Development of generalized loss functions for rapid estimation of flood damages: a case study in Kelani River basin, Sri Lanka
by Akinola Adesuji komolafe, Srikantha Herath and Ram Avtar
The study emphasizes the importance of assessing infrastructural vulnerability to natural hazards and quantifying economic losses to enhance disaster risk reduction efforts. It aims to develop flood-vulnerability models for different types of structural buildings, focusing on the Kelani River basin in Sri Lanka.
An empirical approach is adopted, utilizing data collected through survey questionnaires to directly estimate flood damages in flood-prone areas of the basin. The survey questionnaires help establish depth-damage functions for four identified structural building types, establishing the relationship between inundation depths and the resulting flood damage ratio.
To simulate event-based flood hazards, the Flo-2D model is employed. Remote sensing data is utilized to derive building exposures and densities through integrated thematic land cover feature indices and supervised image classification.
A modified mathematical loss model is then utilized to simulate flood damages for each building category during a catastrophic flood event in the Kelani River basin. The simulated damages are compared with post-flood survey data to ensure the reasonableness of the models. These models can be effectively used for estimating future damages and formulating risk-reduction plans to mitigate flood disasters in Sri Lanka.
Overall, the study highlights the significance of developing vulnerability models and utilizing empirical data to quantify the potential damages caused by floods. This information can aid in formulating effective strategies for risk reduction and disaster management in the region.
