Spatial-temporal vulnerability and risk assessment model for urban flood scenario

As urban areas grow both geographically and demographically, the flood hazard and risk has been increased in the sub-districts of Makassar region recently. Hence, planning the urban areas will require a spatial analysis of flood risk assessment scenario to ensure that the potential developments arising from urbanization are optimized to reduce damages by floods. This paper presents a spatial and temporal model analysis for flood vulnerability and risk assessment, with the aim to establish a risk index at sub-district scales for urban flood scenario in the Makassar region. Firstly, we develop the overall vulnerability assessment to floods based on the local framework analysis of the BNPB (The Indonesian National Board for Disaster Management) and the use of Geographic Information System (GIS) modeling approach. Using a GIS grid mesh model of 50 meter scales as the spatial treatment unit spatial-temporal analysis, the study aggregated the local indicators to a single composite index that enable spatial vulnerability representation at sub-district levels. These indicators were composed from various social, physical, economic, and environmental factors. Secondly, GIS analysis conducts grid index modeling of flood hazard model by incorporating the measurement of floods in 2013, as a flood hazard scenario. Finally, by combining the spatial factors of flood hazard and flood vulnerabilities, a spatial and temporal risk assessment model has been simulated at sub-district scales to evaluate the potential impact to the social, physical, economic, and environmental aspects.