Rainfall Runoff Model for Calabar Metropolis Using Multiple Regression

Mathematical analyses were used to develop model that predicts the influence of some hydraulic and hydrologic parameters on the perennial flooding of some parts of the Calabar Metropolis. The parameters were obtained from ten sampling locations all within Calabar metropolis. An empirical model was developed to predict discharge based on the independent variables of cross sectional area of drains, degree imperviousness, gradient, sum of channel length, and basin area. The model developed gave a good multiple regression coefficient of 0.982with a standard error of 0.709at a significance level of 0.10. The R2 value of the regression model shows that 96.4% of the total variation in the storm water discharge is accounted for by the five regressors. Incorrect sizing and spread of drains as well as the existing slopes employed in the generation of the drainsb invert during construction have been seen as some of the key factors that foster flooding in the Metropolis. Designers are encouraged to employ the model developed for drains design and analysis for Calabar Metropolis.http://dx.doi.org/10.4314/njt.v33i4.1