Landslides and Landscape Change Induced by Heavy Rainfall and Intensive Earthquake in Mid-Niigata, Japan: GIS Analyses and Interpretation of Aerial Photographs

摘要

In 2004, two big triggering mechanisms (heavy rainfall on July 13 and intensive earthquake on October 23) brought about numberless landslides and remarkable geomorphic changes in hilly terrains composed of considerably folded and faulted Neogene sedimentary rocks. Using GIS, we have analyzed the distribution characteristic of the two landslides and compared between the two landslides. As the results, we have revealed the relationship and the comparison between the two landslides distribution and the topography and geology.Most of the gentle slopes of the Mid-Niigata terrains have been mostly used for paddy fields and ponds. In order to reveal the relationship between the two events and such landuse, we are analyzing the change in landscape, the damage on paddy fields, the pattern of destruction of ponds and occurrence of landslides in GIS using various techniques and inputs. The use of high resolution aerial photographs and LiDAR data are especially useful to classify paddy fields and ponds.