Wadi flood impact assessment of the 2002 cyclonic storm in Dhofar, Oman under present and future sea level conditions

Oman witnessed exposure to various cyclones during the last decade including Gonu (2007), Phet (2010), Keila (2015; Dhofar), and Mekunu (2018; Dhofar). The purpose of this study is to assess flood damage due to flash wadi (dry river bed) flooding in Dhofar under present and future sea level conditions. This study uses a 3Di hydrodynamic model and a damage model to quantify the flood extent and flood damage due to the 2002 cyclonic storm (ARB01) and to identify vulnerable infrastructure in two watersheds: Zayk and Ghadow. The impact of the storm is assessed under present day and predicted 1.41 m sea level rise (SLR) conditions. The results show that with present sea level conditions the residential damage was estimated at US$ 10.79M and US$ 32.98M for Zayk and Ghadow respectively. Under a 1.41 m SLR scenario, the residential damage is projected to increase to US$ 13.65M (26.5%) and US$ 40.28M (22.1%) for Zayk and Ghadow respectively under a similar cyclonic storm event. These results provide knowledge to make informed policy decisions that contribute to the development of resilient infrastructure. It also provides a flood damage assessment of a potential future to prepare Oman for challenges under sea level rise.