Flow heterogeneity in the fractured Chalk aquifer of southern England

The aim of the current work is to investigate the heterogeneity of flow in the Chalk aquifer of southern England. The rock mass properties and hydraulic characteristics of the aquifer have been characterised using a suite of geological and geophysical surveys and hydraulic tests. Fracture logs have been produced based on core logging and using optical images of boreholes. Flow has been characterised using borehole flow logs and dilution tests and hydraulic conductivity measured using packer tests. Fractures have been recorded with apertures in the range <1mm to about 30cm (sub-karstic enlargement) in diameter, however, hydrogeologically significant flow is not restricted to the enlarged fractures and is affected by the local groundwater head distribution. The work is being undertaken as part of the LOCAR Programme. LOCAR is a multi-project programme with the aim of measuring and modelling processes controlling water and material fluxes within lowland permeable catchments in the UK.