Resilience of River Deltas in the Anthropocene
Resilience of River Deltas in the Anthropocene
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DOI：
10.1029/2019jf005201
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发表时间：
2020-03-01
影响因子：
3.9
通讯作者：
van Maren, D. S.
中科院分区：
文献类型：
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作者：
Hoitink, A. J. F.;Nittrouer, J. A.;van Maren, D. S.
在全球范围内，由于人类活动的直接和间接影响，三角洲地貌容易发生快速变化。这危及三角洲的生态系统服务，包括防止洪水灾害、促进航行和生物多样性。三角洲形态不稳定的直接表现包括河岸崩塌，可能导致撕裂、持续的河道切割或聚集，以及沉积状况向高浊度条件的变化。尽管过去几十年来对这些主题有了深入的了解，但现有的理解是支离破碎的，形态动力学模型的预测能力也是有限的。潜在恢复力分析工具的进步可能源于改进的模型、连续的观察和新分析技术的应用。进步将受益于各种方法之间的协同作用。经验和数值模型是利用现场观测建立的，反过来，模型模拟可以向天文学家提供在哪里测量的信息。信息论提供了一种系统的方法来测试替代模型概念的现实性。一旦了解了地形动力不稳定现象的关键机制，就可以利用动力系统理论的概念来开发早期预警指标。在开发可靠的工具来设计弹性三角洲时，首要的挑战之一是在多个尺度上关闭沉积物平衡，使地貌动力学模型预测与完全独立的测量相匹配。如此高的雄心壮志很少被采纳，而且迫切需要解决正在进行的全球变化，这些变化导致海平面上升和水库建设导致的泥沙输入减少。
At a global scale, delta morphologies are subject to rapid change as a result of direct and indirect effects of human activity. This jeopardizes the ecosystem services of deltas, including protection against flood hazards, facilitation of navigation, and biodiversity. Direct manifestations of delta morphological instability include river bank failure, which may lead to avulsion, persistent channel incision or aggregation, and a change of the sedimentary regime to hyperturbid conditions. Notwithstanding the in-depth knowledge developed over the past decades about those topics, existing understanding is fragmented, and the predictive capacity of morphodynamic models is limited. The advancement of potential resilience analysis tools may proceed from improved models, continuous observations, and the application of novel analysis techniques. Progress will benefit from synergy between approaches. Empirical and numerical models are built using field observations, and, in turn, model simulations can inform observationists about where to measure. Information theory offers a systematic approach to test the realism of alternative model concepts. Once the key mechanism responsible for a morphodynamic instability phenomenon is understood, concepts from dynamic system theory can be employed to develop early warning indicators. In the development of reliable tools to design resilient deltas, one of the first challenges is to close the sediment balance at multiple scales, such that morphodynamic model predictions match with fully independent measurements. Such a high ambition level is rarely adopted and is urgently needed to address the ongoing global changes causing sea level rise and reduced sediment input by reservoir building.