Abstract
Severe rainfall from mid-November to early December 2004 triggered numerous sediment disasters and flashfloods on the eastern coast of Luzon Island in the Philippines, resulting in extensive damage to life and property. Among the affected areas, the coastal towns of Quezon Province suffered the most damage, with numerous landslides occurring in the town of Real and debris flows burying the towns of Infanta and General Nakar. This paper outlines the observations from reconnaissance works conducted at the affected sites following the disaster, with emphasis on the hydro-geological aspects of the disaster and its impact on civil engineering structures and other infrastructures. Moreover, the results of unsaturated-saturated seepage analyses conducted to investigate the mechanism of the collapse of one of the slopes which resulted in death of more than 100 people is presented.
