ERT survey for characterising the subsurface of a golf course build over the edge of a volcanic caldera (Canary Islands)

Abstract

Knowledge of geometry and hydraulic properties of the unsaturated zone is essential to assess the dynamics of the subsurface drainage of water that seeps from the ground surface, whether it is rain water as excess of irrigation. This interest increases when irrigation is conducted with reclaimed water, as it happens on the golf course of Bandama which since 1976 is being watered with reclaimed water from the wastewater treatment plant (WWTP) of the city of Las Palmas de Gran Canaria. The golf course of Bandama is located on the edge of the volcanic caldera of the same name and occupies an area approximately 30 hectares of which some 14.5 ha are irrigated by sprinkling. This work arises to determine the characteristics of the subsoil under golf course by electrical resistivity tomography method, with particular interest in trying to delimit the areas of preferential drainage affecting vulnerability to contamination of the underlying aquifers.