Analysis of the impact of flood disasters on aquaculture in a warming scenario – with aquaculture in Pingtung County as an example

ABSTRACT To understand the impact of flood disasters on aquaculture in a warming scenario, this study used typhoon event data generated by the Taiwan Climate Change Projection Information and Adaptation Knowledge Platform (TCCIP) under the AR5 RCP8.5 scenario, including 149 events in 1979–2008 (Hist) and 450 events in 2040–2065 (Mid21). The SOBEK model was applied to simulate and analyze flood disasters in the watershed of Pingtung County (including 21 catchments) under climate change scenarios. The SOBEK model includes rainfall-runoff, channel-flow, and overland-flow modules. The analysis results indicate that areas with flood depths exceeding 30 cm were primarily concentrated in the Donggang, Linbian, and Peishih River basins. The flooded area within these three river basins accounted for approximately 58.8% of the total simulated inundated area during the historical period (Hist) and about 61.4% during the mid-21st century scenario (Mid21), averaging roughly 60%. Considering the spatial distribution of fish farms, the simulation results indicate that in Hist, approximately 4.75 km2 of fish farms were affected by flooding depths above 30 cm, while in Mid21, the affected area is projected to increase to about 19.21 km2, representing roughly a fourfold expansion. Therefore, relevant adaptation planning is particularly critical to mitigate future risks.