Development of an Empirical Hydrologic Model to Determine Manning and Runoff Coefficient for Some Selected Soils of the Permanent Site of Federal University of Technology, Minna, Nigeria

Abstract

The determination of the volume and rate of movement of surface water within a watershed are the fundamental steps upon which the design of reservoirs, channel improvement, erosion control structures and servers as well as agricultural, highway and various drainage systems are based. The concept of integrated watershed runoff coefficient has emerged as a new understanding for the interactions between the surface and subsurface pathways of water. A runoff plot was set up to measure surface runoff for the type of soil under controlled conditions. The plot was established directly in the project area with a slope of 9% and length of 22.9 m. Several runs of the experiment were conducted on the plot to help determine the type of parameters (amount of surface runoff, time of concentration, slope, and rainfall intensity) that will be considered for the development of the model. The model developed for this study is . This was compared with already existing models and it proved to be a better model to determine Manning-Nigeria coefficient.