Modeling of some hydrodynamics characteristics of Orashi River in the Southern Region of Nigeria

The dynamic nature of rivers and its effect on the inhabitants and its surroundings is of fundamental concern to Hydro Scientists, Coastal Engineers, and Surveyors. These changes have remained unpredicted and hence the focus of this study. The aim of this study is to develop a geo-model of the dynamics of Orashi River in Ogba/ Egbema/ Ndoni Local Government Area of Rivers State. The objectives are to determine the river dynamics parameters, to develop a functional multiple regression model of Orashi River dynamics and to determine the percentage contributions of each of the independent variables. This study was carried out using classical survey methods such as river current measurement, river cross-sectional area determination, river water discharge rate determination, bathymetric operation, runoff water computation, water gauge reading and conventional ground surveying.  A multiple regression analysis was carried out using data obtained in 2013, 2015 and 2017 used as the independent variables while the river level changes is used as the dependent variable. The result of this study show changes in the river current and river discharge. The data analysis show the contribution of the independent variable to the dynamics of Orashi River for 2013 to be 24.83%, 30.63%, 20.24%, 0.33% and 24.97% for river current, runoff peak discharge, rainfall intensity, temperature and humidity respectively. The analysis was also carried out in 2015 & 2017and different results were obtained. A functional model of the dynamics of the changes in Orashi River was developed for 2013, 2015 and 2017 which can be used in monitoring the changes in Orashi River.