A recent publication by the PROTECT Team revealed interesting findings on how drainage features impact groundwater flow in karst aquifers in Northern Puerto Rico. In karst terrains, subsurface conduit networks with unknown characteristics, and surface features (such as springs, rivers, lagoons and wetlands) act as drains for the karst aquifers, thus impacting regional groundwater flow characteristics.

Former PROTECT trainee Reza Ghasemizadeh simulated the drainage effect of conduit networks by incorporated drain lines connecting sinkholes and springs to improve regional modeling. Implemented in an equivalent porous media (EPM) approach, the model with drains is able to reproduce the spring discharge hydrographs in response to rainfall. Hydraulic characteristics of the aquifers are found to be scale dependent.

The study enhances current understanding of the complex flow patterns in karst aquifers and suggests that proper accounting for drainage feature improves modeling where available data on conduit characteristics are minimal. This will also lead to better understanding of the mechanisms and rates at which contaminants move in karst aquifers, and thus the development of better strategies for remediation and minimizing exposures.

Click here to access the full pdf.

Location of study area, wetland, major streams, and land surface elevation data of central NPR