Design and construction of a flood-warning system prototype based on embedded systems for river Nyamwamba, Kasese district.

Abstract

This Final Year Project report contains all the details of a study on the design and construction of a Flood Warning System (FWS) for River Nyamwamba of Kasese district – a river that has been prone to floods of a greater magnitude than other rivers in the Tropical region of Africa. The idea was developed on a principle that floods are a meteorological event that develops over time, and thus a need for sufficient time for people to evacuate, and to protect their lives and property. However, the range of existing FWSs have a tangle of conflicting requirements in terms of cost and reliability, and have challenges from factors as diverse as technological and social. The complexity of these systems and need for autonomy while remaining maintainable and accessible by nontechnical personnel is a bottle-neck that is often unsolved in developing countries. Built on Computer Embedded Systems, this study is about a cheaper and reliable FWS for a country like Uganda. The study began with modelling the flow of River Nyamwamba with different datasets (i.e. DEM, Topography sheets, river map, imageries, flow data, stage data, land use maps and rainfall data) that were collected from field work and various offices. The datasets were conditioned and processed in a GIS environment using the ArcGIS software. The result was further exported to the HEC-RAS program to perform a steady flow simulation of the river. The RAS mapper export from HEC-RAS was then re-imported back into ArcMap to delineate a flood plain that was overlaid to a Google Earth image to visualize and determine the high risk areas along the river. The high risk areas provided reliable river flow parameters that were used as input values for the design of the FWS. The FWS was built on a technology of Computer Embedded Systems that employs Arduino programmed microcontrollers to control all input and output values regarding the modelled river. An ultrasonic sensor was used to monitor water levels at three threshold points (i.e. Level 1 for normal flow, Level 2 for an intermediate flow, and Level 3 for a peak flood level). From this, the river stage was displayed onto an LCD screen at all times, an electronic SMS was sent to operators at intermediate flow, while an Alarm was sounded at Flood level.

Key Words: Geographical Information Systems, Flood Frequency Analysis, Flood Mapping, Modelling, Flood Warning Systems, Embedded Systems, Simulation, Design, and Construction.