Banca de DEFESA: RENILDA FATIMA GONÇALVES DE LIMA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : RENILDA FATIMA GONÇALVES DE LIMA
DATA : 26/07/2019
HORA: 13:00
LOCAL: Auditório Yeda
TÍTULO:

Hidrogeologia e Vulnerabilidade do Aquífero Cárstico Salitre, na Bacia Una-Utinga, Bahia

PALAVRAS-CHAVES:

Vulnerability. Karstic Index. Hydrogeology. Una-Utinga Basin. Salitre Aquifer

PÁGINAS: 192
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
SUBÁREA: Geologia
ESPECIALIDADE: Hidrogeologia
RESUMO:

The Una-Utinga Basin (UUB), located in the central region of the Bahia state, houses an important karstic aquifer system, corresponding to the Saltpeter Formation, which carbonate rocks date from the Neoproterozoic and are divided into Gabriel/Nova América Unit and Nova América sub-unit Lapão. This work aims to present a hydrogeological characterization pioneer for the area, with a view to the hydrochemical, isotopic, of transmissivity and vulnerability issues of the Salitre aquifer in the UUB. For the hydrochemical, it was used chemical data from 35 tubular wells, collected in the area, analyzed in LEPETRO/UFBA, and 17 samples from the CERB database. The isotopic analysis was done from samples collected in 36 wells and performed in the Laboratory of Nuclear Physics/UFBA. The transmissivity was calculated by the analytical method of Theis and empirically recalculated by statistical analysis. For a better response of vulnerability mapping, it was necessary to obtain a surface karsification index previously, made from the mapping of dolines density and structural lineaments. Finally, the vulnerability was evaluated through the methods COP and PI, in order to make a comparison of their applications in the UUB. As results, 58% of bicarbonated water, 23% chlorinated, 13% mixed and 6% sulfated were obtained as water typology, Regarding potability, the analyzed parameter was salinity and 48% of the waters from the sweet wells, 33% brackish and 19% salted were obtained. In relation to the isotopes, the samples were divided into two groups of distinct signatures, when compared δ18O and STD mg/L. For transmissivity, the response was given as a potentiometric map of the UUB, which general flow of the waters of the Salitre aquifer tends to the west. The karst index generated a predictive map of features of the exocarste and divided the area into karsification classes. The areas with a high rate of karsification were called karst islands and were used differently in the assessment of vulnerability. These islands, for the most part, are conditioned to the occurrence of the Nova América sub-unit Lapão. The vulnerability assessment using the COP method presented 5 classes of vulnerability, while the PI 4. The greater area coverage in both methods corresponds to the low vulnerability class. The lithology and surface karstic features were shown to be more influential factors in the determination of vulnerability in both methods. In view of this range of analyzes it was concluded that (i) the typologies, ionic ratios and potability tend to follow the regional underground flow in the UUB; (ii) the transmissivity spatial model shows the area of greatest potential in the western portion of the UUB; (iii) the application of the karstic index revealed excellent acuity in the expression of the surface features of the karst system; (iv) the COP vulnerability method presented a more compatible response with the characteristics available to the UUB; (v) the combined analysis of the hydrogeological parameters and vulnerability demonstrated the compatibility among the karst islands (high vulnerability) and the greater spatial potentiality of the aquifer. Thus, it is necessary to pay greater attention to these areas in view of the high susceptibility to contamination of the Salitre aquifer. This research will fill a gap in the hydrogeological knowledge of karstic domains and their environmental management in the state of Bahia.

MEMBROS DA BANCA:
Externo ao Programa - 2564681 - CRISTOVALDO BISPO DOS SANTOS
Presidente - 2298240 - LUIZ ROGERIO BASTOS LEAL
Externo ao Programa - 3071908 - MARIA DA CONCEICAO RABELO GOMES
Externo ao Programa - 2349838 - MARIA DO ROSARIO ZUCCHI
Interno - 031.086.865-34 - SERGIO AUGUSTO DE MORAIS NASCIMENTO - UFBA