Aplicação do método GOD e DRASTIC na análise de vulnerabilidade natural do Sistema Aquífero Serra Geral no município de Chapecó-SC

Abstract

The present study aimed to assess the vulnerability to natural contamination in the Serra Geral Aquifer System in Chapecó – SC, combining the GOD (Groundwater hydraulic confinement, Overlying strata, Depth to groundwater table) and DRASTIC (Depth to water table, net Recharge, Aquifer media, Soil media, Topography, Impact of vadose zone, hydraulic Conductivity) methodologies. Both approaches were jointly applied to develop vulnerability assessment models, allowing for a comparative analysis of their results. During the research, parameters for each method were determined, and resulting models were validated and integrated into aquifer evaluation techniques. This facilitated the identification of advantages and drawbacks of each approach. The GOD method, simpler with only three parameters, eased data acquisition from the SIAGAS database. Conversely, the more complex DRASTIC method, considering seven parameters, provided a more detailed analysis, requiring more specific information not always available in the mentioned database. Results revealed vulnerability patterns in the studied area. The GOD analysis indicated low vulnerability in most of the region, while the DRASTIC method classified the majority of the territory as medium vulnerability. Chapecó's urban zone was identified as highly vulnerable by both methods, with DRASTIC indicating high vulnerability and GOD showing varied indices between low and high. These outcomes highlighted the sensitivity of urban areas to contamination risks, emphasizing the need for continuous monitoring and implementation of preventive measures to preserve aquifer quality. The study's conclusion underscores the importance of selecting an approach tailored to local characteristics and specific vulnerability assessment goals. The combination of GOD and DRASTIC methodologies allowed for a detailed analysis of contamination vulnerability in the Serra Geral Aquifer System in Chapecó. The choice between these approaches should consider data availability, evaluation objectives, and hydrogeological characteristics of the region. This integrated approach offers crucial insights for sustainable management of underground water resources, contributing to preserving water quality in this significant aquifer area.