There are two fundamental approaches to the mathematical modelling of karst systems; distributive models and global models. Distributive models use theoretical concepts such as simplified aquifer geometry and hydrodynamic flow equations to simulate the hydraulic behaviour of karst aquifers. Global models concentrate on mathematically deriving a relationship between input and output, where the input is usually a precipitation event and output the spring discharge time series. Both approaches were considered when modelling groundwater floods in Ireland.

The modelling work was broadly divided into two categories:

Global modelling

A generic global modelling approach was developed that could be applied to individual flood sites based on limited site-specific data such as water level, rainfall, and topography. This approach considered each site independently and did not incorporate information on the wider groundwater system. The primary objective of the global modelling approach was to develop predictive relationships between antecedent rainfall and flooding within individual turlough basins. These models supported the reconstruction of hydrological time series for flood frequency analysis and provided key data to estimate predictive flood levels. The predictive groundwater flood maps were predominantly derived using this approach.

Distributive modelling

The GWFlood project provided 30 months funding for a postdoctoral researcher in Trinity College Dublin to refine and enhance a pre-existing distributed groundwater model of the Gort Lowlands catchment, Co. Galway. The objective of this research project was to enhance a pre-existing hydrological model of the catchment and work with Galway County Council to research the effects of various engineered flood mitigation measures on local and catchment hydrology. For more information on this project, see here and here.