GLOBAL-FATE (version 1.0.0): A geographical information system (GIS)-based model for assessing contaminants fate in the global river network

Abstract. GLOBAL-FATE is the first open-source, multiplatform, user-friendly, and modular contaminant-fate model operating at the global scale linking human consumption of pharmaceutical-like compounds with their concentration in the river network. GLOBAL-FATE simulates human consumption and excretion of pharmaceuticals, the attenuation of the contaminant load in waste water treatment plants as well as the attenuation of the contaminant load in river reaches, lakes, and reservoirs as a first-order decay depending on residence time. We provide a comprehensive description of model equations and the overall structure of the model, with special attention to input–output datasets. GLOBAL-FATE is written in C, can be compiled in any platform, and uses inputs in standard geographical information system (GIS) format. Additionally, the model can be run in the Quantum Geographic Information System (QGIS) as a plug-in. The model has no built-in working resolution, which depends on the intended use and the availability of appropriate model inputs and observed data. We exemplify the application of GLOBAL-FATE solving the global concentration of diclofenac in the river network. A comparison with a dataset of diclofenac concentration observations in rivers suggests that GLOBAL-FATE can be successfully applied in real-case modelling exercises. The model is particularly sensitive to the generation of contaminant loads by human pharmaceutical consumption and to the processes governing contaminant attenuation in the river network. GLOBAL-FATE will be a valuable tool for the scientific community and the policymaking arena and could be used to test the effectiveness of large-scale management strategies related to pharmaceutical consumption control and waste water treatment implementation and upgrading.