MODELLING OF SEDIMENTS CONCENTRATION DISTRIBUTION IN DREDGED CANALS OF THE NIGER DELTA ESTUARINE REGION, NIGERIA

Abstract

Previous sediments concentration distribution models used in the study of sediment characteristics of the dredged canals in the Niger-Delta estuarine region, Nigeria; did not take into consideration the lateral inflow due to tidal effects, which affects tremendously, the sediment intake into the estuarine waters. In the current research, existing models are modified by incorporating the missing lateral inflow parameters, which are peculiar to the Niger Delta environment, to obtain more accurate model results. Details are given herein, of the development and application of a 3-dimensional numerical model (EKU 2.8 Models) to predict sediment concentration distribution (total suspended sediment & bed sediment loads) in the Niger Delta estuarine canals, with Ekulama well 19 access canal as a case study. The approach in this paper involved coupling a sediment transport equation (with the inclusion of lateral inflow parameters), with an estuarine hydro-dynamics equation to generate a generic 3-dimensional sediment concentration distribution model, using deterministic approach. Predicted results using this model compared favorably with measured field results. Average sediment concentration of 29mg/l was obtained compared with 31mg/l measured in the field for bed sediment loads. Finally, the predicted sediment concentration distribution (TSS), when compared with field results, gave average correlation coefficient of 0.9.; hence, the present model will assist in generating adequate information /data on sediment characteristics and transport mechanism, required for effective design of canals to reduce rate of siltation. The application of the above knowledge/parameters generated from this model to effectively design canals to reduce siltation will be treated in subsequent articles.