Earthquake hazards and property damages induced by the Niigata Chuetsu Earthquake in 2004, Whnazu district, Kawaguchi Town, Niigata, Japan

The Niigata Chuetsu earthquake (M6.8) occurred on October 23, 2004. It caused widespread hazards and damages in the Chuetsu area, Niigata Prefecture, which including 46 deaths, house destruction of more than 100,000, a great deal of land deformation and structures. Especially, a seismometer installed in the Kawaguchi Town, where located in the eastern part of the epicenter, recorded seismic intensity of 7. We investigated the earthquake hazards and property damages in the Wanazu district, Kawaguchi Town, and preliminary examined the geomorphological and geological aspects of land on which the houses are situated. Most of properties in this district are situated on four terrace surfaces, flood plain, natural levee and two alluvial fans. The house damages are concentrated on steep slopes of alluvial fans overlying terrace and gently slopes of alluvial fan deposits, and are also comparatively concentrated on terraces in the left bank of the Uono River. On the other hand, the house damages situated on terraces in the right bank of the Uono River are less than on which in the left one. Therefore, it is inferred that ground in the Wanazu district were received strong motion by the Niigata Chuetsu earthquake on the left bank of the Uono River