Influence Mechanism of Geomorphological Evolution in a Tidal Lagoon with Rising Sea Level
Influence Mechanism of Geomorphological Evolution in a Tidal Lagoon with Rising Sea Level
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DOI：
10.3390/jmse10010108
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发表时间：
2022-01
影响因子：
2.9
通讯作者：
C. Kuang;Jiadong Fan;Zhichao Dong;Q. Zou;X. Cong;Xuejian Han
中科院分区：
文献类型：
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作者：
C. Kuang;Jiadong Fan;Zhichao Dong;Q. Zou;X. Cong;Xuejian Han
潮汐泻湖系统具有多种环境、社会和经济影响。为探讨潮湖地貌演化的影响机制，采用MIKE水-形态动力学模型，对典型潮湖七里海进行了临界侵蚀剪切应力、临界沉积剪切应力、泥沙沉降速度和初始河床高程的影响评估。模拟结果表明，在没有输沙补给的情况下，当临界侵蚀、沉积剪应力或泥沙沉降速度增大时，会形成地形稳定的潮网。这种平衡状态可以定义为净侵蚀变化变化不大，这是由于侵蚀和沉积效应的相互作用而实现的。此外，初始河床高程的影响取决于最低潮位。当初始河床高程低于最低潮位时，潮网趋于充分发育。Spearman相关分析表明，地貌演化对临界侵蚀剪应力或沉积剪应力的影响比对泥沙沉降速度和初始河床高程的影响更为敏感。在潮汐泻湖的长期演变中，指数海平面上升比线性或抛物线海平面上升对侵蚀的影响更大。
A tidal lagoon system has multiple environmental, societal, and economic implications. To investigate the mechanism of influence of the geomorphological evolution of a tidal lagoon, the effect of critical erosion shear stress, critical deposition shear stress, sediment settling velocity, and initial bed elevation were assessed by applying the MIKE hydro- and morpho-dynamic model to a typical tidal lagoon, Qilihai Lagoon. According to the simulation results, without sediment supply, an increase of critical erosion, deposition shear stress, or sediment settling velocity gives rise to tidal networks with a stable terrain. Such an equilibrium state can be defined as when the change of net erosion has little variation, which can be achieved due to counter actions between the erosion and deposition effect. Moreover, the influence of the initial bed elevation depends on the lowest tidal level. When the initial bed elevation is below the lowest tidal level, the tidal networks tend to be fully developed. A Spearman correlation analysis indicated that the geomorphological evolution is more sensitive to critical erosion or deposition shear stress than sediment settling velocity and initial bed elevation. Exponential sea level rise contributes to more intensive erosion than the linear or the parabolic sea level rise in the long-term evolution of a tidal lagoon.