Isotopic composition in precipitation and groundwater in the northern mountainous region of the Central Valley of Costa Rica.
The linkage between precipitation and recharge is still poorly understood in the Central America region. This study focuses on stable isotopic composition in precipitation and groundwater in the northern mountainous region of the Central Valley of Costa Rica. During the dry season, rainfall samples corresponded to enriched events with high deuterium excess. By mid-May, the Intertropical Convergence Zone poses over Costa Rica resulting in a depletion of18O/16O and2H/H ratios. A parsimonious four-variable regression model (r2= 0.52) was able to predict daily δ18O in precipitation. Air mass back trajectories indicated a combination of Caribbean Sea and Pacific Ocean sources, which is clearly depicted in groundwater isoscape. Aquifers relying on Pacific-originated recharge exhibited a more depleted pattern, whereas recharge areas relying on Caribbean parental moisture showed an enrichment trend. These results can be used to enhance modelling efforts in Central America where scarcity of long-term data limits water resources management plans.
a Chemistry Department, Stable Isotope Research Group , National University of Costa Rica , Heredia , Costa Rica.
Ricardo
R
Sánchez-Murillo
a Chemistry Department, Stable Isotope Research Group , National University of Costa Rica , Heredia , Costa Rica.
Germain
G
Esquivel-Hernández
a Chemistry Department, Stable Isotope Research Group , National University of Costa Rica , Heredia , Costa Rica.
Oscar
O
Sáenz-Rosales
b Chemistry Department , National University of Costa Rica , Heredia , Costa Rica.
Gilberto
G
Piedra-Marín
c Environmental Hydrology Laboratory, Biological Sciences Department , National University of Costa Rica , Heredia , Costa Rica.
Alicia
A
Fonseca-Sánchez
c Environmental Hydrology Laboratory, Biological Sciences Department , National University of Costa Rica , Heredia , Costa Rica.
Helga
H
Madrigal-Solís
d Departamento de Recurso Hídrico , Empresa de Servicios Públicos de Heredia S.A., UEN Agua Potable e Hidrantes , Heredia , Costa Rica.
Franz
F
Ulloa-Chaverri
d Departamento de Recurso Hídrico , Empresa de Servicios Públicos de Heredia S.A., UEN Agua Potable e Hidrantes , Heredia , Costa Rica.
Luis D
LD
Rojas-Jiménez
d Departamento de Recurso Hídrico , Empresa de Servicios Públicos de Heredia S.A., UEN Agua Potable e Hidrantes , Heredia , Costa Rica.
José A
JA
Vargas-Víquez
D003364:Costa Rica; D003903:Deuterium / Q000032:analysis; D004784:Environmental Monitoring; D060587:Groundwater / Q000737:chemistry*; D008962:Models, Theoretical; D010103:Oxygen Isotopes / Q000032:analysis; D011891:Rain / Q000737:chemistry*; D012621:Seasons
D010103:Oxygen Isotopes; D003903:Deuterium
Costa Rica; air mass back trajectories; deuterium excess; groundwater management; hydrogen-2; isotope hydrology; oxygen-18; precipitation