The ‘Pathways Project’ was carried out by a consortium of Trinity College Dublin, University College Dublin and Queen’s University Belfast, funded by the EPA under the STRIVE initiative. The project developed a CMT that may be employed by RBD management to ensure that appropriate measures may be taken to achieve and/or retain good WFD status. The project objectives were as follows:
- Identification of significant hydrological pathways within RBDs
- Quantification of flows along the identified hydrological pathways
- Identification of significant pathways for diffuse pollutant transport and attenuation, with particular emphasis on the attenuation of nutrients (nitrogen and phosphorus species), and particulate matter (pathogenic micro-organisms and sediments)
- Identification of critical source areas (CSAs) for diffuse pollutants reaching groundwater, surface water and relevant ecological receptors
- Development of a CMT suited to Irish conditions and in line with the requirements of the end-user.
Determination of hydrological pathways contributing to streamflow in Irish catchments
A detailed understanding of flow and contaminant transfer along each of the key hydrological pathways within a catchment is critical for designing and implementing cost effective Programmes of Measures under the Water Framework Directive. The key pathways of interest in Ireland are overland flow, interflow, shallow groundwater flow and deep groundwater flow. Little is known about the interflow pathway and its relative importance in delivery of flow and contaminants to the streams.
The aim of this research is to develop a refined conceptual model of overland flow and interflow as flow pathways within each study catchment, together with an improved understanding of the transport and attenuation of pollutants along these pathways, and an estimate of pollutant loads.
This research will provide the framework for temporal proportioning of streamflow into its constituent pathways. Analysis of physical data, collected in the field and obtained from EPA, GSI, OPW and Met Eireann datasets, is used to inform and calibrate lumped, semi-lumped and distributed numerical hydrological models.