Uso de sensoriamento remoto para avaliação do potencial hidrogeológico do município de Aurora-CE

Abstract

Groundwater is the portion of water that is stored in any quantity below the surface of the earth. These waters fill fractures, faults and pores of rocks, forming different types of aquifers. This resource is extremely important for the water security of the region where it is located, acting directly in the social and economic development of the local population. In Brazil, most of the groundwater is extracted by tube wells (artesian and semi-artesian), which are normally distributed for domestic, industrial and agricultural supply. In the semi arid regions of northeastern Brazil, where the municipality of Aurora is located, due to irregular rains, dry periods, the climate and other characteristics, the use of groundwater becomes an important factor to help fight drought, mainly as an alternative for human and animal supply. Therefore, the objective of this work was to evaluate the hydrogeological potential of the municipality of Aurora in the state of Ceará through remote sensing techniques. The work was developed in two stages, the first stage of the research comprised the construction of a georeferenced database, using IBGE files, related to the geology and hydrography of the municipality of Aurora; CPRM data, referring to tubular wells registered in SIAGAS; SRTM and MDE images from the USGS digital repositories. From this, the second phase was developed with the processing of these data in a GIS environment, using the QGIS software, in which it was possible to generate thematic maps, in which, their analyzes allowed the classification in a qualitative way, referring to the potential of occurrence of groundwater in the studied region. For this purpose, the two highest flow wells registered in SIAGAS were selected for detailing, called wells A and B, with specific flows of 18.75 m 3 /h/m and 0.68 m 3 /h/m. In view of this, it was verified that the area of occurrence of well A presented favorability for the occurrence of groundwater due to the identification of a crevice stream in the area that, probably, favored the formation of an aquifer with good capacity to accumulate groundwater. . On the other hand, well B, located between two directional tailings faults, recorded a low specific flow, which could possibly be associated with low secondary porosity of the fissure aquifer in the area. Thus, from the studies of the areas, it is recommended to carry out geophysical surveys as a complement to the study of the favorability of the areas, which are of great importance for the success in the definition of locations for the drilling of wells.