Landslides in Ireland

Landslides in Ireland

​​​​​​​​The term "landslide" describes a wide variety of processes that result in the downward and outward movement of materials under the force of gravity; this includes materials like rock, debris, earth, mud and peat, or a combination of these.  Ireland's location, terrain and climate result in landslides occurring mainly in areas with steep slopes where rock meets the surface and peat covers the terrain.

Landslides have the potential to cause great havoc, and have done so all around the world. They have resulted in massive loss of life and damage to infrastructure. Landslides can damage roads, railways, canal embankments, and cause dams to fail. They can destroy or severely damage buildings of all types – housing, commercial or industrial property. Rivers can become blocked or diverted by sediment or rock displaced by landslides.

The consequences of this can include flooding, pollution of watercourses and the killing of fish stocks. Agricultural land can be sterilised in the short to medium term. It does not require spectacularly huge landslide events to cause serious disruption or loss of life. Relatively small landslides in terms of the volume of material displaced can damage bridges and roads, and also cause injury and death. These potential impacts of landslides, irrespective of their size, mean that the scale of the problem for Ireland in the past and into the future needs serious attention so that the susceptibility of the Irish landscape to slope instability can be properly assessed. Ireland is fortunate not to be in an extreme high risk to major geohazards. Indeed, in comparison to many other countries, Ireland may be regarded as a benign environment in terms of landslide hazard.


 

What can increase the chances of a landslide?

Underlying ​​​RockRock type, grain size, what the rock is made of, degree of weathering
Physical featuresslope elevation, slope incline, direction the slope is facing
Drainageslope drainage direction, how fast the ground drains
Land Covervegetation type, land use
Rainfalltotal amount, intensity, time interval
Natural erosionslope surface, base of slope
Man-madeundercutting of slopes, removal of retaining walls, land drainage
Volcanoes and EarthquakesNot a major factor in Ireland


 

Landslides in Ireland Publication

​Following two major landslide incidences in Ireland in 2003 in Galway and Mayo the Geological Survey of Ireland (GSI) established the Irish Landslides Working Group (ILWG) in 2004. In 2006 the report 'Landslides in Ireland' was published by the group which outlined a number of topics related to landslides and their context in Ireland including the geotechnics of landslides, landslide mapping, landslides and planning, research and recommendations for future work. In the last 15 years the GSI has carried out extensive work in relation to building a national landslides database and also carrying out national landslide susceptibility mapping.

National Landslides Database

​As part of the initial work of the Irish Landslides Working Group a comprehensive database of landslide events in Ireland was compiled. Landslide events, the earliest of which dates back to 1488, were added from a variety of sources. This dataset was fundamental to future work carried out on landslide mapping in particular to Landslide Susceptibility Mapping and for the study of landslide hazard in Ireland. The National Landslides Database has been restructured and incorporated into a Geodatabase as part of the development of the GSI's dedicated Landslide Viewer and as part of a recommendation from the Irish Landslide susceptibility Mapping Project. The database now holds more 2,500 events.