Modelling the occurrence of floods on Muyembe river and testing an appropriate structure to mitigate.

Abstract

This project research is about Modeling the occurrence of floods on river Muyembe and testing an appropriate structure to mitigate for River Muyembe in Bulambuli district. This work is presented in chapter form. Chapter one is composed of the introduction to the research problem. Chapter two contains a review of literature which has been produced by other scholars and researchers about flood modelling. The third chapter presents the various methods which were employed to achieve the objectives amongst them were; to develop the hydraulic model of river Muyembe which was done by HEC-RAS software. The fourth chapter presents the findings from the research. The communities living along Muyembe River found in Bulambuli district experience frequent floods threatening their lives and property. Climate change and anthropogenic perturbations to the natural environment increase flooding frequency. Recently, the development of models for flood calculation and hazard assessments has made full use of the advancement in computer-aided technology. This study focuses on applying a hydraulic model (HEC-RAS) in a GIS context for the flooded areas of Muyembe sub county in Bulambuli district, and produces inundation maps, flood depth, and water surface elevation of 15, 25, 50,100, 500, 1000-year Return Period. The research included reading a variety of literary works and gathering supplemental information in the form of journals and reports. This aided in developing the project's technique as a whole. The stage of modeling came next. The initial data collection process used a number of sources, including DEM, discharge flow, rainfall, and soil data were all collected. These datasets were prepared and processed in the GIS environment using the ArcGIS application. The HEC-RAS program was used to compute for unsteady flow simulation and create geometry data. The area's flood extent was viewed using the RAS Mapper. Two major hydraulic structures were considered in this research i.e. a weir and a dam to determine the most appropriate for flood mitigation of floods along river Muyembe. Various return periods were run in absence of any structure and then also ran with the presence of a weir and a dam while observing a significant drop in the depth downstream.