Assessing and restoring the resilience of urban stream networks

评估和恢复城市河流网络的弹性

• 批准号: 463321-2014
• 负责人: MacVicar, Bruce
• 金额: $ 14.43万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Strategic Projects - Group
• 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=577042
• 关键词: Assessing; restoring; resilience; urban; stream

The proposed research is motivated by the uncertainty in decision making processes faced by strategic partners in the management of urban stream networks. The basic problem is that urbanization increases the volume of surface runoff and the magnitude of peak discharges during floods. This water must be routed through stream networks that developed under much more moderate flow regimes. Widespread physical degradation and loss of ecosystem services such as clean air and water, aesthetics, and recreational and educational opportunities lead to what is called the "urban stream syndrome". Stormwater management and stream restoration are two available but limited techniques for the issue, but they often do not work as intended despite significant costs, and climate change poses a significant additional threat. The research gap we aim to address is the response of channel bed sediment to floods in urban creeks under different management scenarios. The field research will focus on three sites in the Greater Toronto Area, namely Wilket Creek, developed without stormwater management, Morningside Creek, developed with end-of-pipe stormwater management, and Ganetsekaigon Creek, slated for development in the coming decades. Ganetsekaigon Creek is currently home to a healthy population of Redside Dace, which is listed as an endangered species in Ontario. Quantifying the sedimentary response is critical for understanding ecosystem resilience in these systems because the sediments comprising the river bed are the physical habitat of the algae and benthic invertebrates that underpin the food web in aquatic and riparian ecosystems. The issues surrounding sediment supply and routing through a channel have received little attention in the practice of urban stream management and we will attempt to address this problem with innovative field work, laboratory studies on sediment dynamics, and the development of a decision making support tool through embedded research with our partners. We will also assess a new approach based on sediment supply management that has the potential to rebalance the physical stream network and restore ecosystem services.

本研究的动机是战略合作伙伴在城市河流网络管理中所面临的决策过程中的不确定性。基本问题是，城市化增加了洪水期间地表径流量和洪峰流量的大小。这些水必须通过在更温和的流量条件下发展起来的水系网络。广泛的自然退化和生态系统服务（如清洁的空气和水、美学、娱乐和教育机会）的丧失导致了所谓的“城市河流综合症”。对于这个问题，雨水管理和溪流恢复是两种可用但有限的技术，尽管成本高昂，但它们往往无法发挥预期的作用，而且气候变化构成了重大的额外威胁。