Land use changes are some of the main drivers of pasture dynamics. During the last 100 years, in Iași county, some historical events, especially land reforms, have shaped the actual structure of the pastures. Revealing these changes, not just as total statistics but also as fluxes and at a spatial level, allows us to detect and associate them with the factors involved. We used a raster approach to change detection for a land-use-type database that extends to the 1920s. The database was created from topographic, remote sensing, and field data collected between 1920 and 2006, with five intervals between 1960, 1980, 1990, and 2000, starting from CORINE Land Cover data. These periods mark the socio-political and natural changes in the study area. The change detection results are well-matched with the identified drivers and their spatial distribution. The fluctuations between land-use types provide an essential way to create drivers’ associations. Our analysis can be easily applied to any other concerned areas and could be used as base references for any legislative intention to determine land-use-type changes because it can be learned from past conversions concerning failures or examples of good practice.