Adaptation to future flooding in a lowland city - a case of Jakarta city

Abstract

Proceedings of ISERME 2020 ISERME 2020 104 Adaptation to Future Flooding in a Lowland City, - A Case of Jakarta City - *Kazama1 S, Januriyadi2 NF and Kure3 K 1Department of Civil and Environmental Engineering, Tohoku University, Japan 2Universitas Pertamina, Indonesia 3Toyama Prefectural University, Japan *Corresponding author – so.kazama.d3＠tohoku.ac.jp Abstract Hydrological model and inundation model are applied to Chilliun River Baisn including Jakarta City, capital of Indonesia to evaluate countermeasures as the adaptation in the future. For the future projection, rainfall data was made using 8 GCMs with statistic downscaling and bias correction. Future scenarios were prepared for land use change, land subsidence and 3 RCPs. Structural and non-structural countermeasures were evaluated as the adaptation for flooding. Only landuse change to 2050 increases 99% flood damage cost (almost double from current situation) and only land subsidence to 2050 increase 95% one. The combination of land use change and land subsidence makes 226% higher damage cost in 2050 than current one. This calculation shows the emphasis of both influences. Heavier downpour makes higher damage cost by flooding. Only future rainfall increases 77% and 99% on mean flood damage (annual expected damage costs) in around 2050 and 2100, respectively. However, the range of damage cost by each GCM is large and some models show the decrease of damage cost in 2050. The combination of land use, land subsidence and climate change shows 5 times damage cost to current situation.