A landslide is the movement of material down a slope. This includes rock, earth, mud and peat. Landslides in Ireland mainly occur on steep mountain slopes.
A landslide susceptibility map shows areas where a landslide could occur, how likely it will occur and what causes them. The likelihood is measured from low to high. The map is created using a method called the Unique Condition Unit (UCU). A unique condition unit is an area with a set of ground types. It tells us what the soil type is, what the slope is (angle of the ground) and where water flows. When many landslides occur in a unit, the map will show high landslide susceptibility.
The landslide susceptibility classification map is to the scale 1:50,000 (1 cm on the map relates to a distance of 500m) It is a vector dataset. Vector data portray the world using points, lines, and polygons. A polygon represents an area. The landslide susceptibility data is shown as polygons. Each polygon gives information on the unit, its soil type, the slope of the ground, its description and the description of landslide susceptibility (High or low).