after a PhD at Université d'Orleans and a post-doctoral position at Wallingford with Colin Neal, on the topic of the acidification of semi natural mountainous ecosystems, I took a permanent position as a full time researcher at INRA (which became INRAE in 2021). I have been working in Rennes eversince, principally on the issue of nitrate pollution by agriculture. I developped the TNT2 model, a fully distributed model coupling an hydrological model and a crop model. Most of my research was on modelling hydrology and nitrogen cycling in temperate humid headwater catchments. I contributed to five european projects (NitroEurope was the last one) and coordinated one chapter on the European Nitrogen Assessment. I worked as the head of my research unit (UMR SAS, 100 collaborators, annual budget > 1 M€ excluding permanent staff salary) during eight years and I am know part of the direction team of the AQUA research department (permanent staff >300, 16 research units). I am strongly involved in support to policy and to stakeholders in water resource management, both as the principal scientist of many projects funding by public bodies to evaluate and design mitigation measures of nitrate polution and as an expert acting in science- society mediation, especially within the CRESEB (centre de ressources et d'expertise sur l'eau en Bretagne-resource center on water in Brittany).