In order to optimize ship navigation in the macrotidal Gironde Estuary, a recent project funded by the port of Bordeaux aims at better understand and forecast hydrodynamic and fine sediment transport within the estuary. In the framework of this project, a two-dimensional hydro-sedimentary model is built. The model includes hydrodynamic forcings, mixed-sediment transport, and consolidation processes. The harmonic analysis of the astronomical tides reveals a strong distortion of the tidal wave inducing the growth of overtide constituents and the non-significant effect of tide-surge interactions in annual-scale prediction. Depending on hydrological conditions, river discharge can considerably alter the model accuracy due to the migration of the turbidity maximum zone modifying the bottom roughness. Comparison with measurements shows the ability of the model to reproduce suspended-sediment concentrations in the central Estuary. Sensitivity of the model to sediment features has also been discussed in regard of suspended-sediment concentrations and fluid mud deposits. The model will be further coupled with ship squat predictions and a morphodynamic model.

为了优化大潮区吉伦特河口的船舶航行，最近由波尔多港资助的一个项目旨在更好地了解和预测河口内的水动力和细粒沉积物运输。在本项目的框架内，建立了二维水沉积模型。该模型包括水动力强迫、混合沉积物输送和固结过程。天文潮汐的调和分析表明，潮汐波的强烈畸变导致了潮汐成分的增长，潮汐相互作用对年度尺度预测的影响不显着。根据水文条件，由于最大浊度区的迁移改变了底部粗糙度，河流流量可以显着改变模型精度。与测量结果的比较显示了该模型在河口中部再现悬浮沉积物浓度的能力。关于悬浮沉积物浓度和流体泥浆沉积物，还讨论了模型对沉积物特征的敏感性。该模型将进一步与船舶后坐预测和形态动力学模型相结合。