VULNERABILITY ASSESSMENT OF SEAWATER IN COASTAL AQUIFERS USING GALDIT METHOD: COASTAL STRIP OF SÃO LUÍS – MA - BRAZIL

• Autor(a) principal: Castro, Renata Maria Sousa
• Data de Publicação: 2022
• Outros Autores: Pereira, Ediléa Dutra, de Oliveira, Manuel Mendes
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Caminhos de Geografia
• Texto Completo: https://seer.ufu.br/index.php/caminhosdegeografia/article/view/60399
• topic: Estudo Hidrogeológico; Disponibilidade Hídrica; Gestão De Exploração; Água Subterrânea; Hydrogeological Study; Groundwater Availability; Exploitation Management; Groundwater

The city of São Luís is influenced by the tides, which leads to the formation of a saline wedge within the rivers characterized by the presence of mangroves in the fluvial-marine plain. The large exploitation of groundwater combined with these physical characteristics increases the risk of salinization reaching aquifers. This work has as main objective to assess São Luís coastal aquifer potential vulnerability to marine intrusion using the GALDIT method. After analysis of the lithological and hydrodynamic characteristics of tubular wells, two main aquifers were identified: Itapecuru, which presents semi-confined behavior, and Barreiras phreatic aquifer. Through vulnerability mapping it was observed that areas with either the largest number of tubular wells or the highest population density showed medium and high vulnerability, especially when closer to the coastal strip. The parameters that most influenced the index were parameter L (piezometric level) and parameter D (distance from the coastline). These results indicate the need of monitoring tubular wells and the urgent application of effective management in the exploitation of groundwater for the maintenance and conservation of fresh water in Maranhão Island.