2004 Volume 57 Issue 4 Pages 33-38
Large sediment disasters where dead persons reached to 200 persons occurred in December 2003 in Southern Leyte and Northern Mindanao of the Philippines due to heavy rainfall that hit these areas. Most of the casualties were due to the large landslide and the debris flow caused by the heavy rainfall that reached to three times as much as mean monthly precipitation. Especially, the landslide that occurred at San Francisco of Southern Leyte changed to debris flow and deposited huge volume of soil in that area, hitting the houses including the hall where many inhabitants sought refuge after an earlier collapse in a nearby slope. As a result, the number of casualties in this area reached to more than 120 persons. In addition to heavy rainfall, geological structure caused these disasters, because these landslides occurred along Philippines Fault that runs from north to south of Philippines and occurred on the andesite that was weathered and changed to clay. Therefore, there is possibility that sediment disasters occur in this area again. So, it is necessary to inform the people in the dangerous spots for sediment disasters and evacuate them as counter measures to mitigate such disasters.