Deep groundwater flow as the main pathway for chemical outputs in a small headwater watershed (Mule Hole, South India)

Jean-Christophe Maréchal (1, 2, 3) , Jean Riotte (2, 3) , Christelle Lagane (2) , S. Subramanian (3, 4) , C. Kumar (3) , Laurent Ruiz (5) , Stéphane Audry (2) , Mrr Varma (3) , J.J. Braun (2, 3)

1 BRGM - Bureau de Recherches Géologiques et Minières (BRGM)
2 GET - Géosciences Environnement Toulouse
3 IFCWS - Indo-French Cell for Water Sciences
4 Department of Materials Engineering
5 SAS - Sol Agro et hydrosystème Spatialisation

This study examined the water and chemical cycles of a small forested head catchment. Application of Cl mass balance lead to the identification of a groundwater baseflow located into the active zone of the crystalline aquifer, below the weir. These findings indicate that groundwater contributes to a large part of chemical outputs at the catchment scale. This study shows that groundwater should not be ignored in most small watershed studies because this flow path and associated solutes are strongly significant for chemical balance assessment.

Mots clés: weathering rate; hydrogeology; mass balance; solutes; crystalline aquifer; chemical balance; chloride mass balance

Domaines: Hydrologie; Milieux et Changements globaux

Jean-Christophe Maréchal, Jean Riotte, Christelle Lagane, S. Subramanian, C. Kumar, et al.. Deep groundwater flow as the main pathway for chemical outputs in a small headwater watershed (Mule Hole, South India). Applied Geochemistry, 2011, 26 (S), pp.S94-S96. ⟨10.1016/j.apgeochem.2011.03.039⟩. ⟨hal-00662847⟩