Study region: Bell Harbour. A sub-catchment of karst landscape, the Burren, in Western
Study focus: Bell Harbour is difficult to investigate using traditional hydrogeological techniques
due to its complex mixture of upland, lowland and coastal karst, with ephemeral
lakes and submarine/intertidal discharges. This study uses electrical resistivity tomography
and discrete conduit network modelling to characterise the hydrogeology of the catchment
by determining flow pathways and their likely hydraulic mechanisms.
New hydrological insights for the region: Results suggest two primary pathways of northwards
groundwater flow in the catchment, a fault which discharges offshore, and a ∼2 m
diameter karst conduit running underneath the catchment lowlands against the prevailing
geological dip. This conduit, whose existence was suspected but never confirmed, links
a large ephemeral lake to the coast where it discharges intertidally. Hydraulic modelling
indicates that the conduit network is a complex mixture of constrictions with multiple
inlets and outlets. Two ephemeral lakes are shown to be hydraulically discontinuous, either
drained separately or linked by a low pressure channel.