Improving hydrogeological understanding through well-test interpretation by diagnostic plot and modelling: a case study in an alluvial aquifer in France ; Mejora en el conocimiento hidrogeológico a través de la interpretación de ensayos de pozos mediante parcelas de diagnóstico y modelización: un estudio de caso en un acuífero aluvial en Francia ; Amélioration de la compréhension hydrogéologique grâce à l’interprétation des essais de puits par diagnostic et modélisation: une étude de cas dans un aquifère alluvial en France ; Melhorando o conhecimento hidrogeológico por meio da interpretação de testes de poço por gráficos de diagnóstico e modelagem: um estudo de caso em um aquífero aluvial na França ; 通过诊断图和模拟的试井解释提高水文地质的认识:以法国冲积含水层为例

As part of the Springer Nature Content Sharing Initiative, you can publicly share full-text access to a view-only version of your paper by using thefollowing SharedIt link: https://rdcu.be/cCd8u ; International audience ; The study of groundwater resources using pumping test data is usually carried out with the Theis solution, which enables the hydraulic parameters of porous aquifers such as the transmissivity and storage coefficient, to be estimated from the water-level drawdown. However, the data fitting can fail and provide only an indication that the pumped aquifer has a complex structure. Here, a diagnostic plot on log-derivative drawdown is used to identify flow regimes and thus aquifer heterogeneities, leading to plausible conceptual models. Nevertheless, the diagnostic plot is insufficient and must be accompanied by further modelling because of the nonuniqueness of the drawdown log-derivative signal. The proposed approach is applied to an alluvial plain in France, known to be complex because the deposition processes change over time, resulting in channel belts limited by low-permeability deposits in the floodplain or three-dimensional (3D) interconnected structures. Six analytical models were used to simulate drawdown and its derivatives during a three-day transient pumping test. The diagnostic performed on the pumping well showed that four conceptual models, with highly contrasted hydrodynamic behaviours, may correspond to the diagnostic. The joint use of pumping-well and observation-well data allowed the only appropriate model to be identified—a dual-permeability model characterizing a multilayer aquifer. The conceptual model matched the geological observations in boreholes and corroborates the fluvial sequence stratigraphy of the alluvial plain. The pumping test used here is a tool to explore the 3D architecture of the fluvial reservoir at the scale of the depositional sequence in the floodplain. ; El estudio de los recursos hídricos subterráneos a partir de los datos de los ensayos de bombeo suele ...