Assessing potential impact to ground water in the EU and Member State registration procedures

Abstract

A FOCUS work group was established in 2004 to update the EU ground water assessment procedures. The work group has proposed a four tier ground water assessment process considering initial modelling, experimental studies, more advanced modelling, approaches combining experiments with modelling, and ground water monitoring. The work group made minor changes to the soil profiles in the Piacenza and Porto scenarios to make them more representative of their respective agricultural regions.

Harmonization has concentrated on the dispersion length and the water balance. Water balance changes include a switch from the potential evapotranspiration calculated by MARS to that calculated by FAO for the five southern scenarios, development of irrigation schedules for each of the irrigated crops which are calibrated to the amounts actually used in the region, implementation of time varying crop coefficients in all models, standardisation of soil evaporation when no crops are present, and harmonisation of runoff amounts.

Several different modelling approaches have been evaluated including GIS procedures, inverse modelling, specifying soil specific degradation sorption parameters, and non-equilibrium sorption. Two different approaches to GIS evaluations have developed for selection of regional crop-specific scenarios. The existing nine FOCUS scenarios cover most areas in the new member states for the purpose of Tier 1 simulations.