VULNERABILITY ASSESSMENT OF FRACTURED AQUIFERS USING COP AND DRASTIC

ABSTRACT: Groundwater is one of the important water resources in any country especially when it is used for drinking purposes. Unfortunately, the lack of sufficient attention has caused irreversible damages to some aquifers around the world. It is important to protect this resource using preventive means and methods. Aquifer vulnerability assessments can help decision-makers to decide where to invest more in the protection of aquifers and where there is natural protection. Aquifers do not respond rapidly to contamination and it makes the vulnerability assessment methods an important tool that can be utilized to prevent aquifers from being contaminated. Many regional fractured bedrock aquifers represent important sources for drinking water across Canada. There are different vulnerability assessment methods for this type of aquifers, but they are mostly applied on karstic aquifers. A common method for vulnerability assessment of fractured bedrock aquifers is COP. On the other hand, the DRASTIC method has been used widely on aquifers including overburden and fractured bedrock aquifers. Both methods are a subgroup of methods under qualitative / index-based vulnerability methods. In these methods, the vulnerability index is calculated based on an indicator selection and aggregation methodology and delivers a single numerical result. To assess the performances of both methods, a quality parameter is used to validate these methods.