A cost-effective device and methodology to compute aquifer transmissivity and piezometry from free-flowing artesian wells

Abstract

Artesian aquifers offer interesting opportunities for water supply by providing a low-vulnerability groundwater resource that is easily abstracted without any installation of pumps or power supply costs. However, hydraulic tests are challenging to perform, notably where the piezometric head is above ground level with free-flowing wells not equipped with valves and open for years. This paper describes a low-cost, easy to reproduce and adaptable device, the free-flowing artesian well device (FFAWD), which is mainly designed with a set of PVC tubes equipped with a pressure probe and a valve. This device is used to perform hydraulic tests on free-flowing artesian wells, to measure the piezometric head of the aquifer and to compute its transmissivity. The practical use of the FFAWD is described and a method is proposed to compute the piezometric head and the transmissivity of the aquifer from this data set (free-flowing well discharge and pressure increase measurements) with any adapted analytical solution, using the Houpeurt-Pouchan method. Artefacts such as post-production effects, surge effects, and the impact of a leaky well are identified to avoid any misinterpretation. The FFAWD was applied to the volcano-sedimentary artesian plain of Pasuruan (Indonesia). The advantages and limitations of using the device, along with the interpretation methodology, are also discussed.

Water cycle modelling strengthened by probabilistic integration of field data for groundwater management of a quite unknown tropical volcanic hydrosystem

“…At the foot of these steep slopes, lava flows transition to alternations of detrital and distal ash fallout layers that form peripheral detrital aprons. Lower down, the aprons become alluvial floodplains, with alternating laharic formations and fine-grained soils, which can prevent the upwelling of underlying groundwater, creating artesian aquifers [Toulier et al, 2022]. This layering of geological formations related to the distribution of volcanic formations spatially disconnects the surface watersheds from underground ones [Charlier et al, 2011, Dumont et al, 2021, Vittecoq et al, 2014.…”

Characterization of the productivity of basement aquifers at Bagoué region (North of Côte d’Ivoire)

“…4,7 Otherwise, some hydro geophysical studies in Ghana and Nigeria highlighted a joint inversion method to estimate aquifer hydrodynamic parameters like transmissivity or hydraulic conductivity by using theoretical relationship named Dar Zarrouk parameters derived from Ohm's law of current flow and Darcy's law for fluid flow in a medium 8,9 At volcano-sedimentary artesian plain of Pasuruan (Indonesia) the transmissivity value of artesian aquifer was computed from a free-flowing well artesian discharge data by following the transient state Houpeurt-Pouchan method when the recovery curve is interpreted as a drawdown curve with the help of either Jacob's or Theis's solution or any adapted analytical solution such as the Cooper-Jacob. 10 Nowadays, many researchers use model for estimating aquifer productivity parameters like hydraulic head and transmissivity. That option of research is fast and can be robust but, it is more critical due uncertainties around modelling results.…”