Assessment of Flood Damage to Residential Houses and Analysis of Effectiveness of Flood Damage Reduction Measures

Abstract

Developing a quantitative flood damage estimation method is important to plan and implement effective adaptation and preventive measures for reducing flood damage to residential areas. We thus developed a flood damage assessment method by integrating hydrologic-hydraulic simulation model outputs and a flood damage model capable of considering house characteristics, and conducted the quantitative assessment of flood damage to houses and household contents, including the effectiveness analysis of flood damage reduction by the use of existing dams for flood control and elevating the plinth level of houses. We also developed average flood damage curves as a function of flood depth for the houses considering house types and also for household contents, using secondary data sources. Selecting the Solo River basin of Indonesia as the study area, we computed flood characteristics using a water and energy budget-based rainfall-runoffinundation model and estimated flood damage using the developed flood damage curves based on house characteristics and the exposed property value. The findings show that the use of the dam for flood control in the basin can reduce the expected annual damage (i.e., the average total expected damage per year from all flood probabilities) to residential areas by 21%. Flood damage to households can be reduced by more than 45% by elevating the plinth level height.