In relation to weathering and landslides in Japan, the author disccussed the inter-relationships between permeation of ground water controlled by geologic structure, petrological characteristics and geochemical factors which stimulate the weathering. The landslide types are classified from the geological standpoint and weathering characteristics.
The authors disscussed here the pattern of the surface movements of the Yatsugawa Landslide in Tochio city, Niigata Prefecture based upon a series of triangulations which had been carried on five times from May '67 to November '69 purposed evaluation of measurements by photogrammetric method. The pattern of surface movement of the landslide mass during the period are tabulated on Table 1 and illustrated on Figure 2.