Quantitative Flood Risk Projection in Java Island, Indonesia

Quantitative risk assessment is useful to determine the actual risk conditions from the society. This paper aims to assess quantitative risks due to flood disasters in Java Island and project the risk until 2030 based on land change scenarios. Quantitative risk is assessed by integrating hazard, vulnerabilitiy, and elements at risk through Geographic Information Systems (GIS). Flood hazard is represented by inundation depth. Vulnerability is represented by a vulnerability curve for relating flood depth with the probability of damage level. While the elements at risk consists of house and population. Risk projection is carried out based on land change scenarios. This scenario is modeled using the relationship of the availability of foodstuffs energy to the population. The results show that during 2014 - 2030, the number of populations and houses that affected by floods has increased around 13.99% and 31.84%. The estimated economic losses from house building about Rp1.797.258 billion in 2014 and increase up to Rp3.240.681 billion in 2030.