Department of Environment and Soil Sciences, University of Lleida, Alcalde Rovira Roure 191, E-25198 Lleida, Catalonia, Spain.
Integr Environ Assess Manag. 2011 Apr;7(2):256-68. doi: 10.1002/ieam.126. Epub 2010 Aug 3.
Sediment flows naturally through the drainage network, from source areas to deposition zones. Sedimentary disequilibrium in rivers and coastlines is related to the imbalance within the fluvial system caused mostly by dams, instream mining, and changes in land use. This phenomenon is also responsible for ecological perturbations in rivers and streams. A broad need exists to establish comprehensive management strategies (soft measures) that would go beyond site-specific engineering practices (technical measures) typically taken to solve particular problems. Long-term programs are also required to monitor sediment transport in river basins, in order to assess the magnitude and variability of sediment transfer and potential deficits. This paper shows examples of rivers with important sediment disequilibrium in the Ebro and adjacent basins. These basins, like most in the Iberian Peninsula, experience sediment discontinuity in the catchment-river-coast system. Reservoir siltation is the main quantitative issue. Land use change and especially gravel mining downstream from dams accentuate the process. We also present and discuss recent developments on water and sediment management undertaken to improve the morphosedimentary dynamics of rivers.
泥沙自然地通过水系从源区流到沉积区。河流和海岸线的沉积不平衡与河流系统内的失衡有关，这种失衡主要是由大坝、河流内采矿和土地利用变化引起的。这种现象也会导致河流和溪流的生态干扰。广泛需要建立全面的管理策略（软措施），这些策略将超越通常用于解决特定问题的特定地点的工程实践（技术措施）。还需要长期方案来监测流域中的泥沙输移，以评估泥沙转移的幅度和可变性以及潜在的亏缺。本文展示了埃布罗河和邻近流域中重要的泥沙不平衡的河流实例。这些流域与伊比利亚半岛的大多数流域一样，在集水区-河流-海岸系统中经历泥沙不连续性。水库淤积是主要的定量问题。土地利用变化，特别是大坝下游的砾石开采，加剧了这一过程。我们还介绍和讨论了为改善河流形态沉积动力学而采取的水沙管理的最新进展。
