The 24th IAHR-APD Congress (24th IAHR-APD Congress)

395 / 2024-03-11 22:05:32

Assessing the benefits of Nature-based Solutions with in-situ flood detention in Taiwan by hydraulic simulation

NbS, in-situ flood detention, farmland, Climate change, SOBEK

Subtheme 1: Water-related Hazard and Risk Reduction > Topic 3: Smart Management of Water Hazard and Risk

Due to continuous global warming, rainfall patterns have changed. In order to mitigate the impact of climate change, natural-based solutions are gradually being developed internationally. For reducing the risk of extreme rainfall, the Taiwan government has put forward the idea of in-situ flood detention, using raised ridges or the height of roads next to farmland, creating detention ponds as a temporary storage space for intensive rainwater. Compared to previously built traditional detention ponds not far away, this measure reduces engineering work and maintains the productivity of agricultural land. Naturally speaking, the farmland can bear and absorb floodwater. In this study, Youcai Village, Baozhong Township, Yunlin County, an in-situ flood detention demonstration area, was used as a research area. We chose the rainfall change rate of the IPCC Fifth Assessment Report (AR5) RCP4.5 published by the Taiwan Climate Change Projection Information and Adaptation Knowledge Platform (TCCIP) to estimate the potential rainfall in each recurrence interval in the study area in the middle of the century (2036~2065). SOBEK software was employed for flooding simulation, and the effectiveness and sustainability of in-situ flood detention in this century were discussed based on the results.