A Coastal Hard Rock Sediment Budget for the Inner Bristol Channel

by A. T. Williams, Polytechnic of Wales, United Kingdom,
P. Davies, Polytechnic of Wales, United Kingdom,



Document Type: Proceeding Paper

Part of: Sediment Transport Modeling

Abstract:

The dominant input into the inter-tidal zone from the hard rocks bordering the inner Bristol Channel is clastic material. This is derived from coastal recession as a result of subaerial and marine processes. Recession rates, cliff height and outcrop length combine to give calculated sediment supplies of 50 ? 10³ m³ of Trias, 35 ? 10³ m³ of Jurassic and 42 ? 10³ m³ of Devonian derived sediments to the system. Gravels and muds predominate in the supply with only some 17 ? 10³ m³ of sand sized sediments arising solely from breakdown of Devonian rocks. Large scale sinks within the system have a 125 -200 year supply of clastic inputs. Sink volumes for the northern shore have been measured as 2.5 million m³. For the southern shore, site sampling gave values of about 900,000 m³ (Porlock) and 350,000 m³ (Blue Anchor Bay). Total sink volumes for the southern shore exceeds those of the northern shore.

Subject Headings: Coastal processes | Sediment | Rocks | Shores | Channels (waterway) | Sediment transport | Light rail transit

Services: Buy this book/Buy this article

 

Return to search