Unstructured-mesh modeling of the Congo river-to-sea continuum
Unstructured-mesh modeling of the Congo river-to-sea continuum
复制标题
刚果河海连续体的非结构化网格建模
DOI：
10.1007/s10236-016-0939-x
复制
发表时间：
2016
期刊：
影响因子：
2.3
通讯作者：
Claire Channelière
中科院分区：
文献类型：
--
作者：
Y. L. Bars;Valentin Vallaeys;É. Deleersnijder;E. Hanert;L. Carrère;Claire Channelière
刚果河拥有世界第二大流量和最宽的水文流域之一，在当地和全球都具有重要意义。然而，与亚马逊、尼罗河、长江或密西西比河等其他大河相比，对其水文学的研究相对较少。因此，这项研究的目标是帮助填补这一空白，并提供第一个高分辨率的刚果河-河口-沿海海洋连续体的模拟。为此，我们使用了一种非连续Galerkin有限元海洋模型，它在非结构网格上求解二维平均水深浅水方程。为了确保从河流到沿海海洋的平稳过渡，我们考虑了一个既包括水文过程又包括沿海海洋过程的模型。建立这一模型的一个重要困难是寻找数据来对其进行参数化和验证，因为这是一个相当偏远和研究不足的领域。因此，这项研究的一项重要努力是建立一种方法，以利用所有可用的数据来源，包括必须数字化的海图。然后，已参照高程数据库验证了模型曲面高程。模型结果表明，在河口附近存在以前从未记录过的旋涡。通过模拟拉格朗日粒子的输运和计算水龄，进一步研究了这些涡旋对刚果河动力学的影响。
With the second largest outflow in the world and one of the widest hydrological basins, the Congo River is of a major importance both locally and globally. However, relatively few studies have been conducted on its hydrology, as compared to other great rivers such as the Amazon, Nile, Yangtze, or Mississippi. The goal of this study is therefore to help fill this gap and provide the first high-resolution simulation of the Congo river-estuary-coastal sea continuum. To this end, we are using a discontinuous-Galerkin finite element marine model that solves the two-dimensional depth-averaged shallow water equations on an unstructured mesh. To ensure a smooth transition from river to coastal sea, we have considered a model that encompasses both hydrological and coastal ocean processes. An important difficulty in setting up this model was to find data to parameterize and validate it, as it is a rather remote and understudied area. Therefore, an important effort in this study has been to establish a methodology to take advantage of all the data sources available including nautical charts that had to be digitalized. The model surface elevation has then been validated with respect to an altimetric database. Model results suggest the existence of gyres in the vicinity of the river mouth that have never been documented before. The effect of those gyres on the Congo River dynamics has been further investigated by simulating the transport of Lagrangian particles and computing the water age.