EVALUASI PENGGUNAAN LENGKUNG LAJU DEBIT-SEDIMEN (SEDIMENT-DISCHARGE RATING CURVE) UNTUK MEMPREDIKSI SEDIMEN LAYANG

Abstract

ABSTRACT Sediment-discharge rating curve is well known method in predicting suspended sediment discharge. The correlation is usually developed as a relationship between suspended sediment load and discharge. Ideally, the measured of discharge and sediment concentration are carried out continuously, as suspended sediment load is more depended on the sources, i.e. the erosion rate on the catchment rather than the river hydraulic. In practice, the discharge and sediment concentration are carried out intermittently or in spot, as it is time and cost consuming. Therefore, the use of sediment-discharge rating curve to predict suspended sediment may generate an error. This study is stressed to evaluate the accuracy of sediment-discharge rating curve in predicting suspended sediment. The estimated sediment was compared to measured reservoir sedimenation. Sediment was estimated based on various sediment-discharge rating curves. The result showed that the present sediment-discharge rating curve (year 2002) produced a higher sediment reservoir estimation than that was measured. By using continue daily discharge the error was less than using the daily discharge from average three point measurement. The different varies from 13.53 % to 24.44%.