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Extending SCIMAP to predict E. coli delivery risk to surface waters

Agricultural practices contribute a significant amount of faecal material onto pasture via direct defecation by grazing livestock and through applications of solid and liquid manures. Managing the spatial and temporal input of this faecal loading to pasture is important in order to minimise the proportion of FIOs, e.g. E. coli, which may be washed from faecal sources and transferred in runoff to nearby watercourses following rainfall. Contaminated runoff can lead to microbial pollution of our streams, rivers and seas. Over the last 10 years Dr David Oliver and Prof Louise Heathwaite have developed a model of E. coli survival in agricultural systems to improve our understanding of the magnitude and spatial distribution of microbial risks in the landscape. That model is capable of predicting levels of E. coli on agricultural land, based on livestock numbers, farming practices and E. coli persistence patterns under environmental conditions (e.g. rainfall and temperature fluctuations). While the model is structurally simple its operation & functionality it was not originally designed to maximise uptake by those who would benefit most from its use.

Livestock in the catchment are a key source of E. Coli. which effects bathing waters

In response, the original Visualising Pathogen & Environmental Risk (ViPER) project developed a freely-available prototype decision support tool (DST) called ViPER (www.nercviper.co.uk). The ViPER DST provides a user-friendly interface and allows end-users, without specific modelling skills to understand how, when and where E. coli risks accumulate on agricultural land. However, ViPER was unable to determine what proportion of that E. coli source on agricultural land would actually end up in rivers and streams following rainfall. To do this analysis requires an understanding of hydrological connectivity in the landscape and so the ViPER team began to discuss opportunities of linking with the SCIMAP approach.

Bathing waters can be effected by E. Coli.

ViPER2 – building SCIMAP-FIO: With support from NERC the ViPER II project will combine the ViPER DST with SCIMAP. SCIMAP currently does not map microbial risks in the landscape because, unlike sediment and nutrients, bacteria such as E. coli accommodate a complex life-cycle and will die-off over time. By contrast, ViPER is able to account for the die-off of E. coli but lacks the capacity to predict E. coli transfer with runoff. Over the next 12 months, the project team will build SCIMAP-FIO and make it available as part of the my.SCIMAP web application.

FIO lab samples
Lab samples from monitoring E. Coli levels in rivers

This work is funded by NERC and involves Dr David Oliver, Dr Phil Bartie, Dr Jared Parnell and Dr Richard Quilliam (Stirling University) are collaborating with Dr Sim Reaney (Durham University) and Prof Heathwaite (Lancaster University). NERC ref NE/P016332/1