Deciphering the evolutionary history and depositional processes of meandering rivers

河流是将沉积物从侵蚀高地输送到沉积盆地的运输系统的重要方面。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来源。河流系统行为的急剧变化也会显著影响基础设施和人类生活（例如，洪水）。在预测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方面存在相当大的不确定性。对过去洪水沉积物和河流系统演变历史的调查提供了对这些不确定性的深入了解。通过记录现代河流系统中正在进行的过程，我们了解沉积物是如何沉积的，以及在什么条件下沉积的，并定义在沉积记录中识别相关沉积物的标准。拟议的研究计划旨在更好地了解河流如何应对内部（例如，洪水）和外部（例如，马尼托巴西南部的表层沉积物覆盖层记录了该地区约2万年前开始的冰川消退历史。这包括阿西尼博因三角洲沉积到冰川湖阿加西斯，这曾经覆盖了该省的大部分地区。随着湖水的流失，河流进入三角洲沉积物，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，变化的湖泊水位和变化的气候条件。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规模和频率，以及更一般地说，河流如何应对不断变化的地球条件。为了扩大观测范围，还将对阿尔伯塔东南部“荒地”暴露的风化河流沉积物进行检查。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察更长的档案（>104年）。这种综合分析将提供对河流过程和沉积产物的全面了解，这将为未来洪水事件的预测和河流对气候变化的反应提供信息。拟议的研究计划将培训14名HQP，并产生直接适用于洪水缓解工作以及河流沉积物中石油和天然气资源开发的结果。

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.