Groundwater Prospection in Grande Comore Island—Joint Contribution of Geophysical Methods, Hydrogeological Time-Series Analysis and Groundwater Modelling

  • Anli Bourhane
  • Jean-Christophe Comte
  • Jean-Lambert Join
  • Kassim Ibrahim
Part of the Active Volcanoes of the World book series (AVOLCAN)


In Grande Comore island, groundwater is the only safe water resource for drinking but only one third of the population have access to this resource. All existing wells are drilled in the volcanic aquifers of the coastal zone. Among them, about one third provide groundwater of acceptable salinity (less than 1 g/L), one third provide water of salinity comprised between 1 and 3 g/L, and the remaining third is generally disused due to salinities higher than 3 g/L. To date, inland groundwater resources have been largely overlooked. The development of groundwater in Grande Comore requires an improved understanding of the complex young volcanic aquifers, quantitatively and qualitatively. This work applies an integrated hydrogeological methodology aiming at improving the conceptual understanding of Grande Comore volcanic aquifers in both coastal and inland areas, and proposing a robust approach for prospecting and managing the groundwater resources. This methodology comprised (1) a review of the current hydrogeological knowledge regarding the structure, properties and conceptualisation of the volcanic aquifers, (2) the spatial characterisation of both aquifer structures and seawater intrusion in coastal areas, through the implementation of geophysical surveys comprising electrical resistivity tomography (ERT) and time-domain electromagnetic soundings (TDEM), (3) the characterisation of coastal groundwater dynamics through the acquisition of high temporal resolution heads and salinity measurements in three wells from contrasted hydrogeological settings, (4) the quantification of the impact of volcanic heterogeneity on coastal groundwater salinity through numerical groundwater modelling and (5) the exploration of the poorly known inland aquifers through the interpretation of ERT and TDEM investigations together with a discussion of the hydrogeological analogy with the better known volcanic island of La Réunion. Results reveal a strong potential for both further developing coastal aquifers and initiating the prospection of inland aquifers, and provide methods for improving the management of existing groundwater infrastructures.


Lava Flow Electrical ResistivityResistivity TomographyTomography Seawater Intrusion United Nation Development Program Vertical Electrical Sounding 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The ground geophysical investigation programme was funded by the French Development Agency (AFD) through the Grande Comore Groundwater Development Programme. We acknowledge the Comoros Department of Energy, Mining and Water (DGEME) for technical assistance on fieldwork through the involvement of 10 temporary workers; Hamid Soule, manager of the Karthala Volcano Observatory and PhD student in the Réunion Laboratory of Geosciences for great logistic support; Mahabadi Boinali and Said Ahmed Othman, hydrogeologists at DGEME for helpful and constructive discussions; the NERC-UPGro programme for financial contribution to the instrumentation of TP5 well; and finally the Air Austral Company for offering a weight excess for freight of geophysical equipment. Finally, we acknowledge the review of H. Celle-Jeanton which contributed in improving the final manuscript.


