Groundwater vulnerability and risk mapping using GIS, modeling and a fuzzy logic tool

Area of Science:

• Hydrogeology
• Environmental Science
• Water Resource Management

Background:

• Urban coastal aquifers are vital water sources but susceptible to contamination.
• Assessing groundwater vulnerability and risk is crucial for effective water resource management.

Purpose of the Study:

• To conduct a groundwater vulnerability and risk mapping assessment for an urban coastal aquifer in northeastern Brazil.
• To identify priority areas for groundwater monitoring and use restrictions.

Main Methods:

• A modified DRASTIC methodology was employed to map intrinsic and specific groundwater vulnerability.
• Fuzzy hierarchy methodology evaluated potential contaminant source index (diffuse and point sources).
• Numerical modeling (MODFLOW, MODPATH) delineated well capture zones.

Main Results:

• Integrated assessment identified groundwater pollution risks.
• Specific vulnerability index showed a positive correlation with a groundwater quality index (nitrate and chloride).
• Prioritized areas for groundwater management were delineated.

Conclusions:

• The source-pathway-receptor approach effectively integrated vulnerability and risk assessment.
• The methodology provides a robust framework for managing groundwater resources in similar urban coastal environments.
• Findings support informed decision-making for sustainable groundwater use and protection.