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The geophysical investigation of lake water seepage in the regulated environment of the Bosherston Lily Ponds, South Wales, UK. Part 1: natural, fracture‐related pathways
Author(s) -
Husband Claire R.,
Cassidy Nigel J.,
Stimpson Ian G.
Publication year - 2009
Publication title -
near surface geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.639
H-Index - 39
eISSN - 1873-0604
pISSN - 1569-4445
DOI - 10.3997/1873-0604.2009042
Subject(s) - geology , hydrogeology , bedrock , electrical resistivity tomography , ground penetrating radar , natural (archaeology) , environmental geology , regional geology , hydrology (agriculture) , engineering geology , karst , geophysics , geomorphology , mining engineering , tectonics , volcanism , geotechnical engineering , paleontology , radar , telmatology , telecommunications , engineering , computer science , electrical engineering , electrical resistivity and conductivity
The detection and characterization of hydrological pathways is applicable to many branches of geosciences including contaminant hydrogeology, mining, civil engineering and petroleum geology. Geological features play a critical role in fluid transportation through the presence of enhanced hydraulic conductivity pathways, although determining their exact contribution is difficult. This paper reports the results of geophysical investigations at the Bosheston Lily Ponds in Pembroke, South Wales, UK where the lake system has experienced unexplained water loss for over thirty years. The area is classified a Special Area of Conservation (SAC) and is managed under tight regulatory regime that limits the scope and extent of any site investigations. Geophysical surveys focused on identifying any natural hydraulic conduits/pathways in the underlying carboniferous limestone where the main objectives were to determine whether bedrock fracturing is promoting natural water loss. Ground‐penetrating radar (GPR), electrical resistance tomography (ERT) and self‐potential (SP) surveys were collected at targeted site locations and the information gained used to ascertain the nature of the observed/predicted lake water loss. The results show that localized zones of high‐density, small‐scale fracturing in the limestone bedrock are likely to be the predominant cause of lake water loss with little evidence of larger scaled, open karstic features.