Aplikasi Model IFAS Untuk Membandingkan Debit dari Tiga DAS (Studi Kasus: Kabupaten Boyolali dan Klaten Jawa Tengah).

Abstract

River discharges influenced by watershed characteristics and nature of precipitation that falls within the catchment area. The amount of discharge can be calculated from measurements or estimated using a hydrological model. Various hydrological models can be used to analyze the discharge of a river. One model that can be used is IFAS (Integrated Flood Analysis System). In this study, the IFAS model is used to estimate discharge from upper Gandul, upper Pusur, upper Soka and downstream Pusur, each with catchment areas of 29.8 km2, 10.7 km2, 22.7 km2 and 33.43 km2 respectively. The main inputs used in the model were rainfall, elevation data, land cover, watershed boundaries, and the coordinates of each watershed. IFAS model simulation results indicated that the largest of the three rivers flow upstream the river discharge was upper Gandul river which has a maximum daily discharge of 27 m3/sec while the lowest was upper Pusur river which has a maximum daily discharge of 7 m3/sec. Differences in discharge of the three rivers caused by morphometric characteristics of a watershed i.e: basin area, shape of watershed, river density, river slope, and also geological and pedological characteristics.