Stepwise development of catchment hydrology for effect modelling in regulatory landscape-scale aquatic risk assessment

Florian Krebs^1,2, Sebastian Multsch¹, Philipp Kraft², Lutz Breuer², Louise Wipfler³, Wim Beltman³, Thorsten Schad<sup>4

1 knoell Germany GmbH
2 Chair of Landscape, Water and Biogeochemical Cycles, Justus Liebig University Giessen
3 Wageningen Environmental Research
4 Bayer AG, Research & Development, Crop Science</sup>

The EFSA Guidance Document on Aquatic Risk Assessment (EFSA, 2013) indicates a key role for effect modelling in future aquatic risk characterisation in a tiered risk assessment framework. Such approaches require correspondingly adapted exposure tools and scenarios ranging from simple edge-of-field to spatio-temporally explicit landscape scale catchment models. These approaches should be sufficiently flexible and transparent in order to design lower- and higher-tiers of consistent protection levels. On the catchment scale, a hydrological model needs to be set up with explicit locations of fields and streams. Furthermore, the simulation time steps should be in an appropriate resolution (e.g. 1 h) in order to cover exposure profile resolutions needed for a proper effect assessment. In the present study, a flexible modelling setup using the Catchment Modeling Framework CMF (Kraft et al. 2011) is introduced.

This generic framework allows developing model setups adapted to the data availability for the catchment of interest.

The aim is to produce spatially and temporally explicit calculations of Predicted Environmental Concentrations allowing to analyse effects at the landscape scale for regulatory aquatic risk assessment.

Event: SETAC Europe, Dublin 2020