J. Green M.W. Trett The Fate and Effects of Oil in Freshwater 1990 Elsevier Applied Science The Hague 1 85166 318 5

Abstract

Environmental flows assessments use advanced hydrologic and hydraulic modeling techniques to quantify changes in flow regime and aquatic habitats. However, predictions of ecological responses to these changes are often based upon expert opinion or limited quantitative relationships between flow, habitat, and ecological response. Increasing knowledge of ecological responses to changing flow regimes, along with the emergence of new and powerful modeling approaches, means that statistical models of ecological response can be used more effectively in environmental flows assessments. We describe a process that environmental flows assessment teams could use to identify, modify, or develop models of ecological response to changing flow regime. We describe several major modeling approaches that can be used to test hypotheses and to quantify cause–effect relationships, and then classify these approaches according to their requirements for ecological knowledge and data. Some modeling techniques are simple to implement and could be employed in many environmental flows assessment projects. Others are more demanding to develop and implement, potentially requiring additional ecological modeling expertise as part of environmental flows assessment teams. Capacity for modeling ecological responses to changing flow regimes will evolve over time as part of monitoring and adaptive management of environmental water release decisions. However, sufficient data, expertise, and approaches already exist for ecological models to be employed more insightfully and far more often in environmental flows assessments.