In this chapter we will address, with quick notes, some research projects that the University of Florence has undertaken and which have seen the Arno basin as a subject of study, in order to define lines of governance and development of the territory, also on the basis of an international network which has made it possible to introduce innovative elements of approach and scientific investigation. These are aspects that concern agricultural production, hydraulic and environmental engineering, the protection of water resources, the control of hydrogeological instability, soil protection, urban and territorial planning. We have therefore tried to represent in a rational form some research topics that have been addressed, trying to grasp, over time, the purposes and main impacts