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

水库外流和大坝坍塌带来了重大的洪水风险，并对下游经济和生命安全产生了相关影响。这些系统形成的人工湖和极端或调节的河流流量可能会造成不可逆转的环境破坏，并威胁到水生生态系统。周边地区的土地利用做法可能会对流域水文和定居模式以及非点源污染物的排放产生影响，从而加剧这种风险。鉴于可能出现严重后果，需要在面对气候变化和其他不确定性的情况下为评估这种风险提供合理和透明的基础，并在水库运营和流域管理决策中考虑到这些风险。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的相互作用，以及水库外流的影响，并制定评估这种后果的风险的措施；ii)制定一个在面对气候和土地利用变化的情况下考虑环境、渔业和生命安全风险的水库运营决策框架；iii)制定在估计土地利用的环境和洪水后果方面的不确定性的方法。所开发的模型和方法将旨在确定风险的暴露程度，确定系统在短期或长期内从风险中恢复的能力，并在后果可能不可逆转时发出信号，并考虑到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进程。研究结果将直接有利于电力和自来水公司管理其风险组合并保持其运营许可，以及区域用水管理人员和社区在评估各种水和土地利用的好处与水资源短缺、环境破坏和系统水文变化的成本之间的权衡时。他们将加强对大笔资产的负责任管理，改善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.