Keith Richards, 2002. "Drainage basin structure, sediment delivery and the response to environmental change", Sediment Flux to Basins: Causes, Controls and Consequences, S.J. Jones, L.E. Frostick
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The purpose of this paper is to explore the role that drainage basins and networks play in filtering and modulating the effects of environmental change. The record of this change is often inferred from the properties of alluvial stratigraphy in river valleys. However, the variable time lags and smoothing effects caused during the flux of sediment through a drainage basin are very poorly understood, and need to be clarified before the depositional record can be linked to the causes of change. Interactions amongst drainage network elements – main valleys and tributaries – result in complex patterns of storage and delivery in time and space, and these interactions are reviewed in this paper. While the combination of cosmogenic isotopic dating of erosional records, and the use of shallow seismic and ground penetrating radar methods may provide data on the empirical linkages between sediment sources and sinks, a significant research need is for a modelling framework to enable cut-and-fill records to be simulated, and to provide a rigorous connection between the valley-fill depositional record and the environmentally-driven variations in sediment production. This will require a return to the long-neglected analysis of drainage network structure, and an improved understanding of the within-catchment variations in the sediment delivery ratio. Until this is achieved, it will be premature to assume direct connections between environmental change and the record of alluviation in many valleys.
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There is an increasing trend in the Earth sciences towards the integration of many subdisciplines. The sedimendatry basin, is a fundamental focal point of many studies, which as a consequence often neglects the complimentary drainage basin or catchment. Sedimentary basins provide a record of Earth history, reflecting the geographical, lithological, oceanographic and ecological development through the rock record. Drainage basins in comparison record ephemeral landscape evolution, where topography is eroded and provides the flux of sediment to the basin. The basin fill reflects the sediment flux from the hinterland and provides evidence of the dynamic geomorphic processes. In context the drainage system and sedimentary basin can be regarded as a ‘production line’ with sedimentary record giving valuable insight into long-term landscape evolution and geomorphological processes illuminating the evolution of sedimentary basins.
This volume assesses the current position of understanding sediment supply to basins with the integration of the many sub-disciplines in the Earth sciences. It documents a mix of hinterland and sedimentary basin studies with a gradation from orogenic belts to the deep marine. The authors represent a wide spectrum of Earth scientist, with leaders in the science providing review papers and new-directive papers in their field of specialization.