235 / 2024-02-28 14:09:40

Numerical study on the coastal flood in Minjiang Estuary, China

coastal inundation,Minjiang Estuary,climate change,sea level rise,multi-tracks

Coastal flood, especially that induced by Tropical Cyclones (TCs), can induce severe damages, losses and even mass casualties, and are expected to be exacerbated by sea level rise and TC climatology changes in the warmer future. In this study, we establish a high-resolution numerical model covering all low-lying land in the Minjiang Estuary, Fujian, China based on FVCOM. This model is then used to assess the coastal flood in the Minjiang Estuary under TCs with pressures of return periods of 10, 100, and 1000 years. A multi-tracks blend method is applied to ensure each area are adequately impact by the TCs. Two scenarios of current climate and warmer future climate (by 2100 under SSP5-8.5) are simulated. Results show that the flood area and flood durations increase significantly with the increase of TC intensity. Flood disaster can be strongly exacerbated by climate change and sea level rise. And most of the exacerbation can be attribute to sea level rise. Flood areas under TCs with 100-years pressure in 2100 are estimated to be nearly equivalent to that under TCs with 1000-years pressure at current climate. The most increased exposure area by climate change are artificial surfaces and agricultural areas, showing the potential higher flood disasters in future. Nevertheless, the persistent coastal migration will increase population and properties in the coastal low-lying land, which results in more exposure, and further exacerbate the flood risk in the Minjiang Estuary.