J. Amorocho Hydraulics Laboratory, Department of Civil and Environmental Engineering, University of California, Davis, CA 95616, United States.
Dept. of Water Resources, Division of Flood Management, State of California, 3310 El Camino Ave., Sacramento, CA 95821, United States.
Sci Total Environ. 2017 Dec 31;607-608:613-622. doi: 10.1016/j.scitotenv.2017.06.271. Epub 2017 Jul 27.
Extreme floods are regarded as one of the most catastrophic natural hazards and can result in significant morphological changes induced by pronounced sediment erosion and deposition processes over the landscape. However, the effects of extreme floods of different return intervals on the floodplain and river channel morphological evolution with the associated sediment transport processes are not well explored. Furthermore, different basin management action plans, such as engineering structure modifications, may also greatly affect the flood inundation, sediment transport, solute transport and morphological processes within extreme flood events. In this study, a coupled two-dimensional hydrodynamic, sediment transport and morphological model is applied to evaluate the impact of different river and basin management strategies on the flood inundation, sediment transport dynamics and morphological changes within extreme flood events of different magnitudes. The 10-year, 50-year, 100-year and 200-year floods are evaluated for the Lower Cache Creek system in California under existing condition and a potential future modification scenario. Modeling results showed that select locations of flood inundation within the study area tend to experience larger inundation depth and more sediment is likely to be trapped in the study area under potential modification scenario. The proposed two dimensional flow and sediment transport modeling approach implemented with a variety of inflow conditions can provide guidance to decision-makers when considering implementation of potential modification plans, especially as they relate to competing management strategies of large water bodies, such as the modeling area in this study.
极端洪水被认为是最具灾难性的自然灾害之一，可能导致景观上显著的侵蚀和沉积过程引起的重大形态变化。然而，不同重现期极端洪水对泛滥平原和河道形态演变及其相关泥沙输移过程的影响尚未得到充分探索。此外，不同的流域管理行动计划，如工程结构修改，也可能极大地影响极端洪水事件中的洪水泛滥、泥沙输移、溶质输移和形态过程。在本研究中，应用了一个二维水动力、泥沙输移和形态模型，以评估不同河流和流域管理策略对加利福尼亚州下 Cache Creek 系统不同规模极端洪水事件中的洪水泛滥、泥沙输移动态和形态变化的影响。在现有条件和潜在未来修改方案下，评估了加利福尼亚州下 Cache Creek 系统的 10 年、50 年、100 年和 200 年洪水。模拟结果表明，在研究区域内的一些洪水淹没位置，洪水淹没深度更大，在潜在修改方案下，更多的泥沙可能会被困在研究区域。所提出的二维水流和泥沙输移模型方法，结合各种流入条件，可以为决策者在考虑实施潜在修改计划时提供指导，特别是在涉及大型水体的竞争管理策略时，如本研究中的建模区域。
