Banca de QUALIFICAÇÃO: HÉLIO JOSÉ DE OLIVEIRA JÚNIOR

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : HÉLIO JOSÉ DE OLIVEIRA JÚNIOR
DATE: 20/07/2026
TIME: 10:00
LOCAL: Videoconferência
TITLE:

High-Resolution GPR Geophysical Imaging for Subsurface Dam Siting in an Ephemeral  Stream within the Brazilian Semiarid Region

KEY WORDS:

Underground dam; GPR; Brazilian semiarid

PAGES: 46
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUMMARY:

Ensuring water security in semi-arid regions depends on the development of social  technologies tailored to the dynamics of ephemeral streams. This study evaluates the geological and  physical-structural constraints for locating a subsurface dam within the bed of the Cabuji River, at the  Santa Luzia Farm, in the municipality of Angicos, Rio Grande do Norte, Brazil. The study area is  situated within the geotectonic context of the Borborema Province, overlying the crystalline basement  of the Seridó Belt. Due to the predominance of fractured metamorphic rocks and shallow soils, the  region constitutes a geologically unfavorable environment for conventional groundwater accumulation  and storage in deep aquifers. Given this chronic hydrogeological limitation, developing alternative  abstraction and retention technologies is essential to mitigate climate vulnerability and drive local  socioeconomic development. The methodology integrated high-resolution Ground Penetrating Radar  (GPR) imaging for the three-dimensional delineation of the alluvial sedimentary package thickness.  Siting criteria were based on the thickness of the sedimentary package, the narrowing of the river  channel, and the presence of lateral abutments for the structural anchoring of the crest/septon. The  adopted geophysical model allowed the impermeable core to be positioned across the thinnest section  of the alluvium, immediately downstream of a thick upstream sequence of accumulated sediments,  thereby optimizing the consumption of waterproofing material and maximizing the volume of retained  water. In conclusion, although the strong rheological structural control precludes a strictly orthogonal  alignment of the core wall relative to the theoretical flow, the evaluated reach meets the technical  requirements for implementing the Costa & Melo Model, consolidating GPR as an important tool for  enabling shallow reservoirs in crystalline terrains.

COMMITTEE MEMBERS:
Presidente - 1161652 - FRANCISCO PINHEIRO LIMA FILHO
Interno - 1714488 - LEANDSON ROBERTO FERNANDES DE LUCENA
Externa à Instituição - MARIA SÔNIA LOPES DA SILVA - EMBRAPA