Investigating spatial patterns of overbank sedimentation on river floodplains

• Published in: Water, air, and soil pollution Vol. 99; no. 1-4; pp. 9 - 20
• Main Authors: Walling, D. E., He, Q.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Dordrecht Springer 01.10.1997
• Subjects: Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; Freshwater; Marine and continental quaternary; Pollution, environment geology; Surficial geology; England; United Kingdom; Great Britain; Devonshire England; Western Europe; British Isles, England, Devon, Culm R; Europe; Cs-137; sampling; Carboniferous; Pb-210; radionucleids; radioactive fallout; pollution; sedimentation rates; sedimentation; Paleozoic; floodplains; Lower Carboniferous; Culm; hydraulics; upper Paleozoic; fallout; Dinantian; spatial variations
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/BF02406840

Attempts to study spatial patterns of overbank sedimentation on river floodplains commonly face important operational and sampling problems in documenting deposition rates. Recent advances in the application of fallout radionuclides ( super(137)Cs and unsupported super(210)Pb) to the estimation of medium-term rates of overbank sedimentation offer an essentially unique opportunity to assemble detailed distributed data sets for medium-term deposition rates. Such data can afford a valuable basis for investigating the complex relationship between sedimentation rates and floodplain microtopography and morphology and flow hydraulics. This paper reports the results of an investigation of the spatial pattern of overbank sedimentation rates on the floodplain of the River Culm, Devon, UK. Caesium-137 and unsupported super(210)Pb measurements have been used to establish the general pattern of deposition rates along an 11 km reach and more intensive measurements have been employed to document the detailed pattern existing within a small area subject to frequent inundation. The resultant data have been used as a basis for interpreting the major controls on the observed patterns.