Enhancing Flood Protection Strategies in Algeria through the Assessment of Maximum Discharge in Wadis

Abstract For flood protection infrastructure to be designed effectively, it is essential to accurately assess the maximum discharge ( Q max ) in Algerian wadis and watercourses. In the absence of direct field measurements, reliance on foreign methodologies is common. However, these methods often overlook the specific characteristics of hydrological systems in Algeria leading to significant inconsistencies and complicating methods choice. Accordingly, the crucial question that arises is: which methodology provides the most reliable ( Q max ) estimates for the purpose of designing effective flood defenses? Therefore, this paper explores the estimation of maximum discharge in Wadis when direct flow rate data is unavailable. The proposed model, outlined in equation (3), is developed through statistical modeling and incorporates key factors such as watershed area (A) and rainfall intensity ( P tc ). The model correlates with observed discharge values by utilizing data from Algeria’s National Water Resources Agency, covering 60 Wadis across diverse regions. This approach outperforms existing models, achieving a notably low mean normalized error of 10%, signifying substantial improvements in accuracy.