Physical Profile of the Sub-watersheds of Southern Cauayan Municipal Forest and Watershed Reserve in Negros Occidental, Philippines

Abstract

The Southern Cauayan Municipal Forest and Watershed Reserve (SCMFWR) is a 6,000-hectare area in the forests of southwestern Negros in the Philippines. It is part of the Greater Calatong Watershed, which supplies water to farmers in Cauayan and Sipalay City. This study describes the profile of the sub-watersheds within the SCMFWR. The data may be used as basis for management purposes and monitoring of the overall health of the reserve. Specifically, the study delineated boundaries, and drainage areas, classified sub-watersheds, described land use, and determined water discharge of three major river tributaries Cabanbanan, Tinagpito, and Banso and their physical characteristics. The drainage areas of the three rivers were delineated using Topographic Map from the Philippine National Mapping and Resource Information Authority, Google Map, and ASTER GDEM 2011, and secondary data/maps from the Provincial Environment Management Office. DENR manual on watershed characterization was used for the sub-watershed classification. The measurement of water discharge was done by measuring average crosssectional areas of the river and water velocities obtained through the floatation method. Other watershed and river characteristics were gathered by ocular observation. The study determined that SCMFWR is divided into three subwatersheds with a total area of 2944.78 ha. that feeds the three river systems.