Fine sediment impacts on water treatability in fire impacted watersheds: Quantification of downstream propagation and water quality threats

细沉积物对受火灾影响的流域水处理能力的影响：下游传播和水质威胁的量化

• 批准号: RGPIN-2020-06963
• 负责人: Stone, Micheal
• 金额: $ 2.19万
• 依托单位: University of Waterloo
• 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=741515
• 关键词: Fine; sediment; impacts; water; treatability

Forests are the primary source of drinking water for > 58% of the largest urban and rural communities as well as most Indigenous communities in Canada. Ironically, the high quality of these water resources make them vulnerable to severe large scale landscape disturbance such as those produced by wildfire. Climate associated changes in fire weather conditions over the past two decades have resulted in rapidly increasing occurrence, extent, and severity of major wildfire disturbances in critical forested source water regions of western North America. The threat of wildfire on sediment and associated nutrient dynamics in rives draining forested regions may pose a real risk to water supply and ecosystem services in many regions in Canada and across the globe. Despite the economic and environmental significance of wildfire and threats to the provision of safe drinking water, relatively few studies have examined the propagation of fine sediment in rivers draining burned watersheds and the delivery of these materials to reservoirs. Little is known about whether this deposited bottom sediment is a sink or source of phosphorus or if it has the potential to proliferate the growth of cyanobacteria which can challenge water treatment processes. Given that forested snow melt dominated slopes of the eastern slopes of the Rocky Mountains are critical water supply regions in Canada and the United States, knowledge gained from this research is relevant to water suppliers where source waters generally originate from forested landscapes. Results of the proposed research will improve knowledge of the transport processes and water quality impacts of post fire sediment and associated phosphorus in rivers at the large basin scale and evaluate the risk to water quality in downstream environments such as lakes and reservoirs. Knowledge gained from the proposed research will provide scientific insights to inform reservoir management strategies to evaluate the risk of fine sediment from wildfires to water treatability and related challenges to the provision of safe drinking water.

森林是加拿大超过 58% 的最大城市和农村社区以及大多数原住民社区的主要饮用水源。具有讽刺意味的是，这些水资源的高质量使它们很容易受到严重的大规模景观干扰，例如野火造成的干扰。过去二十年来，与气候相关的火灾天气条件变化导致北美西部关键森林水源地区重大野火干扰的发生率、范围和严重程度迅速增加。野火对森林地区河流的沉积物和相关营养动态的威胁可能会对加拿大和全球许多地区的供水和生态系统服务构成真正的风险。尽管野火具有经济和环境意义，并对安全饮用水的供应构成威胁，但相对较少的研究考察了排出烧毁流域的河流中细小沉积物的传播以及这些物质向水库的输送。人们对这种沉积的底部沉积物是否是磷的汇或源，或者它是否有可能促进蓝藻生长的潜力知之甚少，这对水处理过程提出了挑战。鉴于落基山脉东坡以森林融雪为主的斜坡是加拿大和美国的关键供水区域，从这项研究中获得的知识与水供应商相关，因为水源水通常源自森林景观。拟议研究的结果将提高对大流域规模河流中火后沉积物和相关磷的传输过程和水质影响的了解，并评估湖泊和水库等下游环境的水质风险。从拟议研究中获得的知识将为水库管理策略提供科学见解，以评估野火造成的细小沉积物对水可处理性的风险以及提供安全饮用水的相关挑战。