A moni-modelling approach for risk management of pesticide at territorial level

In general, approaches used by water quality managers to preserve water bodies from the risks associated to the use of Plant Protection Products (PPPs) fall within two categories: monitoring campaigns or predictive models. Both approaches show pro and cons. Monitoring programs are required in current EU regulations, as they are very useful to verify whether the concentration of chemicals exceed predetermined trigger values (i.e. for PPPs it is 0.1 μg/L in groundwater). On the other hand, they represent a single point in space and time (static), in a situation in which different dynamic processes act at the same time; consequently, they cannot be used to forecast the future state of the environment. On the other hand, predictive models are very useful to spatially represent the forecasted contamination starting from several sources on the territory. However, they rely on assumptions, mainly related to the parameterisation of the model inputs which could introduce biases and uncertainties in the spatial estimation of pesticide transport toward water resources. In our opinion, a new methodology that provides the integration of both approaches (what we here call moni-modelling approach) could provide invaluable help for risk managers. In fact, this approach would be very useful, particularly on a territorial scale, for a proper risk management of PPPs. In fact, it would be helpful to: a) identify sensible areas where implement mitigation measures or limitation of use, b) re-design future monitoring plans, c) better calibration of the pedo-climatic input data for the environmental fate models. As a case study, the proposed approach has been applied to Lombardy region (a NUTS 2 zone in North of Italy) using six active ingredients with different leaching behaviours.