Detection of water leak from a mortar wall buried in sand by geophysical survey methods

Abstract

Small-loop EM and GPR surveys were carried out for imaging the ground water to detect water leak from a mortar wall buried in an artificial sandy test field. Both methods are suitable for surveys of small-scale water leaks. Apparent resistivity distribution obtained by small-loop EM surveys outlined water leaks. (1) When test field was unsaturated, whole of the test field was imaged with high apparent resistivity. (2) Relatively low resistivity zone was appeared when water contents were increased. GPR surveys obtained smaller scale of subsurface information. (1) When the depth of water table measured in the vicinity of the mortar war, it clearly imaged at the depth of about 1.4m below the ground surface. (2) Water leak from the mortar wall was delineated as 10 cm rise of water.