Bugs in engineering? Understanding the transport of cohesive sediment in aquatic systems

越来越多的计算机被用来帮助预测拟议的基础设施项目对环境的影响，例如拆除大坝或修建桥梁。然而，计算机模拟的用处仍然受到我们对自然系统如何工作的理解以及我们如何用数字表示自然的知识和经验的限制。水动力和泥沙运动模型是更好地了解水动力环境(水流速度、水流方向等)之间关系的有力工具。以及来自河道的物质的侵蚀和沉积。他说，拟议的研究旨在进一步了解Petitcodiac河口附近Shepody湾生物丰富的泥滩的动态侵蚀特性。这些泥滩在国际上被视为重要地点，因为每年有200多万只候鸟来这里品尝丰富的泥虾。建议的Petitcodiac河堤道的部分开放将增加河口内的潮汐能量，并可能对泥滩产生影响；这一地点将被用作支持这项研究的案例研究。以前对堤道开通进行数值模拟的尝试没有考虑到堤道下游泥滩的侵蚀或堆积上是否存在生物生物。因此，对环境保护规划的用处是有限的。建议的研究包括两个部分：1)调查宏观生物的存在对粘性河口沉积物侵蚀速度的影响；2)推进模拟细粒粘性沉积物侵蚀和命运的预测输运模型的开发，特别是纳入生物有机体的存在的影响。研究将增进我们对这些过程的理解，导致更全面和准确的模型，可以更好地为决策者和规划者提供支持。

More and more, computers are being used to help predict the environmental impacts of proposed infrastructure projects, such as the removal of dams or the building of bridges.  However, the usefulness of computer modelling is still limited by our understanding of how natural systems work and our knowledge and experience with how to represent nature with numbers. Hydrodynamic and sediment transport modelling is a powerful tool to better understand the relationship between the hydrodynamic environment (water velocity, direction, etc.) and the erosion and deposition of material from a river channel.       The proposed research seeks to further the understanding of the dynamic erosional properties of biologically-rich mudflats in Shepody Bay near the Petitcodiac River Estuary.  These mudflats are considered as important sites internationally, as they are visited every year by more than two million migratory birds that feast on the abundant mudshrimp.  The proposed partial opening of the Petitcodiac River causeway will increase the tidal energy within the estuary and may have impacts on the mudflats; this site will be used as a case study to support the research.  Previous attempts to numerically model the opening of the causeway have not considered the presence of biological organisms on the eroding or building-up of mudflats downstream of the causeway.  As a result, there is a limit to the usefulness for environmental protection planning.   The proposed research has two components: 1) to investigate the impact of the presence of macro-organisms on the erosion rate of cohesive estuarine sediments; 2) to advance the development of predictive transport models for simulating the erosion and fate of fine cohesive sediments, and in particular incorporate the impact of the presence of biological organisms.  The research will enhance our understanding of these processes, leading to a more comprehensive and accurate model that can better support decision makers and planners.