Studies of fluvial sediment transport, sedimentation and river morphology

该方案的目标是了解控制冲积河道(即在其本身的沉积物中自形成的河道)发展的因素，其中泥沙输送是最重要的。四种工作风格相辅相成，允许学生自由选择他们的工作风格：(I)泥沙输送和沉积的水槽实验；(Ii)泥沙输送和河道几何的现场测量；(Iii)河道对泥沙输送的长期研究；以及(Iv)关于河流和地貌演变的理论。我们已经开始了泥沙输送中的颗粒分选(与法国IRSTEA研究所合作)和谢尔兹泥沙夹带标准的实验。前者提出了一种新的观点，认为泥沙运移是一种颗粒现象。后者是泥沙运动理论的基础，但80年来一直没有受到挑战。我们认为Shields数是一个河床状态参数，而不是简单的颗粒迁移率，它需要研究泥沙结构布置对河床的影响，而Shields没有考虑到这一点。我们继续研究和平河对20世纪60年代水电生产调流的响应，特别是应用我们发展的合理河势理论来预测河道演变的新的平衡形式。我们还将延长航道调整的现场记录，目前已有40多年的时间，将在2014年重新检查我们的纪念性横断面。我们将继续研究弗雷泽河下游的砾石涌入和河床淤积问题，这似乎是19世纪砂矿开采的遗留问题。特别是，我们正在调查覆盖沙运输对估计的总体泥沙预算的影响。我们还利用新的声学技术，开始研究不列颠哥伦比亚省米申市弗雷泽河的悬浮泥沙输移，以及远河口航道的泥沙输移。我们将继续利用弗雷泽河和奇利瓦克河的数据，在更长的时期和更长的距离内继续进行泥沙输送模型的关键研究。弗雷泽的研究代表了进一步证实砂矿开采遗产的一种尝试。奇利瓦克的研究试图将土地管理成果的物理分析方法扩展到小流域的范围之外，它主要局限于小流域。这些研究也有助于理解现代过程的时间尺度和构造演化的时间尺度之间的中期景观演变，以及中等景观区域(数千平方公里量级)的景观演变，这些都是被很大程度上忽视的重要尺度。这些工作中的许多工作，特别是关于和平河和弗雷泽河的工作，对于河流管理具有直接的意义，前者与预计的进一步水电开发有关，后者与防洪有关。事实上，一些科学的动机是我们被要求解决与这些问题有关的实际问题。

The objective of the program is to understand the factors governing the development of alluvial river channels (i.e., channels self-formed in their own sediment deposits), amongst which sediment transport is paramount. Four styles of work provide complementary results and allow students freedom to select their style of work: (i) flume experiments on sediment transport and sedimentation; (ii) field measurements of sediment transport and channel geometry; (iii) long-term studies of channel response to sediment transport; and (iv) theory about river and landscape evolution. We have initiated experiments on grain sorting in bedload transport (in cooperation with the French institute IRSTEA) and on Shields’ entrainment criterion for sediment. The former entails a novel view of sediment transport as a granular phenomenon. The latter is the foundation for sediment transport theory but has remained unchallenged for 80 years. We consider the Shields number to be a bed-state parameter, not simply a grain mobility number, which entails investigating the effect of structural arrangements of sediment on the stream bed, not considered by Shields.We continue to study the response of Peace River to flow regulation in the 1960s for hydropower production, in particular to apply our developed rational regime theory to predict the new equilibrium form toward which the channel is evolving. We will also extend our field record of channel adjustment, which is now more than 40 years long, by resurveying our monumented cross sections in 2014. We will continue to study the problems of gravel influx and channel bed aggradation in lower Fraser River, which appears to be a legacy of 19th century placer mining. In particular, we are investigating the effect of cover sand transport on the estimated overall sediment budget. We have also initiated studies of suspended sediment transport in Fraser River at Mission, BC, using novel acoustic techniques and of sand transport in the distal estuarine channel. We will continue critical studies of sediment transport modelling over extended periods and distances using data from Fraser and Chilliwack rivers. The Fraser study represents an attempt to further substantiate the placer mining legacy. The Chilliwack study seeks to expand methods for physical analysis of land management outcomes beyond the scale of small drainage basins, to which it has mainly been limited. These studies are also a contribution toward understanding landscape evolution in the intermediate term between time scales of contemporary process and those of tectonic evolution, and over intermediate landscape areas (order thousands of square kilometres), important scales that have largely been neglected.Much of this work, especially on Peace and Fraser rivers, has immediate significance for river management, in the former case in relation to projected further hydropower development and in the latter in relation to flood protection. Indeed, some of the science is motivated by practical questions we have been asked to resolve in relation to these issues.