GRRR. The EXPECT groundwater model for transport of solutes

In this report the design and first test results are presented of the EXPECT groundwater module for transport of solutes GRRR (GRoundwater source Receptor Relationships). This model is one of the abiotic compartment modules of the EXPECT model. The EXPECT model is a tool for scenario development of environmental policy plans. It covers the pathway of environmental pollutants from emissions to effects on biotic and abiotic receptor systems. The GRRR model computes the transport of solutes in the groundwater compartment by means of source-receptor relationships. These relationships are derived with the National Groundwater Model (LGM) developed at LBG, RIVM. This approach results in a fast calculating model which produces results in an aggregated format. Example results illustrate the way the model works. Based on three fictious scenarios, nitrogen contents have been computed in shallow and deep groundwater layers. The conclusion was made that the model is suited to perform scenario analyses, but for extreme scenarios or for detailled calculations a research model like LGM is better suited.<br&gt