Coupling the soil catena to the runoff enigma in Canada's Boreal Plain

将土壤链与加拿大北方平原径流之谜联系起来

• 批准号: RGPIN-2019-06470
• 负责人: Ketcheson, Scott
• 金额: $ 1.82万
• 依托单位: Athabasca University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=738929
• 关键词: Coupling; soil; catena; runoff; enigma

Canada's Boreal Plain stretches from the Rockies to Lake Winnipeg and the Prairies to the northern Taiga ecozones. The amounts of water flowing in its rivers and streams depend on how rainfall is divided between losses to the atmosphere through evaporation and transpiration and that which is stored in its lakes, wetlands, and soils. Determining the redistribution and storage of water between landscapes and waterways is key to understanding stream flows at larger scales. Despite the importance of understanding the flow of water to all aspects of our environment and activities, we do not have enough data to quantify and interpret our studies: runoff in the Boreal Plain remains an enigma. This research aims to understand runoff processes in the mid-to-lower regions of the Athabasca River Basin. However, hydrological measurements for these regions are scant, which limits our ability to interpret and predict runoff variability and trends. Given the large-scale industrial activities in this region, a changing climate, and recent natural disasters, we urgently need to solve this runoff enigma. A soil catena is a sequence of soils found down a slope. The soil hydraulic properties and layering in a catena greatly affect local runoff. Rainfall events on forested hillslopes can cause transient runoff that impacts adjacent wetlands, lakes, and streams. Enhanced hydrological connectivity between hillslopes and wetlands through transient runoff could result in a significant additional mechanism of runoff generation not yet considered. The hydraulic properties of the soils in a catena affect the timing and magnitude of transient runoff, so understanding these properties is crucial to understanding the hydrological processes and stream flows at both the local and regional scales. Since flow pathways affect water quality, transient runoff pathways could also result in geochemical changes that influence the health of downstream ecosystems. The long-term objectives are to identify and understand new mechanisms of water movement within the Boreal Plain and to evaluate their significance for regional-scale runoff. This field-based program will study the transient hydrological connections between wetlands and forested hillslopes. Soil layering along the catenae of multiple hillslopes will be evaluated to assess spatial variability and runoff potential. Laboratory measurements of soil hydraulic properties will complement field results. Innovative hillslope runoff stations at forestland-wetland boundaries will measure lateral hillslope runoff during rainfall events. Subsurface flow pathways along the soil catenae will be determined using tracer tests. These new mechanisms of water movement will be combined with existing hydrological models and compared to observations of water availability and quality within the Athabasca River Basin. This is an important contribution to the conceptualization of water movement in this industrially and ecologically significant region.

加拿大的北方平原从落基山脉延伸到温尼伯湖，从大草原延伸到北部的针叶林生态区。河流和小溪的水量取决于降雨如何分配，其中一部分是通过蒸发和蒸腾流失到大气中的，另一部分是储存在湖泊、湿地和土壤中的。确定水在景观和水道之间的再分配和储存是在更大尺度上理解河流流动的关键。尽管了解水流对我们的环境和活动的各个方面都很重要，但我们没有足够的数据来量化和解释我们的研究：北方平原的径流仍然是一个谜。本研究旨在了解阿萨巴斯卡河流域中下游地区的径流过程。然而，这些地区的水文测量很少，这限制了我们解释和预测径流变化和趋势的能力。考虑到该地区大规模的工业活动、不断变化的气候和最近的自然灾害，我们迫切需要解决这个径流之谜。土壤链是沿斜坡向下发现的一系列土壤。流域土壤的水力特性和分层对当地径流影响很大。在森林覆盖的山坡上的降雨事件会导致短暂的径流，影响到邻近的湿地、湖泊和溪流。通过瞬态径流增强山坡和湿地之间的水文连通性可能导致一个尚未考虑的重要的额外产流机制。流域土壤的水力特性会影响瞬时径流的时间和大小，因此了解这些特性对于了解当地和区域尺度上的水文过程和水流至关重要。由于水流路径影响水质，瞬时径流路径也可能导致影响下游生态系统健康的地球化学变化。长期目标是确定和了解北方平原内水运动的新机制，并评估其对区域尺度径流的重要性。这个基于实地的项目将研究湿地和森林山坡之间的瞬时水文联系。沿着多个山坡链的土壤分层将被评估，以评估空间变异性和径流潜力。土壤水力特性的实验室测量将补充现场结果。在森林-湿地边界的创新山坡径流站将在降雨事件中测量侧向山坡径流。沿着土壤链的地下流动路径将使用示踪剂测试来确定。这些新的水运动机制将与现有的水文模型相结合，并与阿萨巴斯卡河流域内的水可用性和水质观测结果进行比较。这是对这个工业和生态重要地区的水运动概念化的重要贡献。