GSI Landslides Susceptibility Mapping Project

GSI Landslides Susceptibility Mapping Project

The Geological Survey of Ireland (GSI) has awarded a contract to consultants Mouchel Ireland Ltd. to undertake landslides susceptibility mapping in two designated areas within Ireland. The contract began on 23 June 2008 and will last for several years. The two areas are

(1) East Leinster from Clogher Head in Co. Louth down to Arklow in South Wicklow and west as far as Trim and Newbridge

East Leinster

(2) the Greater Cork City Area from the hills north of Cork city to the sea and from Bandon eastwards to Killeagh near Youghal.

Greater Cork City

The study in both areas will include the coastal zone. These two areas include the major development zones in the country, and both in terms of infrastructure and housing and commercial development, the vulnerability of the landscape to slope instability by way of landslides needs to be assessed to minimise risk to development and to human life, so as to plan for sustainable development in the future. The project is important in the context of climate change where more intense rainfall is predicted for Ireland as well as higher sea levels affecting the coastal zone.

The study consists of doing an in depth analysis of the landscape to identify areas which are more vulnerable to landsliding. Such a land zonation would be an important guide for planning authorities in terms of development control. A wide variety of earth science datasets will be used to do this work. The areas are divided into segments or cells of land each of which are uniquely characterised by the combination of ground conditions which occur in each of them. The datasets to be used will include bedrock geology, Quaternary (unconsolidated deposits) geology, soils, vegetation and land use, slope gradient and aspect, rainfall and other weather data. Such landslide vulnerability studies have been done in many parts of the world and a specific methodology to suit Irish conditions will be developed at the outset of the project. As well as the thematic datasets listed above, remote sensing methods such as satellite imagery, black and white and colour photography, will used. A geotechnical assessment of the properties of rock and soil will also be undertaken in specific areas.

Dr. Ronnie Creighton

Landslides Project Manager

Geological Survey of Ireland