Analisis Frekuensi Aliran Tinggi pada Beberapa Daerah Aliran Sungai di Pulau Jawa

Abstract

Information about highflow frequency and its magnitude is needed for sustainable watershed management. The objectives of this research were to determine highflow threshold and to analyse highflow frequency of Ciujung, Brantas and Bengawan Solo river basin. Long term daily streamflow data were analysed using annual maximum series (AMS) and partial duration series (PDS). Exceedence frequency 5% was chosen as highflow threshold. Based on the threshold, return period of highflow from PDS and AMS was compared. Analysis result showed highflow threshold values of Bengawan Solo, Brantas and Ciujung watershed were 1,304 m3/s, 668 m3/s and 298 m3/s respectively. Log Pearson Type III was used to estimate highflow values at greater return periods. The plotting position of AMS showed smaller discharge than PDS at the same return period. While data analysis showed AMS discharge in various return period tend to be greater than PDS