River sediment supply, delta formation and adjacent shelf processes: conference report and introduction

Abstract

Although an improvement in the exchange of scientific results has taken place between natural scientists and the engineering community over the past decade, there is a need for even more integration between the disciplines. Similarly, there is a need for marine geologists to understand there is a need for marine geologists to understand headwater river processes and vice versa . The meeting held at the Geological Society on 17 May, 1984 was organized in an attempt to improve such scientific exchanges, on an international basis. The following review of the presentations at the meeting serves to introduce this thematic set. They are arranged from headwater catchment to continental shelf. Following an introduction by Collins to some of the processes and controls involved in the transfer of fluviatile sediments to the deep ocean, Moore & Newson described 10 years of measurements of sediment yield from semi-natural grassland and commercially afforested catchments in the British Isles. Field investigations using bed load traps were compared with hydrological and transport capacity factors. Channel storage and release of material is identified as a critical control on bedload yields. Based upon estimates of the solid and solute load passing 13 gauging stations in the Southern Grampian Highlands of Scotland, an apparently anomalous increase in sediment yield with increase in catchment area in a seaward direction was observed by McManus. This anomaly is attributed partly to the presence of organic matter in the waters. 50% of the annual total suspended load entering the Tay and Forth estuaries