Indices and indicators of water sustainability: systems analysis approach

Water is not only essential to sustain life, but to support ecosystems, economic development, community well-being, and cultural values. In the context of fresh water resources, any discussion of sustainable development requires that we understand both the physical resource and the benefits or services that those resources must provide. In order to make decisions about how to allocate and use water resources, some specific approaches and tools need to be identified. A holistic, systems approach can help to understand the role and relative influence of factors within a system, By identifying key linkages it can suggest ways that decisionmakers might influence the path of development and improve quality of life, while taking account of a wide range of economic, social, and environmental considerations. Modeling is a principal tool for studying the behavior of large, complex systems such as environmental or social systems. Most existing models do not include the final logical step - i.e., addressing the balancing of pros and cons of possible impacts in order to reach a decision related to given policies or assessment objectives. This is the unique point where environmental indicators and indices can be particularly beneficial - that is, by reducing subjectivity and complexity. The article examines the existing conceptual and integrated models of water systems (i.e. environmental, economic, social and technological) dynamics, and their links with the systems of indices and indicators of water sustainability. Using the response function models as an integrated framework, a set of indicators and indices of water sustainability is developed as an important tool for converting quantities of environmental data and output of models into succinct information that can be readily understood and used by decision-makers and the general public. Water Resilience Index (WRI) is presented as an example of the proposed approach and modelling techniques.