Deciphering the evolutionary history and depositional processes of meandering rivers

破译蜿蜒河流的演化历史和沉积过程

• 批准号: RGPIN-2018-06026
• 负责人: Durkin, Paul
• 金额: $ 1.82万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=714039
• 关键词: Deciphering; evolutionary; history; depositional; processes

Rivers are essential aspects of transport systems that deliver sediment from erosional highlands to depositional basins. Rivers also play a significant role in society, from irrigation and navigation, to wildlife habitat and sources of drinking water. Drastic changes in river system behavior can also significantly impact infrastructure and human lives (e.g., floods). There is considerable uncertainty in predictions of the magnitude and frequency of future flood events and how river systems will respond to environmental change. Investigation into the deposits of past floods and the evolutionary history of river systems provides insight into these uncertainties. By documenting ongoing processes in modern river systems, we learn how and under what conditions sediment is deposited, and define criteria for recognition of associated sediments in the depositional record. The proposed research program aims to better understand how rivers respond to internal (e.g., floods) and external (e.g., climate) forcing by studying the processes of modern rivers, and their resulting deposits in the fossilized record. The surficial sediment cover of southwestern Manitoba records the de-glaciation history of the area, beginning around 20,000 years ago. This includes the deposition of the Assiniboine Delta into glacial Lake Agassiz, which once covered much of the province. As the lake drained, fluvial incision into the deltaic deposits created the modern Assiniboine River valley. It is within these river deposits that an archive of past floods, changing lake levels, and varying climatic conditions is recorded. The proposed research program will investigate these deposits to yield insight into the magnitude and frequency of flood events, and more generally, how rivers respond to changing Earth conditions. To expand the window of observation, fossilized river deposits exposed in the “badlands” of southeastern Alberta will also be examined. Ancient fluvial deposits are an underutilized record of changing Earth conditions, and they represent a much longer archive (>104 yrs) than human observation. This integrated analysis will provide a holistic understanding of river processes and sedimentary products, which will inform predictions of future flood events and river response to a changing climate. The proposed research program will train 14 HQPs and produce results that are directly applicable to flood mitigation efforts, as well as the development of oil and gas resources contained in fluvial deposits.

河流是将沉积物从侵蚀高地输送到沉积盆地的重要组成部分。河流在社会中也发挥着重要作用，从灌溉和航运到野生动物栖息地和饮用水源，河流系统行为的剧烈变化也会产生重大影响。基础设施和人类生活（例如洪水）对未来洪水事件的规模和频率以及河流系统将如何应对环境变化的预测存在很大的不确定性。洞察这些通过记录现代河流系统中正在进行的过程，我们了解沉积物如何以及在什么条件下沉积，并定义沉积记录中相关沉积物的识别标准。拟议的研究计划旨在更好地了解河流如何响应内部（例如，沉积物）。通过研究现代河流的过程及其在化石记录中产生的沉积物，来了解洪水）和外部（例如气候）强迫。 马尼托巴省西南部的地表沉积物记录了该地区的冰川消融历史，该历史始于大约 20,000 年前，其中包括阿西尼博因三角洲沉积到阿加西冰川湖中，该湖曾经覆盖该省的大部分地区。三角洲沉积物的切割形成了现代的阿西尼博因河谷。正是在这些河流沉积物中，记录了过去的洪水、变化的湖水位和变化的气候。拟议的研究计划将调查这些沉积物，以深入了解洪水事件的严重程度和频率，以及更广泛的了解河流如何应对不断变化的地球条件。古代河流沉积物是地球条件变化的未充分利用的记录，它们代表了比人类观测更长的档案（> 104 年），这种综合分析将提供对河流过程和沉积的整体了解。拟议的研究计划将培训 14 个 HQP，并产生可直接应用于防洪工作以及开发其中所含石油和天然气资源的结果。河流沉积物。