Case Study: Requirements for Cumulative Effects Analysis

Changes in the geomorphology and ecology of fluvial systems are often the result of both natural and man-induced influences. Assessment of cumulative effects on fluvial systems is necessary to understand the involved influences, characterize the direction and trend of environmental change, describe the relations between physical and biological conditions, and provide a basis for management decisions. A case study for cumulative effects analysis is a recently completed study of the Upper Mississippi River (UMR). The UMR has been strongly influenced by the development of navigation, watershed reservoirs, agricultural land-use practices, construction of levee systems, and possibly global warming. Analysis techniques to describe environmental change and forecast future ecological conditions are described. Strengths and weaknesses of the analysis methodology are reviewed. Recommendations for future cumulative effects analyses are provided.