Evaluation of Land Subsidence Prevention to Minimize the Flood Risk in a Port City

The study aims to evaluate the indirect benefit of artificial groundwater recharge in reducing the flood risk in a port city. A flood inundation model and flood damage costs model are conducted to obtain the spatial hazard map and flood damage costs. The study used three scenarios of groundwater recharge, which are indicated by the groundwater table increase. They are groundwater table increase by 0.1, 0.5, and 1.0 m. Based on the results, each scenario produces a distinct reduction in flood risk. Increasing the groundwater level by 1-m could avoid the severer future flood risk by 24.2%. In comparison, the increasing 0.1-m groundwater could decrease the future flood risk by 3.8%. Our findings could give insight to the policymakers about the importance of slowing down the land subsidence rate.