The Role of Reliability, Vulnerability and Resilience in the Management of Water Quality Systems

Abstract

The risk based performance indicators reliability, vulnerability and resilience provide measures of the frequency, magnitude and duration of the failure of water resources systems, respectively. They have been applied primarily to water supply problems, including the assessment of the performance of reservoirs and water distribution systems. Applications to water quality case studies have been limited, although the need to consider the length and magnitude of violations of a particular water quality standard has been recognized for some time. In this research, the role of reliability, vulnerability and resilience in water quality management applications is investigated by examining their significance as performance measures for water quality systems and assessing their potential for assisting in decision making processes. The importance of each performance indicator is discussed and a framework for classifying such systems, based on the relative significance of each of these indicators, is introduced and illustrated qualitatively with various case studies. Quantitative examples drawn from both lake and river water quality modeling exercises are then provided.