or 224,787ha);
• Dry heath (2.82% or 199,256ha);
• Broadleaf forest and woodland (2.42% or 170,859ha).

The NLC Map of Ireland report also outlines a county-by-county breakdown of these land types (at the Level 1 class).

Counties in the east and south have a much higher percentage cover of cultivated land than other regions. Counties Louth, Wexford and Carlow have the highest percentage of cultivated land cover (27.91%, 27.09%, and 25.04% respectively).

Counties Wicklow, Leitrim, and Clare have the highest percentage of forest at 27.09%, 25.71%, and 24.64% respectively.

Counties Monaghan and Limerick have the highest proportion of grassland, at 74.95% and 71.87% respectively.

The new map is available from Tailte Éireann, a recently-established state body which OSI has been amalgamated into.