Accounting for Environmental and Life Safety Risks of Reservoir Releases in Regulated Watersheds: Reservoir and Land Management

水库溢流和溃坝构成重大洪水风险，对下游经济和生命安全造成影响。这些系统所形成的人工湖和极端或调节的河流流量可能造成不可逆转的环境破坏，威胁水生生态系统。周边地区的土地利用方式可能通过对流域水文和定居模式的影响以及非点源污染物的释放而加剧这种风险。考虑到潜在的严重后果，在面对气候变化和其他不确定因素的情况下，需要有方法提供合理和透明的基础来评估这种风险，并在水库运营和流域管理决策中考虑这些风险。该项目：i)发展水质模型，以确定下游环境影响及其与鱼类种群和栖息地、水库流出物的相互作用，并制定评估此类后果风险的措施；Ii)制定水库运行决策框架，考虑气候和土地利用变化带来的环境、渔业和生命安全风险；iii)开发方法，以解释估算土地使用对环境和洪水后果的不确定性。所开发的模型和方法将旨在确定受风险影响的程度，确定系统在短期或长期内从风险中恢复的能力，表明后果何时可能不可逆转，并说明降水模式和土地利用做法的变化。它们可用于支持水库系统的规划和运作以及区域参与性用水规划过程。研究结果将直接有利于电力和供水公司管理其风险组合和维持其运营许可，并有利于区域用水管理人员和社区评估各种水和土地使用的利益与水资源短缺、环境破坏和系统水文变化的成本之间的权衡。加强对大额资产的负责任管理，提高公共安全和环境质量。这些都是加拿大各级政府目前的优先事项。

Reservoir outflows and dam failures pose significant flood risks with related downstream economic and life safety impacts. The artificial lakes formed and extreme or regulated river flows induced by such systems may cause irreversible environmental damage and threaten aquatic ecosystems. Land use practices in the surrounding region may exacerbate such risks through their effects on watershed hydrology and settlement patterns, and the release of non-point source pollutants. Given the potential for severe consequences, methods that provide rational and transparent bases for assessing such risks in the face of climate change and other uncertainties, and accounting for them in reservoir operating and watershed management decisions are needed. This project: i) advances water quality models for identifying downstream environmental impacts and their interactions with fish populations and habitat, of reservoir outflows, and develops measures for estimating the risk of such consequences; ii) develops a reservoir operating decision-making framework that considers environmental, fisheries, and life safety risks in the face of climate and land use change; and iii) develops methods that account for uncertainty in estimating the environmental and flooding consequences of land uses. The models and methods developed will be designed to identify the degree of exposure to the risks, characterize the ability of a system to recover from them in the short- or long-term, signal when the consequences may be irreversible and account for changes in precipitation patterns and land use practices. They may be used to support the planning and operation of reservoir systems and regional participatory water use planning processes. The findings will be of direct benefit to power and water utilities in managing their risk portfolio and maintaining their permission to operate and to regional water use managers and communities as they evaluate tradeoffs between the benefits of the various water and land uses and the cost of water shortages, environmental damage, and changes in system hydrology. They will enhance responsible management of large assets and improve public safety and environmental quality. These are ongoing priorities for all levels of government in Canada.