Erosional Sorting of Fine Marine Sediments

细小海洋沉积物的侵蚀分选

• 批准号: 138535-2012
• 负责人: Hill, Paul
• 金额: $ 3.27万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=569360
• 关键词: Erosional; Sorting; Fine; Marine; Sediments

The transport of fine sediment in intertidal waters affects the health and sustainable uses of the coastal zone in Canada. The response of the shoreline to sea level rise, navigability of coastal waters and exposure of humans and other organisms to sediment-bound contaminants all depend on fine sediment transport. To complicate matters, all of these effects are tied to the sortability of fine marine sediment, which is not well understood. The goal of this research is to improve understanding of the factors that affect the erosional sortability of fine marine sediment and ultimately to incorporate this understanding into models of fine sediment transport. Conceptually, erosional sortability simply describes how easy or difficult it is to separate particles of different sizes from one another during erosion of sediment from the seabed. "Fine sediment" is the term applied to sediments with mean particle diameters less than 63 micrometres. For decades, sedimentologists treated fine sediment particles as non-sortable, a hypothesis that led to poor predictions of fine sediment size distributions and concentrations in the seabed and in suspension. It also led to crude models for the mobility of particle-attached substances. Recent studies have shown, however, that fine sediments are sortable, but that the sortability depends on the interaction of biotic and abiotic factors. This research will focus on five factors that are likely to dominate the sortability of fine marine sediments: sediment texture, sediment water content, abundance of sediment-attached (epipelic) diatoms, abundance of bacteria, and concentration and properties of sediment exopolymeric substances (EPS). These factors will be examined with a combination of field studies, laboratory experiments, and modeling.

潮间水中细沉积物的运输会影响加拿大沿海地区的健康和可持续用途。海岸线对海平面上升的反应，沿海水域的通航以及人类和其他生物暴露于沉积物结合的污染物中的反应都取决于精细的沉积物运输。使事情复杂化，所有这些影响都与精细的海洋沉积物的可分解性有关，这尚未得到充分理解。 这项研究的目的是提高对影响细海洋沉积物侵蚀性可分解性的因素的理解，并最终将这种理解纳入精细沉积物传输模型中。 从概念上讲，侵蚀性可分解性简单地描述了在侵蚀沉积物与海床时，将不同大小的粒子彼此分开多么容易或困难。 “细沉积物”是应用于平均颗粒直径小于63微米的沉积物的术语。几十年来，沉积物学家将精细的沉积物颗粒视为不可分类的假设，这使人们对海床和悬浮液的细小沉积物尺寸分布和浓度的预测不佳。这也导致了粒子附着物质的迁移率的粗制模型。然而，最近的研究表明，精细的沉积物是可分类的，但是 可分解性取决于生物和非生物因素的相互作用。 这项研究将集中在可能主导细海洋沉积物的可分解性的五个因素上：沉积物质地，沉积物水含量，丰富的沉积物连接（表皮）硅藻，丰富的细菌以及沉积物外聚物物质的浓度和特性（EPS） ）。这些因素将通过现场研究，实验室实验和建模的结合来检查。