WTF and numerical flow simulation methodologies to groundwater recharge estimation – example of Rio Aquifer in Paulínia/SP

Published
2018-05-09
DOI: https://doi.org/10.14295/ras.v32i2.28943
Keywords: Groundwater recharge. Rio Claro aquifer. Numerical flow simulation. Water table fluctutation. Aquífero Rio Claro. Simulação numérica de fluxo. Flutuação do nível d’água. Recarga.

    Authors

  • Elias Hideo Teramoto Centro de Estudos Ambientais - UNESP, Campus de Rio Claro
  • Hung Kiang Chang Departamento de Geologia Aplicada, UNESP - Campus de Rio Claro

Abstract

The estimative of groundwater recharge volume of is a crucial requirement for the management of subsurface water resources. A portion of the Rio Claro aquifer in the municipality of Paulínia/SP is marked by the uncertainties related to geological heterogeneities, the presence of hydrocarbons in the residual phase and the influence of pumping wells of the active remediation systems. As a result of these factors, reasonable recharge estimations are hampered. In order to overcome the mentioned difficulties, numerical simulations of transient flow were carried out to estimate recharge in a portion of the Rio Claro aquifer in the municipality of Paulínia/SP. Since the hydraulic head variations of the simulation are similar to the variations in all wells monitored during the simulated 7 years (2007-2014), this model was considered representative. The comparison of recharge estimation provided by the WTF (water table fluctuation) method and the mathematical model values showed high discrepancies between both. These discrepancies are associated to the difference in the values used for the specific yield parameter in both methods. The results of the present work suggest that the values of Sy and the recharge estimates can promote overestimations in the rates of recharge of the aquifer because it does not contemplate the effect of the hysteresis during the water table fluctuation.

How to Cite
Teramoto, E. H., & Chang, H. K. (2018). WTF and numerical flow simulation methodologies to groundwater recharge estimation – example of Rio Aquifer in Paulínia/SP. Águas Subterrâneas, 32(2), 173–180. https://doi.org/10.14295/ras.v32i2.28943