Sediment Transport Constraints for Restoration of the Ebro Delta

The natural flow of sediment in the Ebro River has been altered by a variety of factors that have impacted the geomorphic and ecological balance of the delta. Ongoing restoration efforts in the delta would benefit if the flow of sediment in the river could be increased. Understanding the dynamics of sediment flow in the Ebro River is an important component in the design of effective management strategies for the Ebro Delta. This study estimates the sediment transport potential of the Ebro River under current and future conditions through numerical simulation. Historical data from the late 19th century indicate that the river once transported up to 28.1 million tons of sediment per year. However, due to water abstractions and flow regulations, the current sediment transport capacity is limited to 9 million tons annually, a reduction of 67%. Future projections suggest further decreases in flow and sediment transport potential, with reductions of up to 30% by 2060 and 50% by 2100, depending on climate conditions and water management practices. The findings underscore the need for integrated management strategies to mitigate the impacts of reduced sediment flow, emphasizing the importance of restoring sediment transport as a crucial component of the delta restoration efforts.