SIMULASI TRANSPOR SEDIMEN SUNGAI PROGO DI SEKITAR INTAKE KAMIJORO

Abstract

Kamijoro Intake is one of the irrigation structure in Progo River to supply irrigation area in four subdistricts in Bantul Regency. In its development, Kamijoro Intake can not operate optimally because of the sediment deposition around the intake. It encourages research to find out flow pattern and sedimentation pattern of the Progo River especially around the segment of Kamijoro Intake. Two dimensional mathematical simulation of flow pattern and sedimentation pattern was conducted by using I-RIC software especially Nays2DH module. The simulation was conducted with two types of discharge, they were wet month discharge and dry month discharge. The simulation results showed the greater discharge could yield greater the parameter values of flow pattern such as depth, velocity, and Froude number in the river flow. The discharge also affected the Progo River flow around Intake Kamijoro such as deformation river bed, suspended load concentration and bed load flux. These parameters in wet month discharge was greater than dry month discharge. The largest suspended load concentration and bedload flux were found in cross 2 (in Intake Kamijoro), while the suspended load concentration values was 0,866 x 10-5 mg/l and the bedload flux was 0,00076 m2/s. Higher sediment deposition around Kamijoro Intake found in upstream and downstream of intake areas caused sedimentation that could interfere the operation of Kamijoro Intake.