Agricultural drainage pipe in Guadua angustifolia: implications of Manning roughness in Pitalito forest stands

Abstract

Water extraction in agricultural fields with high saturation levels requires drainage systems that increase land preparation costs, so looking for new options for materials that function as drainage pipes that provide a better technical–economic relationship is crucial. In this study, Manning roughness values were analyzed in the culms of Guadua angustifolia considering three factors: flow, section, and location site of the forest stands. This study was carried out in the rural area of the municipality of Pitalito; the characterization of culms was made based on the Colombian technical standards (NTC) 5726 and 5727, the cutting and elaboration of test pieces according to the NTC 5525, and finally, the hydraulic tests were carried out. The roughness values oscillated between 0.1089 and 0.0337 according to the different flow evaluated values in the laboratory tests, between 0.1004 and 0.0356 for the sections analyzed, and between 0.0909 and 0.0533 according to the sample extraction area. The multifactor ANOVA established a significant relationship for the flow and section on the Manning n roughness, while the zone was insignificant.