Banca de DEFESA: CARLOS WAGNER RODRIGUES DO NASCIMENTO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : CARLOS WAGNER RODRIGUES DO NASCIMENTO
DATA : 14/02/2019
HORA: 09:00
LOCAL: Sala Marcelo Nunes Camargo, n°24, Departamento de Solos
TÍTULO:

Iron Bars as a subsidy to the use of Ground Penetrating Radar (GPR) with monostatic antennas for soil imaging

PALAVRAS-CHAVES:
PÁGINAS: 121
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Ciência do Solo
ESPECIALIDADE: Física do Solo
RESUMO:

NASCIMENTO, Carlos Wagner Rodrigues do. Iron Bars as a subsidy to the use of Ground Penetrating Radar (GPR) with monostatic antennas for soil imaging. 2019. 107f. Dissertation (Master of Science in Agronomy, Soil Science), Agronomy Institute, Soil Department, Federal Rural University of Rio de Janeiro, Seropédica, RJ, Brazil, 2019.

The Ground Penetrating Radar (GPR) is a geophysical tool for the study of soils. However, the reliability of the interpretation of its results depends on the correlation between the geophysical data and the data collected in the field. In the study of the thickness of horizons / layers of soils, or even the thickness of the soil as a whole, a methodology that can collect the speed of the magnetic pulse in the soil to model the depth on radargrams is necessary. However, although there are methods that allow depth modeling, such as the Commom Midpoint (CMP), which is a method that presents better reliability among the methodologies, there is no absolute guarantee of identifying the correct depth of the target due to several factors, such as the presence of noise. In addition, the CMP technique is restricted to GPR models with bi-static antennas. Thus, this work aimed to investigate in which physical, chemical and morphological conditions the use of iron bars can help in the identification of the depth of soil horizons using GPR. This study was developed at Fazendinha Agroecológica Km 47 (Sistema Integrado de Produção Agroecológica - SIPA) that is part of  Embrapa Agrobiologia, Empresa de Pesquisa Agropecuária of Rio de Janeiro state (Pesagro-Rio) and of the Universidade Federal Rural do Rio de Janeiro. For this, iron bars were inserted in the transitions of the horizons in ten soil profiles (four Planossolos Háplicos, one Gleissolo Háplico, three Argissolos Vermelhos, one Argissolo Amarelo and one Cambissolo Háplico) exposed in trenches and investigated with a GPR with two monostatic shielded antennas (450 and 750 MHz), with further processing of the radargrams. As results, the 450 MHz antenna produced radargrams sharper than those of the 750 MHz antenna, and the hyperboles generated by the iron bars in the radargram were more visible in sandy soils, especially those ones that have transitions between sandy to clay horizons. In addition, iron bars could be identified in clayey soils under specific conditions. The calculated magnetic pulse velocity had more constant values along the vertical section of the radargrams generated by the 450 MHz antenna in sandy soils than in clayey soils, possibly because the hyperboles were more visible in sandy soils. It is concluded that the iron bars are efficient for the immediate distinction of the transitions between horizons with a clear difference in physical properties, as is the case of the transition from sandy horizons to clayey ones.

MEMBROS DA BANCA:
Externo à Instituição - GUSTAVO DE MATTOS VASQUES - EMBRAPA
Interno - 1060711 - MARCOS GERVASIO PEREIRA
Externo à Instituição - WENCESLAU GERALDES TEIXEIRA - OUTRO