Risk assessment and mitigation of water quality systems: recoverable and non-recoverable responses to failure

点击翻译按钮获取中文摘要

Maintenance of water quality objectives in natural and constructed environments may be affected by events or inputs that are observable, such as variations in streamflow, and by those that are unobservable, such as mechanical failures, and by our limited understanding of the cause and effect relationships that govern such systems. The inputs may be stationary in nature, having a constant mean and standard deviation over time, or non-stationary, exhibiting changes in the statistical properties over time, due, e.g., to climate change. In any case, the expected water quality response to planning and operational decisions may be quite variable, failure to meet water quality objectives may be severe, and the consequences of such failures may be repairable, i.e., functioning, or non-repairable, not functioning, after failures occur. The types of decisions undertaken to protect water quality in different domains may differ; however the performance objectives are similar and focus on achieving water quality standards as reliably as possible. This project develops analytical techniques, including identification of reliability and other performance measures, for evaluating decisions regarding river water quality and water supply systems. This project will: 1) advance the use of performance measures for repairable river water quality management systems in cases where the system inputs are non-stationary. Methods for identifying planning decisions that adapt to changing input conditions will be developed and applied; 2) Develop and investigate the use of performance measures for evaluating when to upgrade water distribution system elements; and 3) Develop methods for estimating and practices for enhancing the reliability of water treatment technologies for meeting health targets.