Environmental Geophysical Study of the Groundwater Mineralization in a Plot of the Cotonou Littoral Zone (South Benin)

Abstract

Geophysical investigations comprising electrical resistivity and electromagnetic conductivities methods were deployed in a 350 m2sector, strewn with 11 wells. Within the framework of an environmental study on a small scale in the south of Benin, the water conductivity of these wells was measured to determine in a direct way mineralization of the coastal water table in the littoral zone. This environmental study aimed to prospect by the geophysical methods the space extension of the water table mineralization obtained by direct measurements of water conductivity in the well and the depth of the fresh water/salted water interface in the coastal aquifer. Electromagnetic measurements of conductivities made it possible to chart a gradient of mineralization in the northwest direction. The logs of vertical electric soundings showed a deepening of the fresh water/salted water interface in the southern part and its rupture in the northern part. The electrical resistivities of the interface are sensitive to the degree of its mineralization. It has been observed that the geophysical methods in electrical and electromagnetic prospection are a great contribution to the environmental study of the water table mineralization in the littoral zone for a sustainable management of the water resource.

Groundwater Potential Assessment Using 2-D Resistivity Method In Kluang, Johor (Malaysia)

“…From the overall results, confined aquifer can be seen at 2 different zones which flows through lines R1 to R3. Gunung Lambak hills that is located 6 km from the study area in the southwest Table 1: Resistivity values of common rocks and materials (Nicaise et al, 2012).…”

An unconventional method for calculating porosity of marine clay deposits using the 2D resistivity method

“…The lowest ρ value from the trimmed data is denoted as the X-limit, while the highest one as the Y-limit. Based on Nicaise et al (2012) and Ravindran, Ramanujam and Sudarsan (2013), SPyCRID considers saturated soil with X-limit less than 1 m as brackish pore-fluid condition. SPyCRID utilizes the trimmed ρ values by assigning the lower ρ values as to be representing ρ w , under the assumption that these values are unaffected by the soil particles while the higher ρ values signify the added influence of soil grains on the ρ values; hence, these values are taken as ρ o (e.g.…”

“…8) has a small rootmean-square error of 3.2% (Batayneh 2006;Abdul-Nafiu et al 2013). Based on reported resistivity values for clayey soils and the general pattern of the resistivity profile, the saturated soil was distinguished as having ρ values of 0.6 to 3.2 m (Braga, Malagutti Filho and Dourado 2006;Nicaise et al 2012). Although the measured ρ values of the soil from the 2-DRI can be regarded to be presenting the bulk resistivity, SPyCRID segregates them into two Archie's variables, ρ w and ρ o .…”

Effectiveness of geophysical surveys for water wells relocation in overexploited aquifers (the example of Maggiore and Traversola Valleys, Northwestern Italy)

“…Soupios et al 2010;Batte et al 2008;Cimino et al 2007;Kafri and Goldman 2005;Young et al 2004) and different recent literature works are available to document the effectiveness of these methods with this aim (e.g. Parsekian et al, 2017;Nicaise et al, 2012;Sirhan et al 2012;Ezersky et al, 2011). Particularly many regional case histories are available to demonstrate the utility of Time Domain Electromagnetic Methods (TDEM) for groundwater exploration.…”