Geoelectrical and hydro-chemical monitoring of karst formation at the laboratory scale

Abstract

Abstract. Ensuring sustainable strategies to manage water resources in karst reservoirs requires a better understanding of the mechanisms responsible for conduits formation in the rock mass and the development of detection methods for these hydrological and geochemical processes. In this study, we monitored the electrical conductivity of two limestone core samples during controlled dissolution experiments. We interpret the results with a physics-based model describing the porous medium as effective structural parameters that are tortuosity and constrictivity. We obtain that constrictivity is more affected by calcite dissolution compared to tortuosity. Based on our experimental results and data sets from the literature, we show that the characteristic Johnson length is a valuable structural witness of calcite dissolution impact linking electrical and hydrological properties.

A microfluidic chip for geoelectrical monitoring of critical zone processes

“…Calcite dissolution is expected to increase the in-phase conductivity 4 as observed between t 0 and t 2 in Fig. 5.…”

“…Compared with the image series, the trend of the quadrature conductivity at low frequencies appears linked to the decrease of the available reactive surface of the calcite crystal. 3.5 Impact of the bubbles on the SIP acquisition Calcite dissolution is expected to increase the in-phase conductivity 4 as observed between t 0 and t 2 in Fig. 5.…”

“…1 Detailed understanding of the water-rock interactions in the CZ is of great importance in many areas of applied science and engineering, 2 including contaminant transfers and mineral reactivity. 3,4 Calcite is one major mineral of the CZ whose reactive transport study is significant for applications ranging from risk management with the survey of dissolution-driven karstification, 5,6 to subsurface bioremediation by precipitation. 7 Furthermore, the characterization of calcite reactivity is relevant across scales, from understanding the underlying microscopic mechanisms to predicting its impact on catchment behavior.…”