Physical Profile of Calbiga River, Samar, Central Philippines

摘要

Physical profile is significant reference to in addressing areas at risk due to fluvial processes and in establishing the physiographic maps especially in protected areas. Calbiga is one of the major rivers inside the Samar Island Natural Park (SINP). The source of Calbiga river was traced at the foot of Mt. Huraw of San Jose de Buan, Samar. The area is at the center of the Samar Island with an elevation of 850 meter above sea level (MASL). The river stretches 36.4 kilometers, with an average span of 44.57 meters, and average depth of 2.6 meters. The average height of the river bank is 7.67 meters, with rage of 5 - 10 meters. Generally, the substrate was sand. On fluvial dynamics, the average water velocity is 0.20 mps with the average water flow of 18.64 m3/sec. The floodplain ranged from 10 - 15 meters and 5 to 7 meters high. The river control measures are making a positive impact, though it could be reviewed to address the low elevation of the midstream. Rehabilitation measures at the watershed should be considered, parallel to the policy implementation of Disaster Risk Reduction Management (DRRM) measures.