Development of a conceptual groundwater flow model using a combined hydrogeological, hydrochemical and isotopic approach: A case study from southern Benin

Hydrogeological Modeling in Tropical Regions via FeFlow

“…An unwanted effect in this situation can be the appearance of unrealistic parameter distributions, or the calibration falling into a local minimum without exploring other declines (Hu & Jiao, 2015;Klaas et al, 2017). Bearing in mind that the calibration process does not guarantee the total model reliability and that the results obtained are as real as the veracity in the assumptions used in the conceptual model (Betancur, Mejia, & Palacio, 2009;Kpegli, Alassane, van der Zee, Boukari, & Mama, 2018;Linde, Renard, Mukerji, & Caers, 2015), it is appropriate to analyze the sensitivity and uncertainty associated with the parameters. The uncertainty in the hydrogeological models is related to: i.)…”

Flow characterization and modelling of a South Benin artesian aquifer system : Effects of hydraulic and storage properties and recharge on simulated heads across the artesian zone

“…Two main piezometric surveys were conducted, the first in November 2015 (rainy season) and the second in February 2017 (dry season). The first piezometric survey included 560 wells (see the Electronic Supplementary Material by Kpegli et al, 2018a) and the second included 513 wells. Each of the piezometric surveys was undertaken over the period of a week to ensure groundwater levels were comparable.…”

“…The altitudes (land surface elevation) of the measurement points were extracted from a Digital Elevation Model (DEM, Figure 1 of the Electronic Sepplementary Material by Kpegli et al, 2018a) using ArcGis software. Groundwater heads were determined by subtracting the Static Water Levels from the land surface elevation (i.e., ℎ 𝑖𝑖𝑖𝑖 = 𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 𝐸𝐸𝐸𝐸 − 𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆 (Castany, 1998), see Figure 2.4).…”

“…Groundwater heads were determined by subtracting the Static Water Levels from the land surface elevation (i.e., ℎ 𝑖𝑖𝑖𝑖 = 𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 𝐸𝐸𝐸𝐸 − 𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆 (Castany, 1998), see Figure 2.4). Applying the equation ℎ 𝑖𝑖𝑖𝑖 = 𝑧𝑧𝑧𝑧 𝑖𝑖𝑖𝑖 + ℎ 𝑝𝑝𝑝𝑝, 𝑖𝑖𝑖𝑖 (see Castany, 1998;Post and Asmuth, 2013) to determine the groundwater heads is also feasible (see the Electronic Supplementary Material by Kpegli et al, 2018a). However, in that case, the mean depths of the wells screens have to be considered as illustrated on Figure 2.4.…”

“…The results from the piezometric survey (November 2015) are reported in Table 1 of the Electronic Supplementary Material (ESM, by Kpegli et al, 2018a) and were used to draw the piezometric map of the Turonian-Coniacian aquifer (Figure 2.5). The flow directions for the February 2017 piezometric survey is similar to the one of November 2015, and therefore not shown in this paper.…”