Investigações ambiental e forense com os métodos geofísicos radar de penetração do solo, polarização induzida e eletrorresistividade no Cemitério do Tapanã, Belém/Pará

Abstract

The cemeteries are considered potential sources of underground water contamination. Since the use of geophysics in the mapping of the hydrostatic level (HL) has become a very important tool in the environmental monitoring, it makes possible to verify adequate or inadequate areas for burials in cemeteries. In the other hand, the localization of underground clandestine hollows and tunnels, can be of utility for the Forensic Science. In this work, geophysical methods were applied for mapping the HL in a cemetery and to find buried structures related to the Forensic Science. Ground Penetrating Radar (GPR) was used in the mapping of the HL in the whole Tapanã cemetery, while the resistivity and induced polarization (IP) methods were applied on a test site built in that cemetery for forensic, environmental and resgate related geophysical studies. The results with the GPR showed that the HL depth in the Tapanã cemetery varies from 7 m, at high topographic levels, to 1 m, at low topographic levels. The IP was sensible to the presence of a body buried in a shallow hollow as the clandestine hollows are and showed only fair results for a tunnel. The resistivity was effective for both the buried body and the tunnel, with better definition of the tunnel. The methods gave good results even within the weathering layer rich in clay that normally occurs in the Amazon region.