Geophysical information measurements have been used successfully to delineate conductive, resistive target inhomogeneities and to determine the characteristics of geological structures, such as water bearing zones, faults, massive bodies, and other complicated environments.
Unfortunately, surface methods do not work well for local target inhomogeneities and for area having conductive overburdens.
Recently, computer modeling has been performed more easily in conjunction with the field geophysical measurements. And three-dimensional modeling has been often utilized to simulate the geological target inhomogeneities. Of course, in the study of borehole geophysical information measurements, a computer three-dimensional modeling has been effectively conducted for forward models of various conditions and theoretical interpretation.
This paper begins with a brief review about a trend and new activities of geophysical information measurements. Next, the examples of borehole electrical methods have been chosen to demonstrate the typical apparent resistivity curves and pseudosections for pole-pole, pole-dipole and dipole-dipole arrays using single hole, hole-to-surface and cross-hole. In addition to demonstrate the pseudosections, the extraction and enhancement of geophysical information due to the target inhomogeneities have been discussed from three points of view using the three-dimensional prospecting models.

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The Ooya-Ishi pumice tuff have been quarried extensively for building materials. However, most of non working quarries have been left unfilled (large cavity) . Consequently, the strength of the rocks has degraded as a result of weathering and release of underground stress.
Our observation confirmed that field acoustic emission increased at the sites of partially degraded tuff. Further, the above observation enabled the prediction of ground sinking at two sites.
In view of the above, a geotechnical information database system was compiled in order to facilitate precise and timely observation. The database system has been extremely usefull for analysis of field acoustic emission.
The salient features of the database system are as follows;
(1) The database system is composed of two elements, namely the data management sub-system and the application sub-system.
(2) Data search capability based on keywords.
(3) Generation of three dimensional vector and grided maps using digital data.
(4) Display of reduced scale three dimensional maps.
(5) Capability to superimpose field acoustic emission data on any three dimensional map.

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