Ice and Permafrost Effects on Delta Morphology and Channel Dynamics
Ice and Permafrost Effects on Delta Morphology and Channel Dynamics
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DOI：
10.1029/2019gl082792
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发表时间：
2019-06-28
影响因子：
5.2
通讯作者：
Rowland, Joel C.
中科院分区：
文献类型：
--
作者：
Lauzon, Rebecca;Piliouras, Anastasia;Rowland, Joel C.
随着永久冻土融化和海冰消退，北极地区正在迅速变化。这些变化直接影响北极河流三角洲，但永久冻土和冰如何改变三角洲水文和沉积物输送还没有得到很好的研究。这种知识差距限制了我们预测这些系统将如何应对持续变暖的能力。我们适应三角洲形态动力学DeltaRCM的复杂性降低的模型，以研究永久冻土和陆地坚冰对三角洲形态和通道动力学的影响。我们发现冰盖和永久冻土降低了航道的流动性，增加了海岸线的粗糙度，并在海上路由和存款更多的沉积物。冰盖也增加了漫滩沉积，增加了陆上三角洲的海拔。我们的模型表明，在气候变暖的永久冻土和冰的损失可能会导致更少的漫滩和近海沉积和更动态和空间分布的水和沉积物通量在北极河流三角洲。
Arctic regions are changing rapidly as permafrost thaws and sea ice retreats. These changes directly affect Arctic river deltas, but how permafrost and ice alter delta hydrology and sediment transport are not well researched. This knowledge gap limits our ability to forecast how these systems will respond to continued warming. We adapt the reduced complexity model of delta morphodynamics DeltaRCM to investigate the influences of permafrost and landfast ice on delta morphology and channel dynamics. We find that ice cover and permafrost decrease channel mobility, increase shoreline roughness, and route and deposit more sediment offshore. Ice cover also enhances overbank deposition, increasing subaerial delta elevations. Our modeling suggests that permafrost and ice loss in a warming climate could lead to less overbank and offshore deposition and more dynamic and spatially distributed fluxes of water and sediment across Arctic river deltas.