Changes in sediment flux and storage within a fluvial system: some examples from the Rhine catchment



The Rhine river system can look back on a long history of human impact. Whereas significant anthropogenic changes to the river channel started only 200 years ago, the impacts of land use have been felt for more than 7500 years. Here, we review results from several case studies and show how land-use change and climate impacts have transformed the fluvial system. We focus on changes in sediment delivery pathways and slope–channel coupling, and show that these vary in time and depend on the magnitude of a rainfall event. These changes must be accounted for when trying to use sediments as archives of land-use change and climatic impacts on fluvial systems. For example, human impact is recorded in slope deposits only as long as rainfall intensity and runoff generation do not exceed the threshold for gullying. Similarly, climatic impacts are only recorded in alluvium when both the landscape is rendered sensitive by human activities (e.g. deforestation) and rainfall thresholds for gullying are exceeded. Copyright © 2003 John Wiley & Sons, Ltd.