Kajian Nilai Koefisien Kekasaran Saluran Tersier Dengan Metode Manning dan Metode Chezy pada Jaringan Irigasi Namu Sira-Sira Desa Namu Ukur Selatan Kabupaten Langkat

Abstract

The tertiary irrigation channel in the Namu Ukur Selatan Village are is partly a soil channel and a concrete channel. The efficiency of water distribution will be influenced by the speed of water flow and channel condition, where both of these factors can be manifested through the throhness value or the channel constant value. This study ains to determine the value of Manning’s roughness and Chezy’s constant in 6 vegetated tertiary channel. In the three concrete channels, the Manning’s values are 0,22; 0,20; 0,21 and Chezy’s constant are 3,23; 3,54;and 3,56 and for the soil channel for conditions before the vegetation was trimmed, the Manning’s value were respectively 0,61; 0,53 and 0,51 and Chezy’s constant are 1,18; 1,36 and 1,4. Meanwhile in the three channels for condition afrer trimming the vegetation, the Manning’s values is 0,54; 0,47 and 0,45 and Chezy’s constant were 1,32; 1,54 and 1,6.