A spatialising tool to simulate pesticide fate in the unsaturated zone on a catchment scale

A tool has been designed to calculate the leaching potential of pesticide on a catchment scale using the one-dimensional pesticide leaching model MACRO. The tool is able to collect the input data of the study area in a grid with homogeneous cells and prepare spatially distributed data required by MACRO. Successively, the tool can run multiple MACRO simulations for each cell of the grid and organise output reports following the user's preference, as well as generate output files compatible with GIS and other environmental software applications. The tool was tested to simulate the behaviour in the unsaturated zone of water and pesticide isoproturon used on winter wheat at 1.75 kg ha-1 of active ingredient in a German study area for 10 years of meteorological data and for different crop-soil combinations. Maps of isoproturon concentration in the liquid phase were created using the spatialised output data from the tool.