Study of the Flood Flow of the Zagaro River using Numerical Methods

Abstract

River floods pose a significant risk when they occur, as they threaten areas adjacent to waterways and cause damage to public and private property, both urban and economic, as well as social, and kill thousands of people around the world.

Flood control was necessary through the construction of dams and water facilities to protect against flooding, despite their high cost without adequate information gathering and careful study of the flow and the factors affecting it. Therefore, it is necessary to understand the behavior of the flow and study its movement during flooding to identify its risks and work to mitigate them.

This research presents a study of the flood flow movement in the Zagaro River by developing a mathematical model using numerical methods based on the Geographic Information Systems (GIS) program and the Hec-Ras program. Through modeling using Hec-Ras, water levels and flow velocity are determined at different cross-sections along the river. The study determined the flood inundation map for the Zagaro River for a flood wave with a probability of 1%. The total discharge value reached 431.9 m³/sec during a concentration time of 2.7 hours. The water height values ​​in the channel ranged between 0.6 m and 6 m. The flood map showed the formation of the flood and help in identifying the areas of flood spread and identifying the areas of damage in order to provide the necessary means of protection to reduce the expected risks resulting from the flood, both human and economic.