Rainfall threshold assessment
Gavin and Doherty Geosolutions was commissioned by GSI to conduct research on behalf of the Geological Survey of Ireland.
The aim of the project was to provide an analysis of landslide occurrences throughout Ireland. The analysis is based on a large volume of landslide inventory data collated through recent projects and research, which involves a statistical interrogation of existing landslide database records and analysis of failure mechanisms.
The project also includes inspection of meteorological data in order to define the weather warning level for landslides in the form of rainfall thresholds. An overview of the testing and monitoring techniques suitable for typical landslides in Ireland was provided and a pilot project monitoring strategy based on this was defined and presented.
Scope of Work:
GDG analysed the available data to identify and describe the most common landslide types/mechanisms in Ireland. The analysis provided insights on landslide causes, behaviour and impacts.
The soil properties analysis focused on the permeability and shear strength of the two most common soil types associated with Irish landslides (Peat and Glacial Till).
We proposed a monitoring methodology suitable for Irish conditions based on our detailed analyses and understanding of the landslides mechanisms, triggering conditions and the various types of soil and stratigraphy.
In addition, GDG presented an example of an Early Warning System which could be implemented by local Authorities to advise on likely landslide events.