Suspended sediment dynamics during storm events in urban catchments (River Tame: West Midlands, UK)

摘要

The study used continuously monitored, high resolution turbidity, ammonia, rainfall and flow data from EA UK. Urban storm events were not systematically characterised previously leading to gaps in process understanding; previous studies used short time periods and with most of them formed on single gauges. Aimed at improving understanding with novel contributions, the objectives were characterising the events, finding their seasonal influence and the spatial scale effect on turbidity patterns.ududUniversally adaptable quantified events characterisation and classification were developed yielding single, double and multiple events. Double and multiple events together was more than single events for both smaller and larger catchments. Thus, analysing only single events could miss key dynamics of multiple events which showed significant increases in turbidity. More anticlockwise events than clockwise were found. Anticlockwise events decreased and clockwise increased from single to multiple events. Events with more number of turbidity than discharge peaks were found.ududSeasonally, most attributes as well as high urban extent and effluent spillage showed significant effects on turbidity mostly in summer and autumn. All seasons but spring with more anticlockwise than clockwise events had more low flows. Winter had the highest anticlockwise events, possibly because of its wider areal rain event extent, high number of low flows as well as more distal runoff sources.ududIn the spatial scale studies, more single events in the smaller and more multiple events in the larger catchments as well as more anticlockwise events in the smaller and more clockwise events in the larger catchment were found.ud