Engineering challenges in flash flood mitigation: insights from historical data and community perceptions in Tamanghasset, Algeria

Flash flooding poses escalating risks for arid communities despite low rainfall. This study analyzes the complex flood history of the desert oasis town of Tamanghasset, Southern Algeria, to uncover key patterns. Archived flood records from 1976 to 2018 are visually examined for timing, location, losses, and rainfall correlations. Questionnaires gather localized risk perceptions from residents. Results reveal distinct summer flood seasonality, with August highest. Tamanghasset city and In Guezzam emerge as hotspots, while rural valleys show greater fatalities. Flood frequency increased after 2000, with 2010 an extreme outlier. Heavy rainfall corresponded to major events. Overall, findings detect intensifying hazards, though variability persists. Spatial, temporal, and social vulnerability characterization from records and questionnaires informs adaptation needs. Enhanced infrastructure, forecasting, and preparedness are essential to reduce rising impacts. Further work could expand statistical analysis given more data. This assessment delineates Tamanghasset's escalating yet fluctuating flood hazard profile, providing crucial insights for disaster risk reduction strategies in arid regions facing similar challenges. The study's mixed-method approach, combining historical data analysis with community perceptions, offers a comprehensive understanding of flood risk dynamics in this unique desert environment.