Correlação Espacial do Alto Teor de Ferro na Água Subterrânea dos Aquíferos Sedimentar e Metassedimentar do Estado da Bahia e os atributos, Clima, Pluviometria e Litologia

This paper presents a spatial correlation between the high iron content in groundwater from the sedimentary and metasedimentary aquifers of the State of Bahia, and the attributes climate, rainfall and lithology, for wells drilled in the period 2003-2013 with flow test ≥ 1m³/h. In the sedimentary rocks domain, from 494 samples, 152 (30.8%) presented high iron content, while in the metasedimentary rocks domain, from 675 presented high iron content 227 (33.6%). High levels of iron limit the use of groundwater for human consumption, especially in regions where there is no economic condition to perform the treatment for iron removal permanently. Therefore, understanding the distribution of high iron content in these aquifers and its correlation with the attributes, climate, rainfall and lithology is useful for the best prospecting of this resource. The results obtained in sedimentary aquifers show that the higher the rainfall range and the predominance of the humid, and humid to subhumid climate, the higher the percentage of wells with high iron content. As for the metasedimentary aquifer, with climate subhumid to dry, and semiarid, and reasonably close rainfall averages per sections of the domain, the presence of iron-producing rocks better explained the higher percentages of wells with high-iron content.