Dept. of Civil, Structural & Environmental Engineering
Characterisation of diffuse recharge into karst aquifers using chemical and numerical modelling techniques
Keywords: Ireland; karst; groundwater; hydrograph separation; environmental tracer; numerical modelling; climate change.
Approximately 50% of Ireland is underlain by Carboniferous limestone, of which 90% can be considered as lowland (<150 masl). Groundwater flow in limestones follows heterogeneous flow paths caused by the nature of different porosities, i.e. a primary (intergranular/diffuse), a secondary (fractured due to tectonic stress) and tertiary porosity (conduit due to dissolution).
The aim of the research is to investigate three separate karst aquifers in Ireland with particular emphasis on the characterisation of the diffuse recharge aspect in order to develop more realistic numerical models of the systems. These models can then be used to make predictions as to the aquifer response due to climate change, develop engineering solutions to potential flooding predictions and to evaluate contaminant transport and land-use options.
The investigative techniques will involve both chemical (isotopic and trace element water quality) and spring hydrograph source separation techniques. Water quality sampling will be required in order to analyse for a suite of rare earth and trace elements as well as isotopic fractionation techniques particularly targeting lithium isotopes.
The research is conducted within the framework of the Irish Centre for Research in Applied Geosciences (ICRAG). iCRAG is funded under the SFI Research Centres Programme and is co-funded under the European Regional Development Fund.
Project Supervisor: Prof. Laurence Gill