The colluvial dimension of mountain drainage basins

山地流域崩积体尺寸

• 批准号: 355835-2008
• 负责人: Brardinoni, Francesco
• 金额: $ 1.38万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=402721
• 关键词: colluvial; dimension; mountain; drainage; basins

The proposed research focuses on colluvial sediment dynamics in mountain environments of British Columbia. The overall objective is to advance the present understanding of the colluvial sediment flux and colluvial-alluvial interactions, how these affect the current functioning, and the long-term evolution of mountain drainage basins. The research will investigate hillslopes and channels in a novel, multi-scale framework that addresses the following questions: (i) what controls the colluvial sediment flux associated with landslides and debris flows? (ii) How does the associated sediment supply affect the functioning of mountain channels? (iii) How does the large-scale structure of mountain drainage basins affect colluvial activity and colluvial-alluvial interaction? Research will be conducted by combining the use of aerial photographs, digital elevation models, and field data. The first question will be addressed via examination of the spatial and temporal controls on landslide magnitude-frequency relations and their associated feedback on topography. The second question, which will use information derived from landslide inventories, will be addressed via quantitative characterization of (i) colluvial channels in terms of longitudinal profiles, cross-sections, wood load, grain-size, and indices of stream power; and (ii) spatial and temporal variability of colluvial-alluvial interactions. The third question will be addressed in the context of landscape response to external forcing that cause landslide disturbance, and will exploit data derived from the previous two research components. Overall, this research will be invaluable for understanding environmental impacts of forest practices on mountain streams, drainage basin sediment dynamics, and the influence of landsliding on the evolution of river valleys. In particular, we will be able to document where in the channel network landslide disturbance preferentially occurs and sediment stores, for how long material remains on storage, and the efficiency of fluvial reworking. Last but not least, we expect to improve our understanding on how the structure of drainage basins controls landslide sediment production and interaction with rivers.

这项研究的重点是不列颠哥伦比亚省山区环境中的堆积沉积动力学。总体目标是促进目前对堆积沉积通量和堆积-冲积相互作用的理解，这些如何影响目前的功能，以及山区流域盆地的长期演变。这项研究将在一个新的、多尺度的框架内调查山坡和渠道，以解决以下问题：(1)是什么控制了与滑坡和泥石流有关的堆积泥沙通量？(2)相关的泥沙供应如何影响山区河道的功能？(3)山地流域的大尺度结构如何影响堆积活动和堆积-冲积相互作用？研究将结合航空照片、数字高程模型和现场数据进行。第一个问题将通过研究滑坡震级-频率关系的空间和时间控制以及它们对地形的相关反馈来解决。第二个问题将使用从滑坡调查中获得的信息，将通过定量描述(I)堆积河道的纵向剖面、横截面、木材负荷、颗粒大小和河流功率指数；以及(Ii)堆积-冲积相互作用的空间和时间变异性来解决。第三个问题将在引起滑坡扰动的外部强迫的背景下讨论，并将利用来自前两个研究组成部分的数据。总体而言，这项研究对于了解森林做法对山间溪流的环境影响、流域沉积物动力学以及滑坡对河谷演变的影响将是非常宝贵的。特别是，我们将能够记录河网中滑坡干扰优先发生的位置和泥沙储存，材料储存多长时间，以及河流返工的效率。最后但同样重要的是，我们希望提高我们对流域结构如何控制滑坡泥沙产生以及与河流相互作用的理解。