Soil erosion, sediment sources, connectivity and suspended sediment yields in UK temperate agricultural catchments Discrepancies and reconciliation of field-based measurements

A - Papers appearing in refereed journals

Pulley, S. and Collins, A. L. 2024. Soil erosion, sediment sources, connectivity and suspended sediment yields in UK temperate agricultural catchments Discrepancies and reconciliation of field-based measurements. Journal of Environmental Management. 351, p. 119810.

AuthorsPulley, S. and Collins, A. L.

Robust understanding of the fine-grained sediment cascades of temperate agricultural catchments is essential for supporting targeted management for addressing the widely reported sediment problem. Within the UK, many independent field-based measurements of soil erosion, sediment sources and catchment suspended sediment yields have been published. However, attempts to review and assess the compatibility of these measurements are limited. The data available suggest that landscape scale net soil erosion rates (∼38 t km−2 yr−1 for arable and ∼26 t km−2 yr−1 grassland) are comparable to the typical suspended sediment yield of a UK catchment (∼44 t km2 yr−1). This finding cannot, however, be reconciled easily with current prevailing knowledge that agricultural topsoils dominate sediment contributions to watercourses, and that catchment sediment delivery ratios are typically low. Channel bank erosion rates can be high at landscape scale (27 km−2 yr−1) and account for these discrepancies but would need to be the dominant sediment source in most catchments, which does not agree with a review of sediment sources for the UK made in the recent past. A simple and robust colour-based sediment source tracing method using hydrogen peroxide sample treatment is therefore used in fifteen catchments to investigate their key sediment sources. Only in two of the catchments are eroding arable fields likely to be important sediment sources, supporting the alternative hypothesis that bank erosion is likely to be the dominant source of sediment in many UK catchments. It is concluded that the existing lines of evidence on the individual components of the fine sediment cascade in temperate agricultural catchments in the UK are difficult to reconcile and run the risk of best management interventions being targeted inappropriately. Recommendations for future research to address paucities in measured erosion rates, sediment delivery ratios and suspended sediment yields, validate sediment source fingerprinting results, consider the sources of sediment-associated organic matter, and re-visit soil erosion and sediment cascade model parameterisation are therefore made.

KeywordsSediment pollution; Sediment cascade; Diffuse pollution mitigation; Field monitoring
Year of Publication2024
JournalJournal of Environmental Management
Journal citation351, p. 119810
Digital Object Identifier (DOI)
Web address (URL)
Open accessPublished as ‘gold’ (paid) open access
FunderBiotechnology and Biological Sciences Research Council
Funder project or codeResilient Farming Futures (WP2): Detecting agroecosystem ‘resilience’ using novel data science methods
Environment Agency project 19936 (Catchment Sensitive Farming programme)
NE/V007262/1 UKRI-NERC (UK Research and Innovation-Natural Environment Research Council) Urgency grant award
Northumbrian Water and the Coal Authority via the Tyne Rivers Trust
Publisher's version
Copyright license
Output statusPublished
Publication dates
Online14 Dec 2023
Publication process dates
Accepted07 Dec 2023

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