Pathogen Risks in Agricultural Catchments: Towards International Collaboration And Learning in Modelling (PRACTICAL Modelling)
Members of the DHW team at Stirling (Oliver, Quilliam) along with colleagues at Durham University (Reaney) secured funding to support a 9-month project to add value to existing NERC funded science in the field of diffuse microbial pollution and risk-based modelling. The project – Pathogen Risks in Agricultural Catchments: Towards International Collaboration And Learning in Modelling (PRACTICAL Modelling) brought together Scientists from Stirling & Durham University and international expertise from the US Dept for Agriculture (USA) and AgResearch Ltd (New Zealand).
Around the world the prediction of microbial water pollution is important for informing policy decisions in order to safeguard human health. However, modelling the fate and transfer of microbial pollutants, such as E. coli (& other pathogens) at different spatial scales poses a considerable challenge to the research and policy community. In the UK much research has focused on trying to understand the movement & survival of pathogens in environmental systems with a view that better knowledge and data on the behavioural characteristics of these micro-organisms will improve our ability to model and predict their interactions with, and responses to, the world around us. The NERC-funded project ReMOFIO (www.remofio.stir.ac.uk) provides an example of research undertaken in the UK to improve our understanding of the magnitude and spatial distribution of microbial risks in the landscape. In turn, this new knowledge has enabled the refinement of a simple modelling framework (www.nercviper.ac.uk) to allow for improved prediction of microbial risk on agricultural land, based on livestock numbers, farming practices and E. coli survival patterns under environmental conditions (e.g. rainfall and temperature fluctuations). We now need to connect our understanding of environmentalÃ‚Â E. coli Ã‚Â loading with models that consider hydrological connectivity through the landscape (e.s. SCIMAP) for better assessments of when and where E. coli risks materialise in catchment systems. However, our models are built using data common to the UK; the PRACTICAL Modelling International Opportunity Fund (IOF) has enabled us to test the NERC funded ViPER and SCIMAP models in landscapes typical of different catchment systems around the world and to determine how transferable the approaches are beyond the UK in order to evaluate their global relevance. We have used the ‘PRACTICAL Modelling’ IOF to establish a new international partnership, with the UK acting as a ‘junction-box’ connecting data and modelling skills from across Ireland, New Zealand and the USA. We enlisted the expertise (and associated catchment data and modelling approaches) of three leading international scientists, in addition to other UK experts, in order to evaluate the wider application of data emerging from the NERC funded ReMOFIO and ViPER projects, coupled with the SCIMAP risk-based modelling approach to diffuse pollution. We are also investigating the potential for other models and tools to be linked to the ViPER model to see if, conceptually, we can develop a more holistic model that becomes bigger than the sum of its internationally disparate parts.
Part of our assessment has focused on the strengths and weaknesses of different modelling approaches that are currently being applied to assess pathogen risks in agricultural catchments. We are considering the transferability of these different approaches across contrasting agricultural systems typical of the UK, US, Ireland and New Zealand with a focus on the inherent differences in catchment characteristics (natural, managed, engineered and socio-economic), uncertainties of the underpinning data provided by international colleagues, and how these factors might impact on our ability to adopt or combine international modelling platforms. Our international partnership has explored key questions that challenge scientists working in the field of microbial pollution from agriculture: how do the different pathways in the soil, that connect pathogen sources to water bodies, vary in space & time across different catchment types & how does this impact on microbial travel times through the environment; to what extent does the probability of pathogen die-off vary for different environmental conditions around the world; how do we integrate pathogen behavioural characteristics (e.g. their ability to persist or move in the environment) into risk-based models that are useful for policy-makers; and how will the export of microbial pollutants from the landscape alter under projected climate change?
Using an international forum the PRACTICAL Modelling project is developing a global ‘roadmap’ of research priorities and needs required for a co-ordinated response to improve the prediction of microbial risks in agricultural landscapes.
(Photo Credits: Sim Reaney, Durham University)