  1. Albouy Y, Andrieux P, Rakotondrasoa G et al (2001) Mapping coastal aquifers by joint inversion of DC and TEM soundings-three case histories. Ground Water 39:87–97CrossRefGoogle Scholar
  2. Bachelery P, Coudray J (1993) Carte géologique de la Grande Comore au 1/50 000 ème, avec notice explicative, 39 pGoogle Scholar
  3. Bates B, Kundzewicz ZW, Wu S, Palutikof J (2008) Climate change and water. IPCC Tech Pap VI x + 200 ppGoogle Scholar
  4. Boinali M (1982) Géologie et esquisse hydrogéologique de l’archipel volcanique des Comores. 45pGoogle Scholar
  5. Bret L, Join J-L, Legal X et al (2003) Argiles et zéolites dans l’altération d’un volcan bouclier en milieu tropical (Le Piton des Neiges, La Réunion). C R Geosci 335:1031–1038CrossRefGoogle Scholar
  6. Coudray J, Mairine P, Nicolini E, Clerc JM (1990) Approche hydrogéologique. Volcanisme Lî La Réun. Cent. Rech. Volcanol, Clermont-FerrandGoogle Scholar
  7. Custodio E, Cabrera MC (2012) The Canary Islands. Water Agric. Environ. Spain Can We Sq. Circ. Chapter 22 p 281Google Scholar
  8. Comte JC (2008) Apport de la tomographie électrique à la modélisation des écoulements densitaires dans les aquifères côtiers - Application à trois contextes climatiques contrastés (Canada, Nouvelle-Calédonie, Sénégal). Université d’AvignonGoogle Scholar
  9. Comte JC, Banton O, Join JL, Cabioch G (2010) Evaluation of effective groundwater recharge of freshwater lens in small islands by the combined modeling of geoelectrical data and water heads. Water Resour Res 46 doi: 10.1029/2009WR008058
  10. Ecker A (1976) Groundwater behaviour in Tenerife, volcanic Island (Canary Islands, Spain). J Hydrol 28:73–86. doi: 10.1016/0022-1694(76)90053-6 CrossRefGoogle Scholar
  11. Dahlin T (1993) On the automation of 2D resistivity surveying for engineering and environmental applications, Ph.D. thesis, Dept. Eng. Geol., Lund Univ., Lund, Sweden. Ph.D Thesis, Lund UniversityGoogle Scholar
  12. Dahlin T, Zhou B (2004) A numerical comparison of 2D resistivity imaging with 10 electrode arrays. Geophys Prospect 52:379–398. doi:  10.1111/j.1365-2478.2004.00423.x
  13. Danielsen JE, Auken E, Jørgensen F (2003) The application of the transient electromagnetic method in hydrogeophysical surveys. J Appl Geophys 53:181–198Google Scholar
  14. Folio JL (2001) Distribution de la perméabilité dans le massif du Piton de la Fournaise : apport à la connaissance du fonctionnement hydrogéologique d’un volcan-bouclier. La RéunionGoogle Scholar
  15. Griffiths DH, Turnbull J, Olayinka A. (1990) Two-dimensional resistivity mapping with a computer-controlled array. First Break. doi:  10.3997/1365-2397.1990008
  16. Ghyben WB (1888) Nota in verband metde voorgenomen putboring nabij Amsterdam-Tijdsch. Van Kouinglijk Inst Van Ing 8–22Google Scholar
  17. Guo W, Langevin CD (2002) A computer program for simulation of three-dimensional variable-density ground-water flow. Tech. Water-Resour. Investig. Book 6 Chapter A7 77 PGoogle Scholar
  18. Herzberg A (1901) Die Wasserversorgung einiger Nordseebäder. J Gasbeleucht Wasserversorg 815–819Google Scholar
  19. Huisman JA, Bouten W, Ferre TP (2004) Bridging the Gap Between Geophysical Measurements and Hydrological Modelling. AGU Fall Meet Abstr 1:1Google Scholar
  20. Ibrahim K (2009) Etude hydrogéologique de l’aquifère côtier dans la région de Oichili en Grande Comore—Mémoire de Master 2 Université d’Avignon, Université de la Réunion, 62 p. Hydraulique Sans Frontières, ComorosGoogle Scholar
  21. Jacob CE (1950) Flow of groundwater, Engineering Hydraulics H. Rouse. Wiley, New York, pp 321–386Google Scholar
  22. Johnson TC, Slater LD, Ntarlagiannis D et al (2012) Monitoring groundwater-surface water interaction using time-series and time-frequency analysis of transient three-dimensional electrical resistivity changes. Water Resour Res 48:W07506. doi: 10.1029/2012WR011893 Google Scholar
  23. Join JL (1991) Caractérisation hydrogéologique du milieu volcanique insulaire, le Piton des Neiges: Ile de La Réunion. Université Montpellier IIGoogle Scholar
