MEASUREMENT OF GROUND DISPLACEMENTS DURING 1995 HYOGOKEN-NAMBU EARTHQUAKE BY AERIAL PHOTOGRAMMETRY

This paper reports the measurement of permanent ground displacements in Hyogoken-Nambu earthquake arising on Jan. 17, 1995. The measurement is executed over entire Ashiya-city by conventional aerial photogrammetry with photographs on the scale of 1:4, 000. Three-dimensional displacements of about 700 ground points and vertical displacements of about 800 manhole lids are measured by analytical stereo plotters. Estimated measurement precision is 8cm horizontally and 15cm vertically. It is observed that the directions and magnitudes of displacements are closely connected to both distance from the dike and the front water depth there in Ashiyahama reclaimed land.