Hydromorphological adjustment in meandering river systems and the role of flood events

摘要

This paper takes a selection of meandering rivers in the UK to address issues of morphological adjustment and change. The occurrence of peak flow events over recent decades is analysed for patterns and trends. Certain hydrological phases are identifiable. Changes in morphology and activity of the channels are examined through repeat field and aerial photograph mapping and some detailed observations over a period of 20 years. These show major variations, some of which appear to be related to discharge fluctuations The differing impact of the highest floods within the period of record is demonstrated. The state of the system, particularly the degree of meander development, is of crucial importance. A seasonal difference in the impact of high flow events is also detected. Relationships between morphological changes and discharge characteristics are complex and the effects of other factors, particularly growing season and ramped effects of growth of vegetation may be significant.