Numerical Model of Aquifer Nimboyores Guanacaste Costa Rica

Due to population growth, tourism, and demand growth for underground water due to human consumption in the coastal area of the canton of Santa Cruz, Guanacaste, Costa Rica, communities in the coastal area showed concern about tourism sector development, due to the shortage of water resources, primarily with the free use of the aquifer Nimboyores. Because of these concerns and the lack of scientific knowledge about the availability of water resources in the area, there is a need for a better understanding of the Nimboyores aquifer status, through a numerical model based on a conceptual model preset.

In Guanacaste, the resources levels of water reception are affected by dry periods of a duration of six months, which coincide with the period of greatest demand for tourism, and the uncontrolled growth of urban settlements, the deterioration in the protection of recharge areas, aquifers overexplotation and land misuse in some areas which has affected water availability and continuity.

Using a three-dimensional finite difference model, a simulation was made in a steady status flow model for coastal underground water aquifer. In this study the modeling software MODFLOW version 2.8 was used, which is a underground water modeling program that can be built and equipped according to the practical applications.
Model calibration was used to predict underground water flow pattern, the interaction between underground water and surface water, and the effect of pumping from wells on the ground in different scenarios.

Guanacaste province is facing water resources shortage and pollution. Underground water is the main resource of water for agriculture industry and domestic use. This study has laid the foundation for the underground water predictive model development, that can be easily used for practical management of this resource, and thus take actions to develop better planning of water resources and their proper protection.