River dynamics and process-based restoration of fluvial systems

河流动力学和基于过程的河流系统恢复

• 批准号: RGPIN-2022-04659
• 负责人: Biron, Pascale
• 金额: $ 3.72万
• 依托单位: Concordia University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=754945
• 关键词: River; dynamics; process; based; restoration

River systems are under considerable pressure due to human impacts and global environmental changes. As we enter the United Nations Decade on Ecosystem Restoration, it is increasingly recognized that river management approaches must move away from form-based restoration and hard-engineering structures that maintain rivers in a fixed position. The long-term objective of the research program is to advance our understanding of the links between river dynamics and river ecosystems to support the development of sustainable, process-based river restoration. Such restoration involves leaving sufficient space for flooding and erosion processes to operate, which is particularly critical in a context of climate change where increased variability in discharge is expected in the coming decades. This long-term objective will be reached through the combination of, and interactions between, numerical modelling and laboratory and field experimentation. The increased availability of LiDAR high-resolution digital elevation models (DEM), with for example data for the entire southern Quebec now freely accessible, will also greatly help in reaching this objective. The short-term objectives are to 1) develop tools to help predict effects of implementing a freedom space on future river channel evolution; 2) assess the impact of reconnecting former meanders in straightened agricultural streams in various geomorphological contexts and 3) investigate the role of confluence zones as key control points in fluvial system restoration. The scientific approach of this research program is based on the collection of field data at several river reaches in different geomorphological contexts and in a range of anthropogenic disturbances, including agricultural watersheds affected by channelization, dredging and bank stabilization. Field measurements include detailed bed topography, velocity, piezometer monitoring, stage and discharge, and will make use of drone imagery analysis tools. The field component is combined with experiments conducted at the new Outdoor Experimental River Facility (OERF) at Université de Sherbrooke. Geographical Information System (GIS) analysis of LiDAR data is a central part of my research program, with hydrogeomorphological tools designed to examine both mobility and flood processes that will be further developed. The confluence zones will receive particular attention to further our understanding on how these zones affect the physical heterogeneity of the main channel and to pursue detailed analysis on the (so far) underestimated role of density difference between the tributary and main channel. This program will allow significant progress in establishing an expertise in river management based on hydrogeomorphological concepts to tackle major environmental problems in a range of rivers, and on developing GIS and modelling tools to better inform river managers about sustainable process-based restoration approaches.

由于人类的影响和全球环境变化，河流系统受到相当大的压力。随着我们进入联合国生态系统恢复十年，人们日益认识到，河流管理办法必须摆脱基于形式的恢复和将河流维持在固定位置的硬工程结构。该研究计划的长期目标是促进我们对河流动力学和河流生态系统之间联系的理解，以支持可持续的，基于过程的河流恢复的发展。这种恢复需要为洪水和侵蚀过程留下足够的空间，这在气候变化的背景下尤其重要，因为预计未来几十年排放量的变化将增加。这一长期目标将通过数值模拟与实验室和实地试验相结合并相互作用来实现。激光雷达高分辨率数字高程模型（DEM）的可用性增加，例如整个魁北克南部的数据现在可以免费获取，也将大大有助于实现这一目标。短期目标是：1）开发工具，以帮助预测实施自由空间对未来河道演变的影响; 2）评估在各种地貌背景下重新连接变直的农业河流中的前河曲的影响; 3）调查汇流区作为河流系统恢复关键控制点的作用。该研究项目的科学方法是基于在不同地貌背景下和一系列人为干扰下收集多个河流河段的实地数据，包括受渠化、疏浚和河岸稳定影响的农业流域。实地测量包括详细的河床地形、流速、测压仪监测、水位和流量，并将利用无人机图像分析工具。现场组件相结合，在新的室外实验河设施（OERF）在舍布鲁克大学进行的实验。LiDAR数据的地理信息系统（GIS）分析是我的研究计划的核心部分，水文地貌工具旨在研究流动性和洪水过程，将进一步发展。汇流区将受到特别关注，以进一步了解这些区域如何影响主河道的物理异质性，并对（迄今为止）被低估的支流和主河道之间密度差异的作用进行详细分析。该计划将允许在建立基于水文地貌概念的河流管理专业知识方面取得重大进展，以解决一系列河流的主要环境问题，并开发地理信息系统和建模工具，以更好地告知河流管理人员可持续的基于过程的恢复方法。