Hydrological events, caused also by relevant weather occurrences, are an increasingly frequent problem. Floods, landslides and landfalls testify the vulnerability of our territory and sometimes they are caused by the sudden changes of land use. Neglecting the terraced landscape, for example, modified (and sometimes reduced) the drainage capacity of the water network surface, increasing the hydrological risks. This paper regards two neighborhoods of Trieste, a little town of Northeastern Italy, affected few years ago by micro-hydrological events. It aims to describe their recent history in order to understand how (and if) main changes of land use modified their delicate drainage system. For these reasons we compare non-homogeneous cartographical sources: the Catasto Franceschino maps, realized during the first years of the 19th century, some photograms IGM of the 1957 and some recent ortophotos (2007).
