An assessment of the fine sediment dynamics in an upland river system: INCA-Sed modifications and implications for fisheries

Research output: Contribution to journalArticleScientificpeer-review


  • Attila N. Lazar
  • Dan Butterfield
  • Martyn N. Futter
  • Katri Rankinen
  • Marie Thouvenot-Korppoo
  • Nick Jarritt
  • Deborah S L Lawrence
  • Andrew J. Wade
  • Paul G. Whitehead

Research units

  • University of Reading
  • The James Hutton Institute
  • Finnish Environment Institute
  • Norwegian Water Resources and Energy Directorate
  • University of Oxford


There is a need for better links between hydrology and ecology, specifically between landscapes and riverscapes to understand how processes and factors controlling the transport and storage of environmental pollution have affected or will affect the freshwater biota. Here we show how the INCA modelling framework, specifically INCA-Sed (the Integrated Catchments model for Sediments) can be used to link sediment delivery from the landscape to sediment changes in-stream. INCA-Sed is a dynamic, process-based, daily time step model. The first complete description of the equations used in the INCA-Sed software (version 1.9.11) is presented. This is followed by an application of INCA-Sed made to the River Lugg (1077km2) in Wales. Excess suspended sediment can negatively affect salmonid health. The Lugg has a large and potentially threatened population of both Atlantic salmon (Salmo salar) and Brown Trout (Salmo trutta). With the exception of the extreme sediment transport processes, the model satisfactorily simulated both the hydrology and the sediment dynamics in the catchment. Model results indicate that diffuse soil loss is the most important sediment generation process in the catchment. In the River Lugg, the mean annual Guideline Standard for suspended sediment concentration, proposed by UKTAG, of 25mgl-1 is only slightly exceeded during the simulation period (1995-2000), indicating only minimal effect on the Atlantic salmon population. However, the daily time step simulation of INCA-Sed also allows the investigation of the critical spawning period. It shows that the sediment may have a significant negative effect on the fish population in years with high sediment runoff. It is proposed that the fine settled particles probably do not affect the salmonid egg incubation process, though suspended particles may damage the gills of fish and make the area unfavourable for spawning if the conditions do not improve.


Original languageEnglish
Pages (from-to)2555-2566
Number of pages12
JournalScience of the Total Environment
Issue number12
Publication statusPublished - May 2010
MoE publication typeA1 Journal article-refereed

    Research areas

  • Atlantic salmon, INCA, Lugg, Process-based model, Salmo salar, Sediment, Semi-distributed

ID: 10460144