Hydraulic Modeling to Improve Urban Flood Hazard Maps on Catumbela

1. Civil Engineering Department, Hydraulics, Water Resource, and Environment Division, Faculty of Engineering, 

University of Porto, Portugal

2. Group of Hydrology and Water Resources, Faculty of Engineering, Agostinho Neto University, Angola

Abstract: This research aims to simulate flood hazards in vulnerable areas of Lobito (inhabited area in the Catumbela Basin G1) like populated floodplains G1, G2, and G3 by means of hydraulic modeling software that is a crucial aspect of any flood mitigation efforts. In this framework, the hydraulic models were generated based on a Digital Elevation Model (DEM) and processed within Geographical Information Systems (GIS), therefore, enabling the production of flood inundation maps. This research developed a flood vulnerability assessment for streamflow within the Catumbela floodplain, based on 1D HEC-RAS hydraulic modeling and LiDAR derivate DEM with 1 m spatial resolution. These results were compared with the most recent flood event records that were proved by local people. It was revealed that the 1D HEC-RAS provides a more realistic perspective about the possible flood risk and can help with floods reduction efforts ongoing, such as material damage and death toll caused by the Catumbela floods.