The prediction of flood damage in coastal urban areas

The increase of impervious surfaces in the urban area triggers a flood. A flood occurs area with a dense population that will result in a lot of damage. The flood simulation itself is not adequate to calculate the flood damage, as it only shows the flood depth and extent. It needs the capability of mapping software to map the vulnerable area. Accordingly, the research study's aim is to propose the methodology to predict the flood damage on the coastal urban area by combining the flood simulation model with GIS mapping software. MIKE FLOOD and ArcGIS were used to represent the flood simulation model and mapping software. The flood depth and inundation area were calculated with MIKE FLOOD; meanwhile, the residential house was mapped using ArcGIS. Both of MIKE FLOOD and ArcGIS were then combined to obtain the flood depth in each residential house. Moreover, to value the flood damage in monetary terms, the depth-damage curve and average house prices were applied. The result shows that the majority of the inundation caused by riverine flood and coastal area is the place where the largest inundation area occurs. As the flood appears in a residential area, the flood damage of the residential building in terms of annual average damage (AAD) was obtained with the amount of $8,716,227.67 calculated from six AEPs (50%, 20%, 10%, 5%, 2%, and 1%).