Numerical Investigation of River Discharge and Tidal Variation Impact on Salinity Intrusion in a Generic River Delta Through Idealized Modelling
Numerical Investigation of River Discharge and Tidal Variation Impact on Salinity Intrusion in a Generic River Delta Through Idealized Modelling
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DOI：
10.1007/s12237-022-01109-2
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发表时间：
2022-09
影响因子：
2.7
通讯作者：
C. Matsoukis;L. Amoudry;L. Bricheno;N. Leonardi
中科院分区：
文献类型：
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作者：
C. Matsoukis;L. Amoudry;L. Bricheno;N. Leonardi
由于海平面上升，三角洲系统的盐度预计在不久的将来会增加。这将造成严重的环境后果，因为盐度可能对农业、水产养殖和人类消费有害。潮汐动力学在调节河流三角洲的盐度方面很重要。然而，不同的潮汐振幅对三角洲盐度的影响仍存在不确定性。本文通过三维理想化模型研究了不同潮汐振幅对三角洲盐度时空分布的影响。采用相同的过程线和不同的潮差进行了数值模拟。潮汐影响和河流占主导地位的情况下被认为是。结果表明，在河流占主导地位的情况下，潮汐振幅的小幅增加或低潮态的情况下，可以对盐碱化产生积极的影响。潮汐引起的混合有助于增加淡水面积和体积。三角洲的水在代表微潮状态的情况下保持较长时间的新鲜。潮汐振幅进一步增加到中潮和大潮水平，会逆转这些影响，减少淡水面积和体积。结果被用来测试盐度如何与渠道订单和河流流量在潮汐的存在下。这些相关性更多地受水深测量而不是潮汐力的控制。这项研究提供了重要的见解如何在潮差的变化可能会影响时空盐度分布的三角洲。
Salinity in deltaic systems is expected to increase in the near future due to sea level rise. This will cause severe environmental consequences because salinity can be detrimental to agriculture, aquaculture and human consumption. Tidal dynamics are important in regulating salinity in river deltas. However, there is still uncertainty about the influence of different tidal amplitudes on deltas’ salinity. This paper investigates the impact of various tidal amplitudes on the spatiotemporal salinity distribution in deltas through three-dimensional idealized modelling. Numerical simulations are carried out with a common hydrograph and different tidal ranges. Both tide-influenced and river-dominated cases were considered. Results suggest that small increases in the tidal amplitude in river-dominated or low tidal regimes cases can have positive effects against salinization. Tide-induced mixing helps to increase freshwater areas and volumes. The water in the delta remains fresh for longer periods in scenarios representative of microtidal regimes. Further increases in the tidal amplitude to meso- and macrotidal levels reverse these effects and reduce freshwater areas and volumes. Results were used to test how salinity correlates with channel orders and river discharge in the presence of tides. These correlations are controlled more by bathymetry than tidal forcing. This study provides important insights into how changes in tidal range could impact spatiotemporal salinity distributions in deltas.