Site characterization of the Pudong watershed within the Upper Amburayan River Basin in Kapangan, Benguet [Philippines]

Pudong River Watershed was characterized in terms of its physical, biological and sociocultural features. It is located in Kapangan, Benguet covering three barangays: Pudong, Sagubo, and Cayapes. It has an area of 2,394.5 ha and lies between 16 deg 35'N to 16 deg 3'N latitude and 120 deg 33'30 to 120 deg 36'30 E longitude. The area is generally hilly to mountainous with very steep slope, rugged and rocky mountain terrain. Elevation ranges from 300 masl to 1,535 masl with four major land uses: agricultural, forested, settlement, and areas not suitable for agriculture. The main soil type is clay loam, sandy loam, and gravelly loam. Runoff at Main Pudong River Lanas Bridge is 2.72 cu m per second. The tributaries runoff range from 0.1 to 0.69 cm. Water quality parameter values are pH (7.21 to 7.84), conductivity (0.072 to 0.580), turbidity (1 to 10 ntu), and dissolved oxygen (8.50 to 9.78). Total suspended solid (TSS) ranges from 6.0 mg/L at the Tabaan Creek to 166.0 mg/L at Kabosol Creek which exceeds the 50 mg/L standard limit for Class A freshwater. Total dissolved solids (TDS) of the Ansuble, Cambali and Leglegan Creek exceeded the standard limit of 1,000 mg/L per DAO no. 34 indicating the presence of inorganic salts. Vegetational analyses in the different land uses reveal a total of 67 Benguet pine trees inventoried with a total volume of 27.1928 cu m. Ficus dominates the riparian zones while pomelo, mango, coffee, star apple and jackfruit dominate the agroforestry area. Diverse understorey vegetation include 52 species in pine forest, 61 species in riparian zones, and 56 species in grasslands. Major agricultural crop planted is rice complemented with vegetables, cassava, corn, tiger grass, pineapple, etc. Wild animal species like Philippine bulbul, owls, mynas, malkoha, rice birds, swiftlets, etc. were also observed. A low level of awareness of the people about forestry and issues/concerns on watershed and environmental management was observed. However, willingness to work for the preservation/protection of the environment and natural resources were noted.