Risk assessment of water quality using probability-consequence analysis and geospatial interpolation

ABSTRACT Risk analysis is widely recognized for its simplicity and effectiveness in identifying and categorizing potential threats. It is based on two essential criteria, probability and consequence, allowing for risk prioritization and the adoption of preventive measures. In this context, the present study applies the Probability and Consequence (P&C) analysis methodology, combined with geospatial interpolation, to assess water quality and ensure water security in the municipality of Conceição do Araguaia, Pará. To achieve this, the methodological steps included parameter identification, on-site sampling, risk quantification, geostatistical modeling, and cross-validation. The results identified 19 sampling points classified between high and critical risk. The validation analysis revealed high local heterogeneity, indicating that micro-local factors drive contamination. Despite this variability, the map proved effective in identifying macroscopic zones of vulnerability, optimizing resource allocation by focusing inspections on critical clusters. The analysis showed that pH, nitrite, total coliforms, and E. coli were the main risk factors in the studied region. Thus, this study contributes to strengthening water security by proposing a zonal management approach, providing support for implementing preventive strategies to protect water resources and public health.