Suitability Philips Infiltration Model for Surface Runoff Prediction Using Curve Number Method

The objective of this study was to determine suitability and applicability of the Philips infiltration model for predicting surface runoff using the Curve Number method. The data of infiltration rate obtained from direct measurements in the field on a variety of land use in the upper Progo sub watershed using double ring infiltrometer method. Soil samples also taken for determination of physical properties at each location of infiltration measurement. Data of landuse, rainfall, and river discharge were collected from the available data at Balai PSDA Progo Bogowonto Luk ulo and BP DAS Serayu Opak Progo. Test results showed that Philips infiltration model was suitable for predicting surface runoff using curve number method. The suitability was examined by significancy of deterministic coefficient, correlation coefficient, the mass balance, and the distribution of t.