Groundwater flow dynamics of weathered hard-rock aquifers under climate-change conditions: an illustrative example of numerical modeling through the equivalent porous media approach in the north-western Pyrenees (France)

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Hydrogeological Characteristics of Shallow Hard Rock Aquifers in Yaounde (Cameroon, Central Africa)

“…In addition, depth investigation data (beyond 8 m), based on pumping tests or slug tests, indicating the level/horizon actually investigated, were also taken into account in the hydraulic description of this aquifer. Hydraulic conductivity values from infiltration tests range from 10 −7 to 10 −3 m/s [12,36]. The normal distribution (Figure 4) of the hydraulic conductivity values is unimodal and varies over four orders of magnitude, attesting the variability of this propriety of the loose materials.…”

“…Various techniques, as reported in the literature, are used to determine the hydrodynamic properties of aquifers in basement areas in general and its superficial part in particular. They include but are not limited to field methods (pumping test, slug test and tracer test, Porchet test) [12,22,34]; laboratory and mathematical methods [35], empirical formulas [36], and regional methods [37,38]. Even though accurate estimation of hydrodynamic proprieties (effective porosity, permeability, and transmissivity) may be conducted in the field environment, poor knowledge of aquifer geometry sometimes limits their potential application [39].…”

“…At the scale of the soil profile (Figure 3), the hydraulic conductivity varies between 10 −6 and 10 −4 m/s in the loose superficial level, 10 −5 and 10 −4 m/s in the glebular set, 10 −7 and 10 −6 m/s in alloterite, and 10 −6 and 10 −5 m/s in isalterite horizon [11,17]. At the well scale (slug test), these values vary from 5.13 × 10 −6 m/s Hydrogeological Characteristics of Shallow Hard Rock Aquifers in Yaounde (Cameroon, Central… DOI: http://dx.doi.org /10.5772/intechopen.84631 in the glebular set [36] to 5.8 × 10 −5 m/s in saprolite [17] for a transmissivity of 2.3 ± 1.5.10 −4 m 2 /s [8]. The effective porosity determined at the sample scale is 7.4% [47].…”

Economic analysis of heating for an enhanced geothermal system based on a simplified model in Yitong Basin, China

“…The analytical solutions are difficult to accurately describe complex coupling processes, while the numerical simulation method can solve these problems better. The numerical methods mainly include four different approaches, namely discrete fracture network (DFN), equivalent porous media (EPM), fractured continuum (FC), and equivalent pipe network (EPN) . Cao developed a transient 3D numerical model to describe THM coupling considering the thermal‐pore‐elastic model.…”

Groundwater in fractured bedrock environments: managing catchment and subsurface resources – an introduction

“…Various conceptual approaches have been developed in the past decades to describe and model the groundwater flow through fractured rock masses (NRC 1996), ranging from equivalent continuum models (Carrera et al 1990;Bear 1993;Hadgu et al 2017) to discrete fracture network simulation models (Dverstorp & Andersson 1989;Cacas et al 1990a, b, c;Davy et al 2006;Makedonska et al 2015). Numerical simulations have been employed to investigate flow and transport processes from the local to the field and catchment scale (MacQuarrie & Mayer 2005;Jaunat et al 2016;Janos et al 2018), reconciling scale-specific monitoring data or aiming to integrate multiscale surveying data. Numerous case studies have been performed in fractured crystalline rock in the framework of the safety assessments for nuclear waste repositories (Herbert et al 1991;Neretnieks 1993;Joyce et al 2014), investigating flow and transport phenomena on the small scale and on a regional scale (Voborny et al 1991(Voborny et al , 1994.…”