Application method of satellite remote sensing for engineering geology were examined. Literature survey revealed the present condition of application of remote sensing for engineering geology. Two examples were studied on the bassis of literature survey. One was the study of identify of lineaments using remote sensing data, while the other was the prediction of landslide. 1) To identify of lineaments: The lineaments which were identified through interpretation of LANDSAT TM images were coincide with those identified through aerial photographs. It was found more effective to survey lineaments using both data. 2) To predict landslides: The regions suspectible to landslide were predicted using LANDSAT TM data and digital geographic information. Land cover classification data and vegitation index were caluculated from remote sensing data. It was confirmed more effective to predict the regions suspectible to landslide.
In this study, we clarified the factors which highly relate to the occurrence of collapse by jointly applying the image overlay method and quantification method on the places where the collapse occurred at the surface layer in the past. We also discussed the necessity to analyze the hazardous places where the collapse is anticipated occurring at the surface layer in the future, respectively for each pattern of occurrence. We could obtain the following findings through this study: (1) The collapses in the study area caused by the same reason (124 places) could be roughly classified into 6 patterns. (2) By employing the analysis method with which image overlay method and quantification method were jointly used, we were able to surmise the relation between the location of past collapses and hazardous places where the collapse is anticipated in the future.
Presently in the fields of civil engineering and resources development engineering, it is an important theme to grasp precisely existence of underground fractures or sheared faults. In development of geothermal resource, it is neccesary to estimate mechanism of heat and water supply in a wide area, and scale and shape of a geothermal reservoir in the area. In order to estimate potentiality of geothermal energy as hydrothermal convection system, it is important to know permeability of the geothermal reservoir. In the case of a fracture-type geothermal reservoir, existence of fracture system in which geothermal fluids flow or are reserved must be paid attention. Therefore it is important to judge superior directions of fracture system. In this study, it is tried to illustrate superior directions of fracture system on which permeability of geothermal reservoir depends, by the technique for making clear relations between geothermal wells based on pressure interference tests carried out in certain geothermal district and displaying them as parallel projected graphic pictures. If such visual information is combined to other analytical results, more accurate estimation and reliable results can be obtained.
Examination of microcracks by image processing, including pattern recognition and image analysis, is becoming popular in applied geology. In the case of image processing, microcracks in rocks are usually recognized by apparent features, such as differences in brightness, color and/or pattern.On microscopic examination, it is usually difficult to distinguish microcracks from the other elements.The fluorescent method was devised recently to visualize microcracks and cavities in rock and concrete specimens. This method is useful for image processing because images recorded by a CCD camera under ultraviolet ray display a great difference of brightness between microcracks and other texture. We tested five techniques of image processing, linear differential operator (Sobel operator), quadratic differential operator (Laplacian operator;matrix size=3×3 or 9×9), and template matching operator (Kirsch operator and line detection operator), to extract microcracks in weathered granite and andesite fractured by uniaxial compression test retreated by fluorescent method.Actual microcracks in specimens of weathered granite were represented most realistically by thinned binary image obtained by Laplacian operator (matrix size=9×9). Image analysis of microcracks in specimens of andesite fractured by uniaxial compression test was also performed. The results revealed that two types of microcracks, tensile cracks parallel to major principal stress and shear cracks inclined to major principal stress, were extracted.It was also demonstrated that parallel microcracks were formed mainly in groundmass, while inclined microcracks were present mainly in phenocrysts.
Mt. Unzen, located in Nagasaki Prefecture, erupted first in 17th November 1990, and has been active ever since. During its activity, pyro-clastic flows originated from growth and depression of lava domes and debris flows caused death and severe damage in the populated area. In this study, since the surveying area is under dangerous condition, there is great difficulty to keep observation sites in the damaged area. Thus, it is indeed valuable to use remote sensing method for monitoring of active volcanos. The use of aerial photographs taken at eleven different stages of volcanic activity enabled the easy comparison of geomorphological characteristics and volume calculation of volcanic products. Such continuous aerial surveying will be effective to estimate investigation of disaster prevention.
Borehole television, as one of investigation techniques with visual image, is used to investigate borehole walls as a continuous man-made outcrop, and to recognize in-situ rock mass conditions. It has been utilized as an useful method to analysis slope stability and to predict behavior of large rock cavern. Borehole image processing system (BIP System), as of the borehole television method, has been developed owing to the rapid advancement of microprocessors and other electronic devices, which can present images of borehole walls directly as digitized color signals at sites. This paper describes an unique technique of image processing in BIP System, and presents some case histories of detecting discontinuities in rock masses automatically using common method for image recognition.Future view of image processing technique for geological informations are also discussed