A recent study published in the Journal of Hydrology: Regional Studies offers insights into the best locations for dams to prevent flash floods and minimize loss of life. The collapse of two dams in Libya last month, triggered by the aftermath of Storm Daniel, led to widespread destruction, loss of livelihoods, and thousands of fatalities, pushing Libya into a state of extreme emergency.
The research, conducted by Dr. Ashraf Ahmed, a flood expert and chartered engineer from Brunel University London, in collaboration with researchers from Benha University and Zagazig University in Egypt, is shedding light on essential considerations for dam designers and decision-makers when selecting dam sites and constructing them.
Dr. Ahmed's study centered on Wadi Tayyiba in South Sinai, Egypt, an area prone to flooding the nearby city of Abou Zenima due to excessive surface runoff. The floods in this region have resulted in significant losses in terms of lives, property, and infrastructure, with a substantial portion of floodwater going to waste.
To address these challenges, Dr. Ahmed emphasized the importance of developing dams with sub-basins, areas that channel rainfall runoff to storage reservoirs or lakes. His research incorporated rainfall data, soil type assessments, and computer simulations to model the rainfall-runoff relationship in Wadi Tayyibah over a 100-year period. The outcome was a comprehensive flood hazard map for the area and the identification of cost-effective dam locations.
Dr. Ahmed underscored the significance of assessing the geological composition of basins and the presence of slopes, as increased slopes can intensify water outflows and flood risks. Moreover, he emphasized the need to evaluate the impact of highways that traverse an area, as these roads are susceptible to surface runoff.
The study recommended the construction of eight dams in Wadi Tayyibah, dividing the area into four sub-basins alongside a storage lake. The research highlighted the importance of choosing dam locations that align with the natural landscape, emphasizing the need for dams to be situated between two high points and near a suitable lake or reservoir with adequate storage capacity.
Dr. Ahmed believes that his findings offer valuable insights for decision-makers worldwide, aiding them in selecting optimal locations for storage dams. Beyond mitigating flash floods and safeguarding lives, the study underscores the economic benefits of strategically placed dams, which can store water for future use.
In the future, Dr. Ahmed envisions the integration of artificial intelligence techniques to forecast dam locations for rainfall harvesting and flash flood mitigation, further advancing the field of dam construction and management.
The study, titled "Identifying cost-effective locations of storage dams for rainfall harvesting and flash flood mitigation in arid and semi-arid regions," authored by Amir S. Ibrahim, Ashraf Ahmed, Islam S. Al Zayed, and Ismail Abd-Elaty, is published in the Journal of Hydrology: Regional Studies.
