Study of Sedimentation Rate at Irrigation Area Baluase Sigi Biromaru Regency as a Watershed Damage Identification

Abstract

The high sediment contained in the canals causes changes in the dimensions of the canals. It can reduce the cross-sectional capacity of the canals. The Baluase Irrigation Area is located in Sigi Regency, Central Sulawesi Province, with a functional area of 94 Ha. This study aims to determine the rate of sedimentation in the Baluase Irrigation Secondary canals, which is expressed in the correlation coefficient (R), which is the relationship between Sediment Discharge (Qs) and Water Discharge (Qw). Primary data were collected by direct measurements at the location by measuring canals dimensions, water level, velocity and water samples to test sediment concentration. Sediment samples were taken at 2 distances of flow depth, namely 0.2 h and 0.8 h with 8 cross sections in the longitudinal direction of the canal. From the research results, the average sedimentation rate in the Ramba secondary canal is 3,574 kg/day, while the Baluase secondary canal is 5,675 kg/day. The correlation coefficient (R) value at 0.2 h was 0.6994 and 0.8229 for a depth of 0.8 h. This shows that the relationship between sediment discharge (Qs) and water discharge (Qw) has a positive relationship between 0.6 < R < 1.0