DETERMINATION OF THE ROUGHNESS COEFFICIENTS OF PERIWINKLE AND PALM KERNEL SHELL ON A CLAY LOAM SOIL IN AROCHUKWU, SOUTH-EASTERN NIGERIA

Abstract

Roughness coefficient is one of the parameters applied during earl h constructions. Its efficiency is evident  on constructions of water channels and roads if appropriately chosen. In this work, roughness coefficient of periwinkle and palm kernel shells were determined on a soil predominantly clay loam with hilly topography of slope values of 18.5 - 30%. The study was also carried out on twin plots of 10.2m long, 3.5m width, and 0.3m deep laid with periwinkle and palm kernel shell surface forms each. After the overland flow had been established through simulation, hydraulic characteristics of flow such as hydraulic depths and velocities of flow were measured at six different points across each twin plot and in all the locations, These were fined into the Darcy- Weisbach roughness coefficient model Io determine the roughness coefficient values for periwinkle and palm kernel shells. Reynolds number of flow on both surfaces were equally estimated by using the measured flow velocities, hydraulic depths and the kinematics velocity data at different sections of the Twin plots in all the locations. The periwinkle shell surface forms produced higher roughness coefficient of 27.134, 26.985,29.778, 47.11, 38.311 and 47.334 than that of palm kernel shell surface forms with roughness coefficient of 15.64, 23.11, 9 .310, 13.614, 19.61 and 11.90