@article{fdi:010096045,
  title = {{A}re there biases in borehole databases of weathered basement aquifers affecting their reliability to estimate aquifer productivity ?},
  author = {{K}inglo, {A}. {A}. and {H}ector, {B}asile and {G}aliez, {C}. and {K}o{\¨ie}ta, {M}. and {L}achassagne, {P}atrick and {L}awson, {F}. and {V}ouillamoz, {J}ean-{M}ichel},
  editor = {},
  language = {{ENG}},
  abstract = {{G}roundwater from weathered basement aquifers ({WBA}s) is a strategic water resource, but its potential for resource development remains poorly characterized. {M}eanwhile, groundwater abstraction from {WBA}s is growing to meet water and food security needs in most sub-{S}aharan {A}frican countries. {I}n this study, the impact of the instructions given to water borehole drillers on the characterization of {WBA} properties was assessed by modelling {WBA} short-term productivity using a novel numerically based, stochastic modeling approach. {T}he numerical modeling of 10,000 synthetic {WBA}s reveals systematic biases in borehole databases due to instructions given to water borehole drillers, such as the discharge target ({Q}(target)) together with the maximum allowed borehole depth ({Z}(max)) and the minimum allowed borehole depth ({Z}(min)). {I}nsufficient drilling depth below the base of the saprolite ({Z} <= 35 m) leads to undersampling of deeper water-bearing fracture, causing an underestimation of aquifer productivity and fractured-layer thickness (> 10%). {T}hese biases persist across discharge targets (0.5-10 m(3)/h) and are exacerbated by shallow drilling. {M}oreover, traditional borehole-database-processing methodologies, fail to account for instructions given to water borehole drillers, misrepresenting useful aquifer thickness ({L}u) by up to 100%. {T}o enhance accurate use of drilling databases, several approaches could be considered: (1) classify boreholes by exploration depth and instantaneous discharge, excluding shallow borehole data (<= 35 m below the base of saprolite); (2) archive drilling instructions ({Q}(target), {Z}(max) and {Z}(min)) to contextualize data limitations; and (3) adopt robust indicators like specific capacity and depth-dependent yield instead of instantaneous discharge.},
  keywords = {{W}eathered basement aquifer ; {N}umerical modeling ; {S}aprolite ; {F}ractured layer ; {B}orehole database},
  booktitle = {},
  journal = {{H}ydrogeology {J}ournal},
  volume = {[{E}arly access]},
  numero = {},
  pages = {[23 p.]},
  ISSN = {1431-2174},
  year = {2026},
  DOI = {10.1007/s10040-025-02991-3},
  URL = {https://www.documentation.ird.fr/hor/fdi:010096045},
}