Abstract
One of the big themes for forecasting the occurrence of slope land disaster is to predict “where”, “in what scale” and “when” such disaster may take place. When the theme “where”among them is to be discussed, it is general practice to analyze the factor of occurrence.
The analysis of occurrence factor can be roughly classified into the case where it is grasped as a “point” from a viewpoint of “where the disaster took place”, and the case where it is grasped and analyzed as a “surface”from a viewpoint of “in what scale the disaster took place”. In case when the analysis is made from the viewpoint of “where the disaster took place”, the occurring area, sliding area and piling area are all represented by one point, and all of them are treated as an average factor. Therefore, it is impossible to adequately analyze “under what conditions of land the disaster took place”. Similarly, the discussion on “under what conditions of the land”is not sufficient in case where the disaster is analyzed from the viewpoint of “in what scale it took place”.
When we deeply analyze the occurrence factors, it is essential to analyze the case from the viewpoint of “under what conditions of land the disaster took place”. In that case, it is important to analyze the head cleavage or sliding cliff of land slide as a line. For this purpose, it is effective to use the overlay method of images with the unit of pixel of some proper size as the analysis method.
In this study, we report the idea of method to analyze the factors of place of slope land disaster as the “line” through the digital image analysis of aerial photograph data.