  24. Join JL, Comte JC, Bourhane A (2013) Tests méthodologiques en géophysique en vue de l’implantation de forages d’eau sur l’île de La Grande Comore—Projet Pilote de gestion du service public de l’eau en milieu rural sur l’île de La Grande Comore. 64pGoogle Scholar
  25. Join JL, Coudray J (1993) Caractérisation géostructurale des nappes d’altitude en milieu insulaire, Ile de la Réunion. Géodinamica Acta 243–254Google Scholar
  26. Join JL, Courteaud M, Robineau B et al (1996) The problem of prospecting and development of inland groundwater resources in young tropical volcanic islands. IAHS-AISH Publication International Association of Hydrological Sciences, Kingston, pp 405–411Google Scholar
  27. Join JL, Folio JL, Robineau B (2005) Aquifers and groundwater within active shield volcanoes. Evolution of conceptual models in the Piton de la Fournaise volcano. J Volcanol Geoth Res 147:187–201CrossRefGoogle Scholar
  28. Join JL, Pomme JB, Coudray J, Daesslé M (1988) Caractérisation des aquifères basaltiques en domaine littoral. Impact d’un récif corallien. Hydrogéologie 107–115Google Scholar
  29. Lewis K, Allen JI (2009) Validation of a hydrodynamic-ecosystem model simulation with time-series data collected in the western English Channel. J Mar Syst 77:296–311CrossRefGoogle Scholar
  30. Loke MH (2006) RES2DINV ver. 3.55, Rapid 2‐D resistivity & IP inversion using the least‐squares method, 139 pp., Geotomo Software, Penang, Malaysia,
  31. Marini D (1990) Résultats et interprétations d’une campagne de pompages d’essais sur des puits dans les aquifères de base, Grande Comore. 122 pGoogle Scholar
  32. Massari M (1990) Étude du pouvoir épurateur de divers matériaux de l’Ile de la Réunion vis à vis d’effluents domestiques et industriels. Université de ProvenceGoogle Scholar
  33. Meybeck M, Helmer R (1989) The quality of rivers: from pristine stage to global pollution. Palaeogeogr Palaeoclimatol Palaeoecol 75:283–309. doi: 10.1016/0031-0182(89)90191-0 CrossRefGoogle Scholar
  34. Mohamed I (2012) L’eau en Grande Comore : étude de cas d’un petit espace insulaire abondamment arrosé mais en situation de pénurie d’eau. Université de La Réunion, Thèse de DoctoratGoogle Scholar
  35. Mohamed SH, Othman SA (2006) Etude causale sur la disponibilité de la ressource en eau et la sécurité de l’approvisionnement en eau potable aux Comores (Version finale). Rapport PNUD 16(10/2006):42pGoogle Scholar
  36. Ragot JM (2007) Termes de références pour l’étude des ressources en eaux souterraines de l’Union des Comores. 37pGoogle Scholar
  37. Revil A, Karaoulis M, Johnson T, Kemna A (2012) Review: Some low-frequency electrical methods for subsurface characterization and monitoring in hydrogeology. Hydrogeol J 20:617–658. doi: 10.1007/s10040-011-0819-x
  38. Savin C, Ritz M, Join JL, Bachelery P (2001) Hydrothermal system mapped by CSAMT on Karthala volcano, Grande Comore Island, Indian Ocean. J Appl Geophys 48:143–152. doi: 10.1016/S0926-9851(01)00078-7 CrossRefGoogle Scholar
  39. SCP (2009) Etat des lieux des conditions d’accès à l’eau potable sur l’île de Grande Comore. 49pGoogle Scholar
  40. UNDP (1987) Recherche et mise en valeur des eaux—Rapport technique—Perspectives de mise en valeur des eaux souterraines pour l’alimentation en eau des agglomérations de l’île de Ngazidja. New YorkGoogle Scholar
  41. Vengosh A (2003) 9.09—Salinization and saline environments. In: Editors-in-chief: Holland HD, Turekian KK (eds) Treatise geochemistry. Pergamon, Oxford, pp 1–35Google Scholar
  42. WHO (2003) Total dissolved solids in drinking-water. Background document for preparation of WHO Guidelines for drinking-water quality. (WHO/SDE/WSH/03.04/16). World Health Organization, GenevaGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Anli Bourhane
    • 1
  • Jean-Christophe Comte
    • 2
    • 3
  • Jean-Lambert Join
    • 1
  • Kassim Ibrahim
    • 4
  1. 1.Laboratoire Géosciences RéunionUniversité de La Réunion, Institut de Physique du Globe de ParisLa RéunionFrance
  2. 2.Groundwater Research Group — SPACEQueen’s University BelfastNorthern IrelandUK
  3. 3.School of GeosciencesUniversity of AberdeenScotlandUK
  4. 4.Faculty of Sciences and TechniquesUniversity of the ComorosMoroniUnion of the Comoros

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