Modelling of phosphorus inputs to rivers from diffuse and point sources.
Bowes, Michael J.; Smith, Jim T.; Jarvie, Helen P.; Neal, Colin. 2008 Modelling of phosphorus inputs to rivers from diffuse and point sources. Science of the Total Environment, 395 (2-3). 125-138. 10.1016/j.scitotenv.2008.01.054Full text not available from this repository.
The difference in timing of point and diffuse phosphorus (P) delivery to a river produces clear differences in the P concentration – flow relationship. Point inputs decrease in concentration with increasing river flow, due to dilution of a relatively constant input, whereas diffuse load usually increases with river flow. This study developed a simple model, based on this fundamental difference, which allowed point and diffuse inputs to be quantified by modelling their contribution to river P concentration as a power law function of flow. The relationships between total phosphorus (TP) concentration and river flow were investigated for three contrasting UK river catchments; the Swale (Yorkshire), the Frome (Dorset) and the Avon (Warwickshire). The model was fitted to this empirical data to give estimates of point and diffuse load inputs at each monitoring site, at high temporal resolution. The model produced TP source apportionments that were similar to those derived from an export coefficient approach. For many diffuse-dominated sites within this study (with up to 75% of the annual TP load derived from diffuse sources), the model showed that reductions of point inputs would be most effective in order to reduce eutrophication risk, due to point source dominance during the plant and algae growing period. This modelling approach should provide simple, robust and rapid TP source apportionment from most concentration – flow datasets. It does not require GIS, information on land use, catchment size, population or livestock density, and could provide a valuable and versatile tool to catchment managers for determining suitable river mitigation options.
|Programmes:||CEH Programmes pre-2009 publications > Water > WA03 Developing strategic data and knowledge at a catchment scale to enable the wiser management of the water environment > WA03.3 Catchment scale modelling and assessment|
|Additional Keywords:||Eutrophication, Source apportionment, Point source, Diffuse source, Agriculture, Sewage, Nutrient, Load apportionment model|
|NORA Subject Terms:||Hydrology
|Date made live:||20 May 2008 14:47|
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