Flooding in arid regions presents a complex challenge, as it is not simply a temporary occurrence, but a test of how well both the natural and urban environments can absorb floodwaters and reduce their impacts. It also serves as a critical test of human planning capabilities. In this context, the present study, conducted by a research team led by Dr. Ghazi bin Ali Al Rawas, from the College of Engineering, examined Wadi Al Sarami in North Al Batinah as a case study for understanding flash floods, not solely as a hydrological phenomenon, but as an issue intrinsically linked to geography, urbanisation, and public administration. 

The significance of this research lies in its holistic treatment of the wadi and the urban environment as a single interconnected system. Water accumulating in mountainous headwaters does not remain confined to natural catchments; rather, it continues its downstream flow until it reaches urban areas where risks to populations and infrastructure intensify. The study highlights that the North Al Batinah coastal plain, characterised by its flat topography and rapid urban expansion, has been repeatedly exposed to severe flooding events in recent years, making the pursuit of more comprehensive mitigation approaches an urgent necessity. 

The researchers employed the Storm Water Management Model (SWMM) to simulate hydrological and hydraulic behaviour across both upstream and downstream zones. Effective flood management in catchments comprising non-urban upstream areas and urban downstream areas requires integrated solutions rather than fragmented, sector-specific interventions. Accordingly, a multi-layered approach was developed, beginning with the optimisation of retention dam locations and dimensions in the non-urban section using a multi-objective optimisation framework. This was followed by scenario selection through the COPRAS (Complex Proportional Assessment) method, and the application of game theory (BIGT) to resolve conflicts of interest among concerned authorities. The approach then extended to the redesign of the urban drainage network.  

The study did not stop at the engineering solution alone; it also applied Backward Induction in Game Theory (BIGT), a method used to analyse decision-making interactions among concerned authorities. This approach aims to select a solution that balances flood management between the upstream and downstream areas while reducing conflicts of interest between them. It also seeks to align the priorities of the relevant parties, primarily the Ministry of Agriculture, Fisheries and Water Resources and the Municipality of Sohar. The methodology involves improving flood control in the upper catchment area, then designing the urban drainage network based on these upstream conditions, and finally selecting the most balanced and suitable solution for all parties involved. 

The results indicate that, compared with the baseline scenario, the selected plan reduced peak discharge at urban entry points by 60.7%. It also increased the drainage network’s flood absorption capacity to 81.8%, a metric reflecting the system’s ability to accommodate flood volumes and mitigate their impact. This indicator measures performance relative to both worst-case and best-case design scenarios (Vmax and Vmin). The proposed plan included 11 retention dams strategically distributed across key locations within the catchment, with the largest structure (D3) reaching a height of 10.9 metres. This demonstrates that the solution was not based on a single rigid intervention, but rather on an adaptive design responsive to the valley’s topography and flow characteristics. 

The study concludes that flood management cannot be effective when either the upstream or downstream components are treated in isolation. Instead, the entire catchment area must be understood as a unified system that integrates modelling precision, infrastructural efficiency, and institutional coordination. In doing so, flood management shifts from a reactive response to a more anticipatory, balanced, and enduring form of intervention. 

https://www.sciencedirect.com/science/article/pii/S0048969724079191